Author: "Yonghua Li-Beisson" / Publisher: hal ccsd - Searchworks@Jio Institute Digital Library Search Results

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49 results on '"Yonghua Li-Beisson"'

1. Efficient approaches for nuclear transgene stacking in the unicellular green microalga Chlamydomonas reinhardtii

Author: Fantao Kong, Mengjie Li, Keqing Liu, Yunlong Ge, Tomohito Yamasaki, Audrey Beyly-Adriano, Takeshi Ohama, Yonghua Li-Beisson, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: [SDV]Life Sciences [q-bio], Agronomy and Crop Science
Abstract: International audience
Published: 2023

2. Cyclic and pseudo-cyclic electron pathways play antagonistic roles during nitrogen deficiency in Chlamydomonas reinhardtii

Author: Ousmane Dao, Adrien Burlacot, Marie Huleux, Pascaline Auroy, Gilles Peltier, Yonghua Li-Beisson, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes (LEMIRE)
Subjects: [SDV]Life Sciences [q-bio]
Abstract: Nitrogen (N) deficiency is a frequently encountered situation that constrains global biomass productivity. In response to N deficiency, cell division stops and photosynthetic electron transfer are downregulated, while carbon storage is enhanced. However, the molecular mechanism downregulating photosynthesis during N deficiency and its relationship with carbon storage are not fully understood. The Proton Gradient Regulator-like 1 (PGRL1)-involved in cyclic electron flow (CEF) and Flavodiiron proteins involved in pseudo-(CEF) are major players in the acclimation of photosynthesis. To determine the role of PGRL1 or FLV in photosynthesis under N deficiency, we measured photosynthetic electron transfer, oxygen gas exchange and carbon storage in the knockout of Chlamydomonaspgrl1 and flvBmutants. Under N deficiency,pgrl1maintains higher net photosynthesis and O2photoreduction rates, whileflvBshows similar responses compared to control strains. The amount of cytochromeb6fwas maintained at a higher level inpgrl1. The photosynthetic activity ofpgrl1 flvBdouble mutants decreases in response to N deficiency similar to the control strains. Furthermore, the triacylglycerol content ofpgrl1was twice higher than the controls under N deficiency. Taken together, our results suggest that in the absence of PGRL1, FLV-mediated O2photoreduction through PCEF maintains net photosynthesis at a high level, resulting in increased triacylglycerol biosynthesis. This study reveals that PGRL1 and FLV play antagonistic roles during N deficiency. It further illustrates how nutrient status can affect the regulation of photosynthetic energy production in relation to carbon storage and provides new strategies for improving lipid productivity in algae.Significance statementNitrogen (N) deficiency, an often-encountered phenomenon in nature, triggers growth arrest and massive lipid accumulation in microalgae. The downregulation of photosynthesis is necessary to ensure cell viability. We demonstrate that a well-conserved protein in chlorophytes, the Proton Gradient Regulator-like 1 (PGRL1) is a key (down) regulator of photosynthesis. In its absence, cells exhibited sustained photosynthesis and over-accumulated lipids thanks to the Flavodiiron (FLV) protein. We propose that both PGRL1 and FLV, by having antagonistic roles in N deficiency, manage the redox landscape, carbon storage and biomass production. Our work revolves around the current paradigm of photosynthesis regulation during N deficiency and provides a new framework for improving lipid accumulation in microalgae for biotechnological purposes.
Published: 2023

3. Alternative photosynthesis pathways drive the algal CO2-concentrating mechanism

Author: Adrien Burlacot, Ousmane Dao, Pascaline Auroy, Stephan Cuiné, Yonghua Li-Beisson, Gilles Peltier, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Multidisciplinary, [SDV]Life Sciences [q-bio]
Abstract: International audience; Global photosynthesis consumes ten times more CO2 than net anthropogenic emissions, and microalgae account for nearly half of this consumption1. The high efficiency of algal photosynthesis relies on a mechanism concentrating CO2 (CCM) at the catalytic site of the carboxylating enzyme RuBisCO, which enhances CO2 fixation2. Although many cellular components involved in the transport and sequestration of inorganic carbon have been identified3,4, how microalgae supply energy to concentrate CO2 against a thermodynamic gradient remains unknown4–6. Here we show that in the green alga Chlamydomonas reinhardtii, the combined action of cyclic electron flow and O2 photoreduction—which depend on PGRL1 and flavodiiron proteins, respectively—generate a low luminal pH that is essential for CCM function. We suggest that luminal protons are used downstream of thylakoid bestrophin-like transporters, probably for the conversion of bicarbonate to CO2. We further establish that an electron flow from chloroplast to mitochondria contributes to energizing non-thylakoid inorganic carbon transporters, probably by supplying ATP. We propose an integrated view of the network supplying energy to the CCM, and describe how algal cells distribute energy from photosynthesis to power different CCM processes. These results suggest a route for the transfer of a functional algal CCM to plants to improve crop productivity.
Published: 2022

4. Editorial feature: Meet the PCP editor—Yonghua Li-Beisson

Author: Yonghua Li-Beisson, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0303 health sciences, 03 medical and health sciences, Physiology, [SDV]Life Sciences [q-bio], Cell Biology, Plant Science, General Medicine, 01 natural sciences, 030304 developmental biology, 010606 plant biology & botany
Abstract: International audience; Yonghua Li-Beisson received a B.Sc. from Henan University of Technology, China, and a Ph.D. from the University of Hull (England), where her work highlighted the importance of reducing power for lipid synthesis in oleaginous fungi. She then conducted postdoctoral research at Michigan State University focusing on understanding seed oil biosynthesis as well as dissecting the molecular pathways of lipid polyester synthesis and assembly. Since 2009, Yonghua is a staff scientist at the French Atomic and Alternative Energies Commission in France. Her current work focuses on dissecting lipid metabolism in microalgae, in particular using the model green microalga Chlamydomonas reinhardtii (Li-Beisson et al. 2019). In addition to leading her research team, she is also a director of the lipidomics platform HelioBiotec (https://www.cite-des-energies.fr/biam/plateformes-technologiques/heliobiotec/). Since 2016, Yonghua is a serving editor for Plant and Cell Physiology and handles papers in the area of plant and algal lipid metabolism and physiology
Published: 2021

5. Physiological functions of malate shuttles in plants and algae

Author: Yonghua Li-Beisson, Andreas P.M. Weber, Ousmane Dao, Franziska Kuhnert, Gilles Peltier, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Heinrich Heine Universität Düsseldorf = Heinrich Heine University [Düsseldorf], Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, [SDV]Life Sciences [q-bio], Malates, Plant Science, Biology, Photosynthesis, 01 natural sciences, Malate dehydrogenase, Redox, 03 medical and health sciences, Citrate synthase, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Fatty acid, food and beverages, Metabolic intermediate, NAD, chemistry, Biochemistry, biology.protein, Photorespiration, NAD+ kinase, Oxidation-Reduction, 010606 plant biology & botany
Abstract: Subcellular compartmentalization confers evolutionary advantage to eukaryotic cells but entails the need for efficient interorganelle communication. Malate functions as redox carrier and metabolic intermediate. It can be shuttled across membranes through translocators. The interconversion of malate and oxaloacetate mediated by malate dehydrogenases requires oxidation/reduction of NAD(P)H/NAD(P)+; therefore, malate trafficking serves to transport reducing equivalents and this is termed the ‘malate shuttle’. Although the term 'malate shuttle' was coined more than 50 years ago, novel functions are still emerging. This review highlights recent findings on the functions of malate shuttles in photorespiration, fatty acid β-oxidation, interorganelle signaling and its putative role in CO2-concentrating mechanisms. We compare and contrast knowledge in plants and algae, thereby providing an evolutionary perspective on redox trafficking in photosynthetic eukaryotes.
Published: 2021

6. Alternative electron pathways of photosynthesis drive the algal CO 2 concentrating mechanism

Author: Yonghua Li-Beisson, Gilles Peltier, Ousmane Dao, Adrien Burlacot, Stéphan Cuiné, Pascaline Auroy, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0303 health sciences, biology, Chemiosmosis, Chemistry, [SDV]Life Sciences [q-bio], Chlamydomonas, RuBisCO, Photosynthesis, biology.organism_classification, 01 natural sciences, 03 medical and health sciences, Total inorganic carbon, Mechanism (philosophy), Thylakoid, biology.protein, Biophysics, Chlorophyll fluorescence, 030304 developmental biology, 010606 plant biology & botany
Abstract: Global photosynthesis consumes ten times more CO2 than net anthropogenic emissions, and microalgae account for nearly half of this consumption1. The great efficiency of algal photosynthesis relies on a mechanism concentrating CO2 (CCM) at the catalytic site of the carboxylating enzyme RuBisCO, thus enhancing CO2 fixation2. While many cellular components involved in the transport and sequestration of inorganic carbon (Ci) have been uncovered3,4, the way microalgae supply energy to concentrate CO2 against a thermodynamic gradient remains elusive4-6. Here, by monitoring dissolved CO2 consumption, unidirectional O2 exchange and the chlorophyll fluorescence parameter NPQ in the green alga Chlamydomonas, we show that the complementary effects of cyclic electron flow and O2 photoreduction, respectively mediated by PGRL1 and flavodiiron proteins, generate the proton motive force (pmf) required by Ci transport across thylakoid membranes. We demonstrate that the trans-thylakoid pmf is used by bestrophin-like Ci transporters and further establish that a chloroplast-to-mitochondria electron flow contributes to energize non-thylakoid Ci transporters, most likely by supplying ATP. We propose an integrated view of the CCM energy supply network, describing how algal cells distribute photosynthesis energy to power different Ci transporters, thus paving the way to the transfer of a functional algal CCM in plants towards improving crop productivity.One sentence summaryPhotosynthetic alternative electron flows and mitochondrial respiration drive the algal CO2 concentrating mechanism
Published: 2021

7. Long‐chain acyl‐CoA synthetases activate fatty acids for lipid synthesis, remodeling and energy production in Chlamydomonas

Author: Fan Bai, Jin Liu, Yonghua Li-Beisson, Lihua Yu, Jianan Shi, Peking University [Beijing], Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), This work is partially supported by grants from the National Natural Science Foundation of China (31770048) and the National Key R&D Program of China (2018YFA0902500), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, Physiology, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, Plant Science, 7. Clean energy, 01 natural sciences, Ligases, 03 medical and health sciences, Lipid droplet, Coenzyme A, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, Catabolism, Chlamydomonas, Fatty Acids, Fatty acid, Lipid metabolism, biology.organism_classification, Chloroplast, Enzyme, chemistry, Biochemistry, 010606 plant biology & botany
Abstract: International audience; Long-chain acyl-CoA synthetases (LACSs) play many roles in mammals, yeasts and plants, but knowledge on their functions in microalgae remains fragmented. Here via genetic, biochemical and physiological analyses, we unraveled the function and roles of LACSs in the model microalga Chlamydomonas reinhardtii. In vitro assays on purified recombinant proteins revealed that CrLACS1, CrLACS2 and CrLACS3 all exhibited bona fide LACS activities toward a broad range of free fatty acids. The Chlamydomonas mutants compromised in CrLACS1, CrLACS2 or CrLACS3 did not show any obvious phenotypes in lipid content or growth under nitrogen (N)-replete condition. But under N-deprivation, CrLACS1 or CrLACS2 suppression resulted in c. 50% less oil, yet with a higher amount of chloroplast lipids. By contrast, CrLACS3 suppression impaired oil remobilization and cell growth severely during N-recovery, supporting its role in fatty acid β-oxidation to provide energy and carbon sources for regrowth. Transcriptomics analysis suggested that the observed lipid phenotypes are likely not due to transcriptional reprogramming but rather a shift in metabolic adjustment. Taken together, this study provided solid experimental evidence for essential roles of the three Chlamydomonas LACS enzymes in lipid synthesis, remodeling and catabolism, and highlighted the importance of lipid homeostasis in cell growth under nutrient fluctuations.
Published: 2021

8. CO$_2$ supply modulates lipid remodelling, photosynthetic and respiratory activities in $Chlorella$ species

Author: Michela Cecchin, Matteo Paloschi, Matteo Ballottari, Giovanni Busnardo, Yonghua Li-Beisson, Lutz Wobbe, Stefano Cazzaniga, Stéphan Cuiné, University of Verona (UNIVR), Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Center for Biotechnology (CeBiTec), Universität Bielefeld = Bielefeld University, European Project: 679814,H2020,ERC-2015-STG,SOLENALGAE(2016), Università degli studi di Verona = University of Verona (UNIVR), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, 0301 basic medicine, Chloroplasts, Physiology, [SDV]Life Sciences [q-bio], Chlorella vulgaris, Cell Respiration, Chlamydomonas reinhardtii, Plant Science, Chlorophyta, Photosynthesis, 01 natural sciences, carbon assimilation, lipids, 03 medical and health sciences, Algae, triacylglycerols, chlorella, Chlorella sorokiniana, photosynthesis, biology, Chemistry, microalgae, Carbon Dioxide, biology.organism_classification, Lipid Metabolism, Mitochondria, Chloroplast, Chlorella, 030104 developmental biology, Biochemistry, 13. Climate action, Oxidation-Reduction, respiration, 010606 plant biology & botany
Abstract: Microalgae represent a potential solution to reduce CO2 emission exploiting their photosynthetic activity. Here, the physiologic and metabolic responses at the base of CO2 assimilation were investigated in conditions of high or low CO2 availability in two of the most promising algae species for industrial cultivation, Chlorella sorokiniana and Chlorella vulgaris. In both species, high CO2 availability increased biomass accumulation with specific increase of triacylglycerols in C. vulgaris and polar lipids and proteins in C. sorokiniana. Moreover, high CO2 availability caused only in C. vulgaris a reduced NAD(P)H/NADP+ ratio and reduced mitochondrial respiration, suggesting a CO2 dependent increase of reducing power consumption in the chloroplast, which in turn influences the redox state of the mitochondria. Several rearrangements of the photosynthetic machinery were observed in both species, differing from those described for the model organism Chlamydomonas reinhardtii, where adaptation to carbon availability is mainly controlled by the translational repressor NAB1. NAB1 homologous protein could be identified only in C. vulgaris but lacked the regulation mechanisms previously described in C. reinhardtii. Acclimation strategies to cope with a fluctuating inorganic carbon supply are thus diverse among green microalgae, and these results suggest new biotechnological strategies to boost CO2 fixation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Published: 2021

9. The disassembly of lipid droplets in Chlamydomonas

Author: Byung-Ho Kang, Pengfei Wang, Fantao Kong, Youngsook Lee, Yonghua Li-Beisson, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, Physiology, Membrane lipids, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, Plant Science, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Lipid droplet, Organelle, Triglycerides, ComputingMilieux_MISCELLANEOUS, Phosphatidylethanolamine, biology, Chlamydomonas, Lipase, Lipid Droplets, Peroxisome, biology.organism_classification, Lipid Metabolism, Cell biology, 030104 developmental biology, chemistry, Biogenesis, 010606 plant biology & botany
Abstract: Lipid droplets (LDs) are ubiquitous and specialized organelles in eukaryotic cells. Consisting of a triacylglycerol core surrounded by a monolayer of membrane lipids, LDs are decorated with proteins and have myriad functions, from carbon/energy storage to membrane lipid remodeling and signal transduction. The biogenesis and turnover of LDs are therefore tightly coordinated with cellular metabolic needs in a fluctuating environment. Lipid droplet turnover requires remodeling of the protein coat, lipolysis, autophagy and fatty acid β-oxidation. Several key components of these processes have been identified in Chlamydomonas (Chlamydomonas reinhardtii), including the major lipid droplet protein, a CXC-domain containing regulatory protein, the phosphatidylethanolamine-binding DTH1 (DELAYED IN TAG HYDROLYSIS1), two lipases and two enzymes involved in fatty acid β-oxidation. Here, we review LD turnover and discuss its physiological significance in Chlamydomonas, a major model green microalga in research on algal oil.
Published: 2021

10. Mechanism and dynamics of fatty acid photodecarboxylase

Author: Sébastien Boutet, Catherine Berthomieu, Laura Antonucci, A. Gorel, Manuel Joffre, Marco Cammarata, A. Benachir, Sergio Carbajo, Solène L. Y. Moulin, Martin Weik, Michel Sliwa, Stephane Cuine, Yonghua Li-Beisson, Nicolas Coquelle, Didier Nurizzo, P. Samire, Jacques-Philippe Colletier, Alexey Aleksandrov, Robert L. Shoeman, Guillaume Gotthard, Antoine Royant, Marten H. Vos, Bo Zhuang, M. Hilpert, Adeline Bonvalet, Ilme Schlichting, Xavier Solinas, Martin Byrdin, Pascal Arnoux, Gilles Peltier, Pierre Legrand, F. Beisson, Klaus Brettel, R. Hienerwadel, Thomas R. M. Barends, R.B. Doak, Lutz Foucar, T. Domratcheva, Damien Sorigué, Marco Kloos, Stéphanie Blangy, Giorgio Schirò, Kyprianos Hadjidemetriou, Bertrand Légeret, Thomas J. Lane, Marie Luise Grünbein, Pavel Müller, Elisabeth Hartmann, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), European Synchroton Radiation Facility [Grenoble] (ESRF), Laboratoire d'Optique et Biosciences (LOB), École polytechnique (X)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), SLAC National Accelerator Laboratory (SLAC), Stanford University, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Medizinische Forschung, Max-Planck-Gesellschaft, Luminy Génétique et Biophysique des Plantes (LGBP), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Interactions Protéine Métal (IPM), Department of Chemistry, Lomonosov Moscow State University, Lomonosov Moscow State University (MSU), Microbiologie Environnementale et Moléculaire (MEM), STepLADDER (724362), European Research Council, 724362, European Research Council, SNAPsHOTs, Agence Nationale de la Recherche, Photoalkane, Agence Nationale de la Recherche, SignalBioNRJ, Agence Nationale de la Recherche, BioXFEL, Agence Nationale de la Recherche, Ministère de l’Education Nationale, de l’Enseignement Supérieur et de la Recherche, ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-18-CE11-0021,SNAPsHOTs,Dynamique structurale de l'acide gras photodécarboxylase(2018), ANR-18-CE43-0008,PHOTOALKANE,Production biosourcée d'hydrocarbures basée sur une nouvelle photoenzyme(2018), ANR-15-CE32-0004,BioXFEL,Caractérisation d'états intermédiaires de protéines fluorescentes en utilisant des lasers à électrons libres X et les spectroscopies UV-visible et infrarouge ultra-rapides(2015), European Project: 724362,STePLADDER - H2020-EU.1.1., Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ILL, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Vos, Marten, Infrastructure Française pour la Biologie Structurale Intégrée - - FRISBI2010 - ANR-10-INBS-0005 - INBS - VALID, APPEL À PROJETS GÉNÉRIQUE 2018 - Dynamique structurale de l'acide gras photodécarboxylase - - SNAPsHOTs2018 - ANR-18-CE11-0021 - AAPG2018 - VALID, APPEL À PROJETS GÉNÉRIQUE 2018 - Production biosourcée d'hydrocarbures basée sur une nouvelle photoenzyme - - PHOTOALKANE2018 - ANR-18-CE43-0008 - AAPG2018 - VALID, Caractérisation d'états intermédiaires de protéines fluorescentes en utilisant des lasers à électrons libres X et les spectroscopies UV-visible et infrarouge ultra-rapides - - BioXFEL2015 - ANR-15-CE32-0004 - AAPG2015 - VALID, and Solving The Pathway of LADDERane biosynthesis - STePLADDER - H2020-EU.1.1. - 724362 - INCOMING
Subjects: Models, Molecular, Light, Carboxy-Lyases, Protein Conformation, Decarboxylation, Chlorella, Reaction intermediate, Flavin group, Crystallography, X-Ray, 010402 general chemistry, Photochemistry, 01 natural sciences, [PHYS] Physics [physics], Electron Transport, 03 medical and health sciences, Catalytic Domain, Alkanes, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Amino Acids, Alkyl, 030304 developmental biology, chemistry.chemical_classification, [PHYS]Physics [physics], Photons, 0303 health sciences, Multidisciplinary, Algal Proteins, Fatty Acids, Temperature, Fatty acid, Substrate (chemistry), Hydrogen Bonding, Carbon Dioxide, Chromophore, Electron transport chain, 0104 chemical sciences, Bicarbonates, Amino Acid Substitution, chemistry, 13. Climate action, Biocatalysis, Flavin-Adenine Dinucleotide, Mutant Proteins, Oxidation-Reduction
Abstract: Light makes light work of fatty acids Photosynthetic organisms are notable for their ability to capture light energy and use it to power biosynthesis. Some algae have gone a step beyond photosynthesis and can use light to initiate enzymatic photodecarboxylation of fatty acids, producing long-chain hydrocarbons. To understand this transformation, Sorigué et al. brought to bear an array of structural, computational, and spectroscopic techniques and fully characterized the catalytic cycle of the enzyme. These experiments are consistent with a mechanism starting with electron transfer from the fatty acid to a photoexcited oxidized flavin cofactor. Decarboxylation yields an alkyl radical, which is then reduced by back electron transfer and protonation rather than hydrogen atom transfer. The wealth of experimental data explains how algae harness light energy to produce alka(e)nes and provides an appealing model system for understanding enzyme-catalyzed photochemistry more generally. Science , this issue p. eabd5687
Published: 2021

11. Fatty acid photodecarboxylase is an ancient photoenzyme that forms hydrocarbons in the thylakoids of algae

Author: Bertrand Légeret, Damien Sorigué, Magali Floriani, Adrien Burlacot, Stéphan Cuiné, Audrey Beyly-Adriano, Stéphanie Blangy, Fred Beisson, Poutoum-Palakiyem Samire, Solène L. Y. Moulin, Gilles Peltier, Yonghua Li-Beisson, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'écotoxicologie des radionucléides (PRP-ENV/SERIS/LECO), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'écotoxicologie des radionucléides (IRSN/PRP-ENV/SERIS/LECO), Service de Recherche et d'Expertise sur les Risques environnementaux (IRSN/PRP-ENV/SERIS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), and ANR-18-CE43-0008,PHOTOALKANE,Production biosourcée d'hydrocarbures basée sur une nouvelle photoenzyme(2018)
Subjects: 0106 biological sciences, congenital, hereditary, and neonatal diseases and abnormalities, Genotype, Light, Carboxy-Lyases, Physiology, Chlamydomonas reinhardtii, Plant Science, Genes, Plant, Thylakoids, 01 natural sciences, 03 medical and health sciences, Algae, Gene Expression Regulation, Plant, Microalgae, Genetics, Cold acclimation, Plastid, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], neoplasms, Research Articles, 030304 developmental biology, 0303 health sciences, biology, Endosymbiosis, Chemistry, Fatty Acids, Genetic Variation, Ectocarpus, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Photochemical Processes, biology.organism_classification, digestive system diseases, Light intensity, Biochemistry, Mutation, Nannochloropsis, 010606 plant biology & botany
Abstract: Fatty acid photodecarboxylase (FAP) is one of the few enzymes that require light for their catalytic cycle (photoenzymes). FAP was first identified in the microalga Chlorella variabilis NC64A, and belongs to an algae-specific subgroup of the glucose–methanol–choline oxidoreductase family. While the FAP from C. variabilis and its Chlamydomonas reinhardtii homolog CrFAP have demonstrated in vitro activities, their activities and physiological functions have not been studied in vivo. Furthermore, the conservation of FAP activity beyond green microalgae remains hypothetical. Here, using a C. reinhardtii FAP knockout line (fap), we showed that CrFAP is responsible for the formation of 7-heptadecene, the only hydrocarbon of this alga. We further showed that CrFAP was predominantly membrane-associated and that >90% of 7-heptadecene was recovered in the thylakoid fraction. In the fap mutant, photosynthetic activity was not affected under standard growth conditions, but was reduced after cold acclimation when light intensity varied. A phylogenetic analysis that included sequences from Tara Ocean identified almost 200 putative FAPs and indicated that FAP was acquired early after primary endosymbiosis. Within Bikonta, FAP was retained in secondary photosynthetic endosymbiosis lineages but absent from those that lost the plastid. Characterization of recombinant FAPs from various algal genera (Nannochloropsis, Ectocarpus, Galdieria, Chondrus) provided experimental evidence that FAP photochemical activity was present in red and brown algae, and was not limited to unicellular species. These results thus indicate that FAP was conserved during the evolution of most algal lineages where photosynthesis was retained, and suggest that its function is linked to photosynthetic membranes.
Published: 2021

12. The NanDeSyn database for $Nannochloropsis$ systems and synthetic biology

Author: Jian Xu, Yonghua Li-Beisson, Jong-Min Lim, Young Uk Kim, Byeong-ryool Jeong, Nam Kyu Kang, Yanhai Gong, Guanpin Yang, Kehou Pan, Li Wei, Yantao Li, Yi Xin, Qiang Hu, Wuxin You, Hee-Mock Oh, Yong K Chang, Zengbin Wang, Won-Joong Jeong, Eric Poliner, Youn-Il Park, Suk-Won Jeong, Eva M. Farré, Chen Shen, Qintao Wang, Ansgar Poetsch, University of Chinese Academy of Sciences [Beijing] (UCAS), Qingdao National Laboratory for Marine Science and Technology, Department of Electrical Engineering [Korea Advanced Institute of Science and Technology] (KAIST), Korea Advanced Institute of Science and Technology (KAIST), Chinese Academy of Sciences [Beijing] (CAS), Ruhr-Universität Bochum [Bochum], Korea Research Institute of Bioscience & Biotechnology (KRIBB), Chungnam National University (CNU), Ocean University of China (OUC), MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Michigan State University System, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Maryland Center for Environmental Science (UMCES), University of Maryland System, Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Epigenomics, Proteomics, 0106 biological sciences, [SDV]Life Sciences [q-bio], Genomics, Plant Science, Genome browser, Biology, computer.software_genre, 01 natural sciences, Genome, 03 medical and health sciences, Synthetic biology, RNA, Small Cytoplasmic, Microalgae, Genetics, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Synteny, Internet, 0303 health sciences, Database, Cell Biology, Gene Annotation, biology.organism_classification, Databases as Topic, Synthetic Biology, Transcriptome, computer, Functional genomics, Metabolic Networks and Pathways, Nannochloropsis, 010606 plant biology & botany
Abstract: International audience; Nannochloropsis species, unicellular industrial oleaginous microalgae, are model organisms for microalgal systems and synthetic biology. To facilitate community-based annotation and mining of the rapidly accumulating functional genomics resources, we have initiated an international consortium and present a comprehensive multi-omics resource database named Nannochloropsis Design and Synthesis (NanDeSyn; http://nandesyn.single-cell.cn). Via the Tripal toolkit, it features user-friendly interfaces hosting genomic resources with gene annotations and transcriptomic and proteomic data for six Nannochloropsis species, including two updated genomes of Nannochloropsis oceanica IMET1 and Nannochloropsis salina CCMP1776. Toolboxes for search, Blast, synteny view, enrichment analysis, metabolic pathway analysis, a genome browser, etc. are also included. In addition, functional validation of genes is indicated based on phenotypes of mutants and relevant bibliography. Furthermore, epigenomic resources are also incorporated, especially for sequencing of small RNAs including microRNAs and circular RNAs. Such comprehensive and integrated landscapes of Nannochloropsis genomics and epigenomics will promote and accelerate community efforts in systems and synthetic biology of these industrially important microalgae.
Published: 2020

13. ppGpp influences protein protection, growth and photosynthesis in Phaeodactylum tricornutum

Author: Benjamin Field, Benoît Menand, Yonghua Li-Beisson, Sylvie Citerne, Stéphan Cuiné, Régine Lebrun, Carine Puppo, Brigitte Gontero, Luisana Avilan, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Plateforme Protéomique [Marseille], Institut de Microbiologie de la Méditerranée (IMM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Luminy Génétique et Biophysique des Plantes (LGBP), Department of Metabolic Biology, John Innes Centre [Norwich], AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Environnement, Bioénergie, Microalgues et Plantes (EBMP), IJPB Plant Observatory technological platform, ANR-15-CE05-0021,SIGNAUXBIONRJ,Manipulation des voies de signalisation de l'énergie afin d'améliorer la production de .lipides chez les eucaryotes photosynthétiques(2015), ANR-17-EURE-0007,SPS-GSR,Ecole Universitaire de Recherche de Sciences des Plantes de Paris-Saclay(2017), ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, Chloroplasts, Physiology, lipid droplets, proteome, [SDV]Life Sciences [q-bio], Guanosine, Guanosine Tetraphosphate, Plant Science, Photosynthesis, 01 natural sciences, Phaeodactylum tricornutum, diatoms, 03 medical and health sciences, chemistry.chemical_compound, ppGpp, chloroplast, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Arabidopsis, Gene expression, heterocyclic compounds, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Plastid, 030304 developmental biology, 0303 health sciences, photosynthesis, Full Paper, biology, Chemistry, Research, Guanosine Pentaphosphate, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Full Papers, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, biology.organism_classification, equipment and supplies, Cell biology, Chloroplast, 030104 developmental biology, [SDE]Environmental Sciences, bacteria, Function (biology), 010606 plant biology & botany
Abstract: SummaryChloroplasts retain elements of a bacterial stress response pathway that is mediated by the signalling nucleotides guanosine penta- and tetraphosphate, or (p)ppGpp. In the model flowering plant Arabidopsis, ppGpp acts as a potent regulator of plastid gene expression and influences photosynthesis, plant growth and development. However, little is known about ppGpp metabolism or its evolution in other photosynthetic eukaryotes.Here, we studied the function of ppGpp in the diatom P. tricornutum using transgenic lines containing an inducible system for ppGpp accumulation. We used these lines to investigate the effects of ppGpp on growth, photosynthesis, lipid metabolism and protein expression.We demonstrate that ppGpp accumulation reduces photosynthetic capacity and promotes a quiescent-like state with reduced proliferation and ageing. Strikingly, using non-targeted proteomics, we discovered that ppGpp accumulation also leads to the coordinated upregulation of a protein protection response in multiple cellular compartments.Our findings highlight the importance of ppGpp as a fundamental regulator of chloroplast function across different domains of life, and lead to new questions about the molecular mechanisms and roles of (p)ppGpp signalling in photosynthetic eukaryotes.
Published: 2020

14. The phosphatidylethanolamine-binding protein DTH1 mediates degradation of lipid droplets in Chlamydomonas reinhardtii

Author: Youngsook Lee, Peng Gao, Audrey Beyly-Adriano, Byung-Ho Kang, Sunghoon Jang, Jihyeon Lee, Yonghua Li-Beisson, Caroline Cagnon, Fantao Kong, Yasuyo Yamaoka, Pohang University of Science and Technology (POSTECH), Dalian University of Technology, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), The Chinese University of Hong Kong [Hong Kong], ANR-12-BIME-0001,DIESALG,Production de biodiesel par microalgues(2012), ANR-15-CE05-0021,SIGNAUXBIONRJ,Manipulation des voies de signalisation de l'énergie afin d'améliorer la production de .lipides chez les eucaryotes photosynthétiques(2015), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, Phosphatidylethanolamine, Multidisciplinary, biology, Chemistry, [SDV]Life Sciences [q-bio], Mutant, Chlamydomonas, Phospholipid, Chlamydomonas reinhardtii, biology.organism_classification, 01 natural sciences, Cell biology, Apolipoproteins E, 03 medical and health sciences, Phosphatidylethanolamine Binding Protein, chemistry.chemical_compound, 030104 developmental biology, Lipid droplet, 010606 plant biology & botany
Abstract: International audience; Lipid droplets (LDs) are intracellular organelles found in a wide range of organisms and play important roles in stress tolerance. During nitrogen (N) starvation, Chlamydomonas reinhardtii stores large amounts of triacylglycerols (TAGs) inside LDs. When N is resupplied, the LDs disappear and the TAGs are degraded, presumably providing carbon and energy for regrowth. The mechanism by which cells degrade LDs is poorly understood. Here, we isolated a mutant ( dth1-1 , Delayed in TAG Hydrolysis 1) in which TAG degradation during recovery from N starvation was compromised. Consequently, the dth1-1 mutant grew poorly compared to its parental line during N recovery. Two additional independent loss-of-function mutants ( dth1-2 and dth1-3 ) also exhibited delayed TAG remobilization. DTH1 transcript levels increased sevenfold upon N resupply, and DTH1 protein was localized to LDs. DTH1 contains a putative lipid-binding domain (DTH1$^{LBD}$) with alpha helices predicted to be structurally similar to those in apolipoproteins E and A–I. Recombinant DTH1$^{LBD}$ bound specifically to phosphatidylethanolamine (PE), a major phospholipid coating the LD surface. Overexpression of DTH1$^{LBD}$ in Chlamydomonas phenocopied the dth1 mutant’s defective TAG degradation, suggesting that the function of DTH1 depends on its ability to bind PE. Together, our results demonstrate that the lipid-binding DTH1 plays an essential role in LD degradation and provide insight into the molecular mechanism of protein anchorage to LDs at the LD surface in photosynthetic cells.
Published: 2020

15. Plant unusual fatty acids: learning from the less common

Author: Yonghua Li-Beisson, Edgar B. Cahoon, University of Nebraska System, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0106 biological sciences, 0301 basic medicine, [SDV]Life Sciences [q-bio], Plant Science, Cutin, Biology, 01 natural sciences, Metabolic engineering, 03 medical and health sciences, chemistry.chemical_compound, Biosynthesis, Plant Oils, 2. Zero hunger, chemistry.chemical_classification, Fatty Acids, food and beverages, Metabolism, Plants, 030104 developmental biology, Enzyme, Metabolic Engineering, chemistry, Biochemistry, Seeds, Fatty acid elongation, Function (biology), 010606 plant biology & botany
Abstract: International audience; The plant kingdom contains an abundance of structurally diverse fatty acids referred to as unusual fatty acids. Unusual fatty acids on plant surfaces can form polyesters that contribute to the function of cutin as a barrier for water loss and pathogen protection. Unusual fatty acids are also found as abundant components of seed oils of selected species and often confer desirable properties for industrial and nutritional applications. Here, we review recent findings on the biosynthesis and metabolism of unusual fatty acids in cutin and seed oils and use of this information for enzyme structure-function studies and seed oil metabolic engineering. We also highlight the recent discovery of unusual fatty acids that are formed from a previously undescribed variation of fatty acid elongation.
Published: 2020

16. Membrane inlet mass spectrometry at the crossroads of photosynthesis, biofuel and climate research

Author: Adrien Burlacot, Gilles Peltier, Yonghua Li-Beisson, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0106 biological sciences, geography, geography.geographical_feature_category, Physiology, Climate, Plant Science, Inlet, Photosynthesis, Mass spectrometry, 7. Clean energy, 01 natural sciences, Mass Spectrometry, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, Membrane, 13. Climate action, Biofuel, Biofuels, Environmental chemistry, Genetics, Letters, 010606 plant biology & botany
Abstract: International audience; Microalgae are continuously shaping Earth’s atmosphere through oxygenic photosynthesis, and nowadays, half of the photosynthesis is attributed to microbial photosynthesis (Field et al., 1998; Behrenfeld et al., 2005). While algal photosynthesis contributes to offsetting the CO2 footprint, it also produces nitric oxide (N2O), a potent greenhouse gas. In some ecological niches microalgae can produce hydrogen (H2), a promising energy carrier; therefore microalgae are actively explored for their potential as a platform for production of renewable energy. Measuring gas exchange between algae and the atmosphere, and understanding biological mechanisms underlying photosynthetic CO2 capture, and O2, H2, or N2O production, holds great promise—not only to better evaluate the reciprocal effects of global changes on oceanic carbon sinks, but also to explore the limits of biomass and biofuel productivity of algae. Membrane inlet mass spectrometry (MIMS) was initially developed to measure O2 exchange between algal cells and the surrounding liquid medium (Hoch and Kok, 1963), and its use has since been extended to other gases including H2 and more recently, N2O (Burlacot et al., 2020). Here we review recent breakthroughs allowed by MIMS in dissecting molecular mechanisms of gas exchange in microalgae (Fig. 1) and provide perspectives on how MIMS will be crucial to address future challenges in algal research.
Published: 2020

17. Continuous photoproduction of hydrocarbon drop-in fuel by microbial cell factories

Author: Yonghua Li-Beisson, Gilles Peltier, Stéphanie Blangy, Adrien Burlacot, Damien Sorigué, Fred Beisson, Pascaline Auroy, Bertrand Légeret, Solène L. Y. Moulin, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Programme CEA DRF Impulsion Invention, Alcasun, HelioBiotec platform funded by the EU, the région PACA, the French Ministry of Research, and the CEA, ANR-18-CE43-0008,PHOTOALKANE,Production biosourcée d'hydrocarbures basée sur une nouvelle photoenzyme(2018), Burlacot, Adrien, APPEL À PROJETS GÉNÉRIQUE 2018 - Production biosourcée d'hydrocarbures basée sur une nouvelle photoenzyme - - PHOTOALKANE2018 - ANR-18-CE43-0008 - AAPG2018 - VALID, Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Light, lcsh:Medicine, 01 natural sciences, 7. Clean energy, Continuous production, Article, 03 medical and health sciences, Key point, Thioesterase, Continuous release, Escherichia coli, Microalgae, lcsh:Science, chemistry.chemical_classification, Multidisciplinary, Drop (liquid), lcsh:R, Fatty Acids, Fatty acid, Pulp and paper industry, Hydrocarbons, Enzymes, [SDV.BIO] Life Sciences [q-bio]/Biotechnology, 030104 developmental biology, Hydrocarbon, chemistry, Biofuels, lcsh:Q, Volatility (chemistry), Metabolic engineering, 010606 plant biology & botany
Abstract: Use of microbes to produce liquid transportation fuels is not yet economically viable. A key point to reduce production costs is the design a cell factory that combines the continuous production of drop-in fuel molecules with the ability to recover products from the cell culture at low cost. Medium-chain hydrocarbons seem ideal targets because they can be produced from abundant fatty acids and, due to their volatility, can be easily collected in gas phase. However, pathways used to produce hydrocarbons from fatty acids require two steps, low efficient enzymes and/or complex electron donors. Recently, a new hydrocarbon-forming route involving a single enzyme called fatty acid photodecarboxylase (FAP) was discovered in microalgae. Here, we show that in illuminated E. coli cultures coexpression of FAP and a medium-chain fatty acid thioesterase results in continuous release of volatile hydrocarbons. Maximum hydrocarbon productivity was reached under low/medium light while higher irradiance resulted in decreased amounts of FAP. It was also found that the production rate of hydrocarbons was constant for at least 5 days and that 30% of total hydrocarbons could be collected in the gas phase of the culture. This work thus demonstrates that the photochemistry of the FAP can be harnessed to design a simple cell factory that continuously produces hydrocarbons easy to recover and in pure form.
Published: 2019

18. Chlorella vulgaris genome assembly and annotation reveals the molecular basis for metabolic acclimation to high light conditions

Author: Massimo Delledonne, Laura Girolomoni, Stéphan Cuiné, Luca Marcolungo, Marzia Rossato, Michela Cecchin, Matteo Ballottari, Yonghua Li-Beisson, Emanuela Cosentino, Università degli studi di Verona = University of Verona (UNIVR), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Verona (UNIVR), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Light, Acclimatization, [SDV]Life Sciences [q-bio], Sequence assembly, Plant Science, 01 natural sciences, 7. Clean energy, Genome, Genome editing, Gene Expression Regulation, Plant, Biomass, Phylogeny, ComputingMilieux_MISCELLANEOUS, 2. Zero hunger, fatty acid synthase, 0303 health sciences, microalgae, Fatty Acids, carotenoids, Meiosis, motility, Biochemistry, biofuels, carotenoids, Chlorella vulgaris,horizontal gene transfer, lipids, microalgae, motility, fatty acid synthase, horizontal gene transfer, Chlorella vulgaris, Genome, Plant, Biotechnology, Resource, Mitochondrial DNA, Nuclear gene, Gene Transfer, Horizontal, Biology, DNA sequencing, lipids, 03 medical and health sciences, Genetics, Gene, Triglycerides, 030304 developmental biology, Base Sequence, Molecular Sequence Annotation, Cell Biology, biofuels, Biosynthetic Pathways, Gene Ontology, Genome, Mitochondrial, Fatty Acid Synthases, Transcriptome, 010606 plant biology & botany
Abstract: Summary Chlorella vulgaris is a fast‐growing fresh‐water microalga cultivated on the industrial scale for applications ranging from food to biofuel production. To advance our understanding of its biology and to establish genetics tools for biotechnological manipulation, we sequenced the nuclear and organelle genomes of Chlorella vulgaris 211/11P by combining next generation sequencing and optical mapping of isolated DNA molecules. This hybrid approach allowed us to assemble the nuclear genome in 14 pseudo‐molecules with an N50 of 2.8 Mb and 98.9% of scaffolded genome. The integration of RNA‐seq data obtained at two different irradiances of growth (high light, HL versus low light, LL) enabled us to identify 10 724 nuclear genes, coding for 11 082 transcripts. Moreover, 121 and 48 genes, respectively, were found in the chloroplast and mitochondrial genome. Functional annotation and expression analysis of nuclear, chloroplast and mitochondrial genome sequences revealed particular features of Chlorella vulgaris. Evidence of horizontal gene transfers from chloroplast to mitochondrial genome was observed. Furthermore, comparative transcriptomic analyses of LL versus HL provided insights into the molecular basis for metabolic rearrangement under HL versus LL conditions leading to enhanced de novo fatty acid biosynthesis and triacylglycerol accumulation. The occurrence of a cytosolic fatty acid biosynthetic pathway could be predicted and its upregulation upon HL exposure was observed, consistent with the increased lipid amount under HL conditions. These data provide a rich genetic resource for future genome editing studies, and potential targets for biotechnological manipulation of Chlorella vulgaris or other microalgae species to improve biomass and lipid productivity., Significance Statement Microalgae cultivation is one of the most promising strategies for novel food or biofuel production. High‐quality genome information is required for understanding algae biology, for their biotechnological optimization and for genome editing applications. Here, the genome of Chlorella vulgaris, one of the green algae species with the highest productivity potential, is presented and functionally annotated, revealing notable features among Chlorophyta.
Published: 2019

19. Plant and algal lipids set sail for new horizons

Author: Yonghua Li-Beisson, Hajime Wada, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Graduate School of Arts and Sciences, The University of Tokyo, ANR-15-CE05-0021,SIGNAUXBIONRJ,Manipulation des voies de signalisation de l'énergie afin d'améliorer la production de .lipides chez les eucaryotes photosynthétiques(2015), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diatoms, New horizons, biology, Physiology, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, Cell Biology, Plant Science, General Medicine, Plant Lipids, ISPL 2018 meeting, Plants, Lipid Metabolism, biology.organism_classification, Lipids, Bryopsida, Set (abstract data type), Algal Lipids, Editorial, Botany, Plant Physiological Phenomena, Stramenopiles, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2019

20. LIP4 Is Involved in Triacylglycerol Degradation in $Chlamydomonas\ reinhardtii$

Author: Christoph Benning, Jaruswan Warakanont, Yonghua Li-Beisson, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Kasetsart University - KU (THAILAND), Kasetsart University (KU), Michigan State University [East Lansing], Michigan State University System, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, 0301 basic medicine, Physiology, Membrane lipids, [SDV]Life Sciences [q-bio], Mutant, Triacylglycerol lipase, Arabidopsis, Chlamydomonas reinhardtii, Plant Science, 01 natural sciences, 7. Clean energy, 03 medical and health sciences, chemistry.chemical_compound, Glycerol, Lipase, SUGAR DEPENDENT1, Phylogeny, Triglycerides, chemistry.chemical_classification, biology, Arabidopsis Proteins, Algal Proteins, lipid catabolism, Cell Biology, General Medicine, biology.organism_classification, triacylglycerol lipase, Amino acid, 030104 developmental biology, Enzyme, Biochemistry, chemistry, TAG remobilization, biology.protein, N recovery, Carboxylic Ester Hydrolases, $Chlamydomonas\ reinhardtii$, 010606 plant biology & botany
Abstract: International audience; Degradation of the storage compound triacylglycerol (TAG) is a crucial process in response to environmental stimuli. Failing to respond properly may be detrimental for survival. In microalgae, this process is important for re-growth when conditions become favorable after cells have experienced stresses. Mobilization of TAG is initiated by actions of lipases causing the release of glycerol and free fatty acids, which can be further broken down for energy production or recycled to synthesize membrane lipids. Although key enzymes in the process, TAG lipases remain to be characterized in the model green alga $Chlamydomonas\ reinhardtii$. Here we describe the functional analysis of a putative TAG lipase, i.e. CrLIP4, which shares 44% amino acid identity with the major TAG lipase in $Arabidopsis$ (SUGAR DEPENDENT1- SDP1). The $CrLIP4$ transcript level was down regulated during nitrogen deprivation (ND) when TAG accumulates, but was upregulated during nitrogen recovery (NR) when TAG wasdegraded. Both artificial microRNA knockdown and insertional knockout mutants showed a delay in TAG mobilization during NR. The difference in TAG degradation was more pronounced when the cultures were incubated without acetate in the dark. Furthermore, the $crlip4$ knock-out mutant over-accumulated TAG during optimal growth conditions. Taken together, the results suggest to us that CrLIP4 likely acts as a TAG lipase and plays a major role in TAG homeostasis in $Chlamydomonas$.
Published: 2019

21. The bZIP1 Transcription Factor Regulates Lipid Remodeling and Contributes to ER Stress Management in $Chlamydomonas\ reinhardtii$

Author: Bertrand Legeret, Takashi Yamano, Bae Young Choi, Youngsook Lee, Sunghoon Jang, Hideya Fukuzawa, Masataka Kajikawa, Seung-Jun Shin, Yonghua Li-Beisson, Yasuyo Yamaoka, Fantao Kong, Hanul Kim, Pohang University of Science and Technology (POSTECH), Graduate School of Biostudies, Kyoto University [Kyoto], Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), Kyoto University, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, 0301 basic medicine, Linolenic Acids, [SDV]Life Sciences [q-bio], Mutant, Chlamydomonas reinhardtii, Pinolenic acid, Plant Science, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Endoplasmic Reticulum, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, RNA, Messenger, Transcription factor, Research Articles, Alleles, Triglycerides, Plant Proteins, Cell Nucleus, biology, Endoplasmic reticulum, Tunicamycin, Chlamydomonas, Cell Biology, biology.organism_classification, Endoplasmic Reticulum Stress, Lipid Metabolism, Cell biology, 030104 developmental biology, Basic-Leucine Zipper Transcription Factors, chemistry, RNA, Plant, Mutation, Unfolded protein response, Unfolded Protein Response, 010606 plant biology & botany
Abstract: International audience; Endoplasmic reticulum (ER) stress is caused by the stress-induced accumulation of unfolded proteins in the ER. Here, we identified proteins and lipids that function downstream of the ER stress sensor INOSITOL-REQUIRING ENZYME1 (CrIRE1) that contributes to ER stress tolerance in Chlamydomonas ($Chlamydomonas\ reinhardtii$). Treatment with the ER stress inducer tunicamycin resulted in the splicing of a 32-nucleotide fragment of a basic leucine zipper 1 (bZIP1) transcription factor ($CrbZIP1$) mRNA by CrIRE1 that, in turn, resulted in the loss of the transmembrane domain in CrbZIP1, and the translocation of CrbZIP1 from the ER to the nucleus. Mutants deficient in CrbZIP1 failed to induce the expression of the unfolded protein response genes and grew poorly under ER stress. Levels of diacylglyceryltrimethylhomoserine (DGTS) and pinolenic acid (18:3$\Delta$5,9,12) increased in the parental strains but decreased in the $crbzip1$ mutants under ER stress. A yeast one-hybrid assay revealed that CrbZIP1 activated the expression of enzymes catalyzing the biosynthesis of DGTS and pinolenic acid. Moreover, two lines harboring independent mutant alleles of $Chlamydomonas\ desaturase\ (CrDES)$ failed to synthesize pinolenic acid and were more sensitive to ER stress than were their parental lines. Together, these results indicate that $CrbZIP1$ is a critical component of the ER stress response mediated by CrIRE1 in Chlamydomonas that acts via lipid remodeling.
Published: 2019

22. Branched-Chain Amino Acid Catabolism Impacts Triacylglycerol Homeostasis in Chlamydomonas reinhardtii

Author: Yariv Brotman, Ismael Torres-Romero, Yonghua Li-Beisson, Stéphan Cuiné, Gilles Peltier, Bertrand Legeret, Emmanuelle Billon, Fantao Kong, Fred Beisson, Adrien Burlacot, Yuanxue Liang, Alisdair R. Fernie, Saleh Alseekh, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Dalian University of Technology, Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Max Planck Institute of Molecular Plant Physiology (MPI-MP), Max-Planck-Gesellschaft, ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), European Project: 664621,H2020,H2020-WIDESPREAD-2014-1,PlantaSYST(2015), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Environnement, Bioénergie, Microalgues et Plantes (EBMP)
Subjects: 0106 biological sciences, 2. Zero hunger, chemistry.chemical_classification, biology, Physiology, Catabolism, Chemistry, Mutant, Chlamydomonas, Branched-chain amino acid, Chlamydomonas reinhardtii, Plant Science, Metabolism, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, biology.organism_classification, 01 natural sciences, Amino acid, chemistry.chemical_compound, Biosynthesis, Biochemistry, Genetics, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, ComputingMilieux_MISCELLANEOUS, 010606 plant biology & botany
Abstract: Nitrogen (N) starvation-induced triacylglycerol (TAG) synthesis, and its complex relationship with starch metabolism in algal cells, has been intensively studied; however, few studies have examined the interaction between amino acid metabolism and TAG biosynthesis. Here, via a forward genetic screen for TAG homeostasis, we isolated a Chlamydomonas (Chlamydomonas reinhardtii) mutant (bkdE1α) that is deficient in the E1α subunit of the branched-chain ketoacid dehydrogenase (BCKDH) complex. Metabolomics analysis revealed a defect in the catabolism of branched-chain amino acids in bkdE1α Furthermore, this mutant accumulated 30% less TAG than the parental strain during N starvation and was compromised in TAG remobilization upon N resupply. Intriguingly, the rate of mitochondrial respiration was 20% to 35% lower in bkdE1α compared with the parental strains. Three additional knockout mutants of the other components of the BCKDH complex exhibited phenotypes similar to that of bkdE1α Transcriptional responses of BCKDH to different N status were consistent with its role in TAG homeostasis. Collectively, these results indicate that branched-chain amino acid catabolism contributes to TAG metabolism by providing carbon precursors and ATP, thus highlighting the complex interplay between distinct subcellular metabolisms for oil storage in green microalgae.
Published: 2019

23. Centrifugation-induced production of triacylglycerols in Chlamydomonas reinhardtii

Author: Tony Lum, Yonghua Li-Beisson, Bertrand Legeret, Ruth Ndathe, Naohiro Kato, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Environmental Engineering, biology, Renewable Energy, Sustainability and the Environment, Chemistry, 020209 energy, [SDV]Life Sciences [q-bio], Chlamydomonas, food and beverages, Chlamydomonas reinhardtii, Bioengineering, 02 engineering and technology, 010501 environmental sciences, biology.organism_classification, 01 natural sciences, Chloroplast, Cell Pellet, Membrane, Biochemistry, 0202 electrical engineering, electronic engineering, information engineering, Centrifugation, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: We found that Chlamydomonas reinhardtii, a model microalga, produces triacylglycerols (TAGs) when the cell pellet is left overnight after centrifugation. The centrifuged cells produce three times more TAGs than those cultured in a nitrogen (N) depletion condition in the first 24 h. The chloroplast membranes of the centrifuged cells are largely disrupted. In addition, the accumulated TAGs contain only trivial amount of C18:1 (11) and C18:3 (5,9,12) fatty acids that are more abundant in TAGs accumulated under N-starved condition. Overall, TAGs that are induced by centrifugation contain more saturated fatty acids than that induced by N starvation. These suggest that the centrifugation triggers the production of TAGs through yet unknown mechanism. An importance of this finding is that not only quantity but also quality of the TAG production can be modified by alternating environmental stimuli rather than genetic means.
Published: 2019

24. Subcellular Energetics and Carbon Storage in Chlamydomonas

Author: Gilles Peltier, Adrien Burlacot, Yonghua Li-Beisson, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Environnement, Bioénergie, Microalgues et Plantes (EBMP)
Subjects: 0106 biological sciences, 0301 basic medicine, organelle, Biomass, Photosynthesis, oil, 01 natural sciences, 7. Clean energy, 03 medical and health sciences, chemistry.chemical_compound, chloroplast, peroxisome, lcsh:QH301-705.5, Fatty acid synthesis, Cellular compartment, photosynthesis, biology, starch, Chlamydomonas, food and beverages, General Medicine, Metabolism, reductant, Peroxisome, biology.organism_classification, Chloroplast, mitochondria, phosphorylating power, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, 030104 developmental biology, chemistry, Biochemistry, lcsh:Biology (General), 13. Climate action, metabolic shuttles, 010606 plant biology & botany
Abstract: International audience; Microalgae have emerged as a promising platform for production of carbon-and energy-rich molecules, notably starch and oil. Establishing an economically viable algal biotechnology sector requires a holistic understanding of algal photosynthesis, physiology, cell cycle and metabolism. Starch/oil productivity is a combined effect of their cellular content and cell division activities. Cell growth, starch and fatty acid synthesis all require carbon building blocks and a source of energy in the form of ATP and NADPH, but with a different requirement in ATP/NADPH ratio. Thus, several cellular mechanisms have been developed by microalgae to balance ATP and NADPH supply which are essentially produced by photosynthesis. Major energy management mechanisms include ATP production by the chloroplast-based cyclic electron flow and NADPH removal by water-water cycles. Furthermore, energetic coupling between chloroplast and other cellular compartments, mitochondria and peroxisome, is increasingly recognized as an important process involved in the chloroplast redox poise. Emerging literature suggests that alterations of energy management pathways affect not only cell fitness and survival, but also influence biomass content and composition. These emerging discoveries are important steps towards diverting algal photosynthetic energy to useful products for biotechnological applications.
Published: 2019

25. Molecular Genetic Tools and Emerging Synthetic Biology Strategies to Increase Cellular Oil Content in Chlamydomonas reinhardtii

Author: Youngsook Lee, Yasuyo Yamaoka, Fantao Kong, Takeshi Ohama, Yonghua Li-Beisson, Pohang University of Science and Technology (POSTECH), Kochi University of Technology (KUT), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Environnement, Bioénergie, Microalgues et Plantes (EBMP)
Subjects: 0106 biological sciences, 0301 basic medicine, Physiology, Oil content, Chlamydomonas reinhardtii, Plant Science, Computational biology, Transgene Expression, 01 natural sciences, Metabolic engineering, 03 medical and health sciences, Synthetic biology, Genome editing, Lipid biosynthesis, Plant Oils, Genome Editing, Organism, Gene Editing, biology, Chlamydomonas, Cell Biology, General Medicine, biology.organism_classification, Algae fuel, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, 030104 developmental biology, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Metabolic Engineering, Synthetic Biology, Genetic Engineering, Triacylglycerol Plant & Cell Physiology, 010606 plant biology & botany
Abstract: International audience; Microalgae constitute a highly diverse group of eukaryotic and photosynthetic microorganisms that have developed extremely efficient systems for harvesting and transforming solar energy into energy-rich molecules such as lipids. Although microalgae are considered to be one of the most promising platforms for the sustainable production of liquid oil, the oil content of these organisms is naturally low, and algal oil production is currently not economically viable. Chlamydomonas reinhardtii (Chlamydomonas) is an established algal model due to its fast growth, high transformation efficiency, and well-understood physiology and to the availability of detailed genome information and versatile molecular tools for this organism. In this review, we summarize recent advances in the development of genetic manipulation tools for Chlamydomonas, from gene delivery methods to state-of-the-art genome-editing technologies and fluorescent dye-based high-throughput mutant screening approaches. Furthermore, we discuss practical strategies and toolkits that enhance transgene expression, such as choice of expression vector and background strain. We then provide examples of how advanced genetic tools have been used to increase oil content in Chlamydomonas. Collectively, the current literature indicates that microalgal oil content can be increased by overexpressing key enzymes that catalyze lipid biosynthesis, blocking lipid degradation, silencing metabolic pathways that compete with lipid biosynthesis and modulating redox state. The tools and knowledge generated through metabolic engineering studies should pave the way for developing a synthetic biological approach to enhance lipid productivity in microalgae.
Published: 2019

26. The Phosphate Fast-Responsive Genes PECP1 and PPsPase1 Affect Phosphocholine and Phosphoethanolamine Content

Author: Fan Lai, Fred Beisson, Yonghua Li-Beisson, Mohamed Hanchi, Bertrand Legeret, Jérôme Mutterer, David Secco, Peter Doerner, Nathalie Pochon, Kashchandra G. Raghothama, Laura Cuyas, Marie Christine Thibaud, Keiko Kuwata, Ali Ferjani, Michel Philibert, Aiqin Cao, Pascale David, Laurent Nussaume, Hélène Javot, Corinne Rivasseau, James Whelan, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Bioénergie et Microalgues (EBM), Nagoya University, Department of Horticulture and Landscape Architecture, Purdue University [West Lafayette], University of Edinburgh, Tokyo Gakugei University, Institut de biologie moléculaire des plantes (IBMP), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Groupe de Recherches Appliquées en Phytotechnologie (GRAP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biosciences et de Biotechnologies de Grenoble (ex-IRTSV) (BIG), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes (UGA), Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), The University of Western Australia (UWA), Centre of Excellence in Plant Energy Biology (ARC), Australian National University (ANU)-School of Biochemistry and Molecular Biology, La Trobe University, La Trobe University [Melbourne], Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Marie Curie International Reintegration grant as part of the 7th European Community Framework Program, CEA IRTELIS fellowship, Agence Nationale de la Recherche REGLISSE project, CNRS 'Instrumentations aux limites', CEA Programme Transversal de Toxicologie, Plant Environmental Physiology and Stress Signaling (PEPSS), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA))
Subjects: 0106 biological sciences, 0301 basic medicine, Physiology, Membrane lipids, [SDV]Life Sciences [q-bio], Phosphatase, Plant Science, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Arabidopsis, Genetics, Arabidopsis thaliana, ComputingMilieux_MISCELLANEOUS, Phosphocholine, 2. Zero hunger, chemistry.chemical_classification, biology, biology.organism_classification, Phosphate, 030104 developmental biology, Enzyme, Biochemistry, chemistry, Starvation response, 010606 plant biology & botany
Abstract: International audience; Phosphate starvation-mediated induction of the HAD-type phosphatases PPsPase1 (AT1G73010) and PECP1 (AT1G17710) has been reported in Arabidopsis (Arabidopsis thaliana). However, little is known about their in vivo function or impact on plant responses to nutrient deficiency. The preferences of PPsPase1 and PECP1 for different substrates have been studied in vitro but require confirmation in planta. Here, we examined the in vivo function of both enzymes using a reverse genetics approach. We demonstrated that PPsPase1 and PECP1 affect plant phosphocholine and phosphoethanolamine content, but not the pyrophosphate-related phenotypes. These observations suggest that the enzymes play a similar role in planta related to the recycling of polar heads from membrane lipids that is triggered during phosphate starvation. Altering the expression of the genes encoding these enzymes had no effect on lipid composition, possibly due to compensation by other lipid recycling pathways triggered during phosphate starvation. Furthermore, our results indicated that PPsPase1 and PECP1 do not influence phosphate homeostasis, since the inactivation of these genes had no effect on phosphate content or on the induction of molecular markers related to phosphate starvation. A combination of transcriptomics and imaging analyses revealed that PPsPase1 and PECP1 display a highly dynamic expression pattern that closely mirrors the phosphate status. This temporal dynamism, combined with the wide range of induction levels, broad expression, and lack of a direct effect on Pi content and regulation, makes PPsPase1 and PECP1 useful molecular markers of the phosphate starvation response.
Published: 2018

27. Interorganelle Communication: Peroxisomal MALATE DEHYDROGENASE 2 Connects Lipid Catabolism to Photosynthesis through Redox Coupling in Chlamydomonas

Author: Saleh Alseekh, Gilles Peltier, Alisdair R. Fernie, Bertrand Legeret, Fantao Kong, Anja Krieger-Liszkay, Fred Beisson, Adrien Burlacot, Yuanxue Liang, Yariv Brotman, Yonghua Li-Beisson, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Max Planck Institute of Molecular Plant Physiology (MPI-MP), Max-Planck-Gesellschaft, Système membranaires, photobiologie, stress et détoxication (SMPSD), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Environnement, Bioénergie, Microalgues et Plantes (EBMP)
Subjects: 0106 biological sciences, 0301 basic medicine, Photosystem II, Chlamydomonas reinhardtii, Plant Science, Biology, Photosynthesis, 01 natural sciences, 03 medical and health sciences, Malate Dehydrogenase, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Research Articles, Chlamydomonas, Hydrogen Peroxide, Cell Biology, Metabolism, Carbon Dioxide, Peroxisome, biology.organism_classification, Electron transport chain, Chloroplast, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, 030104 developmental biology, Biochemistry, Mutation, Oxidation-Reduction, 010606 plant biology & botany
Abstract: International audience; Plants and algae must tightly coordinate photosynthetic electron transport and metabolic activities given that they often face fluctuating light and nutrient conditions. The exchange of metabolites and signaling molecules between organelles is thought to be central to this regulation but evidence for this is still fragmentary. Here we show that knocking out the peroxisome-located MALATE DEHYDROGENASE 2 (MDH2) of Chlamydomonas reinhardtii results in dramatic alterations not only in peroxisomal fatty acid breakdown but also in chloroplast starch metabolism and photosynthesis. mdh2 mutants accumulated 50% more storage lipid and twofold more starch than wild type during nitrogen deprivation. In parallel, mdh2 showed increased PSII yield and photosynthetic CO 2 fixation. Metabolite analyses revealed a >60% reduction in malate, together with increased levels of NADPH and H 2 O 2 in mdh2. Similar phenotypes were found upon high light exposure. Furthermore, based on the lack of starch accumulation in a knockout mutant of the H 2 O 2-producing peroxisomal ACYL-COA OXIDASE 2 and on the effects of H 2 O 2 supplementation, we propose that peroxisome-derived H 2 O 2 acts as a regulator of chloroplast metabolism. We conclude that peroxisomal MDH2 helps photoautotrophs cope with nitrogen scarcity and high light by transmitting the redox state of the peroxisome to the chloroplast by means of malate shuttle-and H 2 O 2-based redox signaling.
Published: 2018

28. The Chlamydomonas mex1 mutant shows impaired starch mobilization without maltose accumulation

Author: Christophe D'Hulst, Jean-Marie Lacroix, Gilles Peltier, Thierry Duchêne, Fabrice Wattebled, Yonghua Li-Beisson, Corentin Spriet, David Dauvillée, Nicolas Szydlowski, Miriam Schulz-Raffelt, Philippe Deschamps, Hande Tunçay, Justin Findinier, Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Ecologie Systématique et Evolution (ESE), Université Paris-Sud - Paris 11 (UP11)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Miniaturisation pour la Synthèse, l’Analyse et la Protéomique - UAR 3290 (MSAP), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Miniaturisation pour la Synthèse, l’Analyse et la Protéomique - USR 3290 (MSAP), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, Monosaccharide Transport Proteins, Physiology, Recombinant Fusion Proteins, [SDV]Life Sciences [q-bio], Mutant, Arabidopsis, Chlamydomonas reinhardtii, Gene Expression, Plant Science, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Genes, Reporter, Escherichia coli, Plastids, Transgenes, Plastid envelope, Maltose, Phylogeny, ComputingMilieux_MISCELLANEOUS, biology, Chemistry, Chlamydomonas, Algal Proteins, food and beverages, Biological Transport, Starch, biology.organism_classification, Complementation, 030104 developmental biology, Biochemistry, Seedlings, Mutation, Heterologous expression, 010606 plant biology & botany
Abstract: The MEX1 locus of Chlamydomonas reinhardtii was identified in a genetic screen as a factor that affects starch metabolism. Mutation of MEX1 causes a slow-down in the mobilization of storage polysaccharide. Cosegregation and functional complementation analyses were used to assess the involvement of the Mex1 protein in starch degradation. Heterologous expression experiments performed in Escherichia coli and Arabidopsis thaliana allowed us to test the capacity of the algal protein in maltose export. In contrast to the A. thaliana mex1 mutant, the mutation in C. reinhardtii does not lead to maltose accumulation and growth impairment. Although localized in the plastid envelope, the algal protein does not transport maltose efficiently across the envelope, but partly complements the higher plant mutant. Both Mex orthologs restore the growth of the E. coli ptsG mutant strain on glucose-containing medium, revealing the capacity of these proteins to transport this hexose. These findings suggest that Mex1 is essential for starch mobilization in both Chlamydomonas and Arabidopsis, and that this protein family may support several functions and not only be restricted to maltose export across the plastidial envelope.
Published: 2017

29. An algal photoenzyme converts fatty acids to hydrocarbons

Author: Bertrand Légeret, Pavel Müller, Yonghua Li-Beisson, Yohann Couté, David Pignol, Fred Beisson, Gilles Peltier, Damien Sorigué, Emmanuelle Billon, Stéphanie Blangy, Didier Nurizzo, Pascal Arnoux, Pierre Richaud, Solène L. Y. Moulin, Klaus Brettel, Stéphan Cuiné, Sabine Brugière, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Synthèse et étude de systèmes à intêret biologique (SEESIB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), Troubles cognitifs dégénératifs et vasculaires (DN2M), Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-INSERM, Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Etude de la dynamique des protéomes (EDyP), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA), European Synchrotron Radiation Facility (ESRF), Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Microbiologie Environnementale et Moléculaire (MEM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Etude de la dynamique des protéomes (EDyP ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-10-INBS-0008,ProFI,Infrastructure Française de Protéomique(2010), Biologie végétale et microbiologie environnementale - UMR7265 ( BVME ), Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Aix Marseille Université ( AMU ), Laboratoire de Biologie à Grande Échelle ( BGE - UMR S1038 ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Grenoble Alpes [Saint Martin d'Hères]-Institut National de la Santé et de la Recherche Médicale ( INSERM ), European Synchrotron Radiation Facility ( ESRF ), Biologie et Biotechnologie des Cyanobactéries ( B2CYA ), Département Microbiologie ( Dpt Microbio ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), and Environnement, Bioénergie, Microalgues et Plantes (EBMP)
Subjects: 0301 basic medicine, Photosynthetic reaction centre, Light, Carboxy-Lyases, Decarboxylation, [SDV]Life Sciences [q-bio], Chlorella, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Alkenes, 010402 general chemistry, 01 natural sciences, Cofactor, 03 medical and health sciences, chemistry.chemical_compound, Oxidoreductase, Alkanes, Phylogeny, ComputingMilieux_MISCELLANEOUS, Plant Proteins, chemistry.chemical_classification, Flavin adenine dinucleotide, Multidisciplinary, biology, [ SDV.BC ] Life Sciences [q-bio]/Cellular Biology, Fatty Acids, Fatty acid, Lipid metabolism, Lipid Metabolism, Photochemical Processes, 0104 chemical sciences, 030104 developmental biology, Enzyme, chemistry, Biochemistry, Biocatalysis, Flavin-Adenine Dinucleotide, biology.protein, Oxidoreductases
Abstract: Algal enzyme driven by blue light Microalgae make hydrocarbons. In searching for the enzyme responsible, Sorigué et al. found a glucose-methanolcholine oxidoreductase (see the Perspective by Scrutton). Expression of the enzyme in Escherichia coli showed that hydrocarbon production requires visible light. In fact, the enzyme requires a constant input of blue photons to carry out its catalytic reaction. A long hydrophobic tunnel in the enzyme stabilizes the fatty acid substrates in proximity to the flavin adenine dinucleotide cofactor. Science , this issue p. 903 ; see also p. 872
Published: 2017

30. Chlamydomonas carries out fatty acid β-oxidation in ancestral peroxisomes using a bona fide acyl-CoA oxidase

Author: Bertrand Legeret, Audrey Beyly-Adriano, Johnathan A. Napier, Yuanxue Liang, Gilles Peltier, Stéphanie Blangy, Fantao Kong, Fred Beisson, Yonghua Li-Beisson, Richard P. Haslam, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biological Chemistry and Crop Protection, Rothamsted Research, Biotechnology and Biological Sciences Research Council (BBSRC)-Biotechnology and Biological Sciences Research Council (BBSRC), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, Nitrogen, Mutant, Chlamydomonas reinhardtii, lipid droplet, hydrogen peroxide, Plant Science, 01 natural sciences, 03 medical and health sciences, Peroxisomes, Genetics, microbodies, Acyl-CoA oxidase, Microbody, nitrogen starvation, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], chemistry.chemical_classification, Oxidase test, biology, Chlamydomonas, catalase, acyl-CoA oxidase, Fatty acid, lipid catabolism, Cell Biology, Peroxisome, Lipid Metabolism, biology.organism_classification, lipid homeostasis, 030104 developmental biology, Biochemistry, chemistry, oil content, Oxidation-Reduction, 010606 plant biology & botany
Abstract: International audience; Peroxisomes are thought to have played a key role in the evolution of metabolic networks of photosynthetic organisms by connecting oxidative and biosynthetic routes operating in different compartments. While the various oxidative pathways operating in the peroxisomes of higher plants are fairly well characterized, the reactions present in the primitive peroxisomes (microbodies) of algae are poorly understood. Screening of a Chlamydomonas insertional mutant library identified a strain strongly impaired in oil remobilization and defective in Cre05.g232002(CrACX2), a gene encoding a member of the acyl-CoA oxidase/dehydrogenase superfamily. The purified recombinant CrACX2 expressed in Escherichia coli catalyzed the oxidation of fatty acyl-CoAs into trans-2-enoyl-CoA and produced H 2 O 2. This result demonstrated that CrACX2 is a genuine acyl-CoA oxidase, which is responsible for the first step of the peroxisomal fatty acid (FA) β-oxidation spiral. A fluorescent protein-tagging study pointed to a peroxisomal location of CrACX2. The importance of peroxisomal FA β-oxidation in algal physiology was shown by the impact of the mutation on FA turnover during day/night cycles. Moreover, under nitrogen depletion the mutant accumulated 20% more oil than the wild type, illustrating the potential of β-oxidation mutants for algal biotechnology. This study provides experimental evidence that a plant-type FA β-oxidation involving H 2 O 2-producing acyl-CoA oxidation activity has already evolved in the microbodies of the unicellular green alga Chlamydomonas reinhardtii.
Published: 2017

31. Plant membrane-protein mediated intracellular traffic of fatty acids and acyl lipids

Author: Youngsook Lee, Jens Neunzig, Yonghua Li-Beisson, Katrin Philippar, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Universität des Saarlandes [Saarbrücken], Pohang University of Science and Technology (POSTECH), Ludwig Maximilian University [Munich] (LMU), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0301 basic medicine, Organelles, Endoplasmic reticulum, fungi, food and beverages, Plant Science, Mitochondrion, Biology, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Transport protein, Cell biology, 03 medical and health sciences, Membrane Lipids, 030104 developmental biology, Biochemistry, Membrane protein, Lipid droplet, Organelle, lipids (amino acids, peptides, and proteins), Plastid, Plant lipid transfer proteins, Plant Physiological Phenomena, Plant Proteins
Abstract: International audience; In plants, de novo synthesis of fatty acids (FAs) occurs in plastids, whereas assembly and modification of acyl lipids is accomplished in the endoplasmic reticulum (ER) and plastids as well as in mitochondria. Subsequently, lipophilic compounds are distributed within the cell and delivered to their destination site. Thus, constant acyl-exchanges between subcellular compartments exist. These can occur via several modes of transport and plant membrane-intrinsic proteins for FA/lipid transfer have been shown to play an essential role in delivery and distribution. Lately, substantial progress has been made in identification and characterization of transport proteins for lipid compounds in plant organelle membranes. In this review, we focus on our current understanding of protein mediated lipid traffic between organelles of land plants.
Published: 2017

32. Hyper-accumulation of starch and oil in a Chlamydomonas mutant affected in a plant-specific DYRK kinase

Author: Pascaline Auroy, Vincent Chochois, Emmanuelle Billon, Yonghua Li-Beisson, David Dauvillée, Miriam Schulz-Raffelt, Stéphan Cuiné, Gilles Peltier, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Support was also provided by the HélioBiotec platform (funded by the European Regional Development Fund, the Région Provence Alpes Côte d’Azur, the French Ministry of Research, and the 'Commissariat à l’Energie Atomique et aux Energies Alternatives')., ANR-08-BIOE-0002,ALGOMICS,ETUDES GLOBALES DE LA CONVERSION ET DU STOCKAGE DE L'ENERGIE CHEZ LES MICROALGUES(2008), ANR-10-BIOE-0004,Algo-H2,Optimisations génétiques, métaboliques, et procédé de la photobioproduction d'hydrogène par la microalgue verte Chlamydomonas reinhardtii(2010), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), CNRS, Université de Lille, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) [BIAM], Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 [UGSF], Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), ANR: ALGOH2,Optimisations génétiques, métaboliques, et procédé de photobioproduction d’hydrogène par la microalgue verte Chlamydomonas reinhardtii, and ANR-11-IDEX-0001-02/11-IDEX-0001,AMIDEX,AMIDEX(2011)
Subjects: 0301 basic medicine, Kinase, Nutrient deprivation, Oil, Starch, Microalgae, Photosynthesis, Chlamydomonas, DYRK, [SDV]Life Sciences [q-bio], Mutant, Chlamydomonas reinhardtii, Management, Monitoring, Policy and Law, 7. Clean energy, Applied Microbiology and Biotechnology, 03 medical and health sciences, chemistry.chemical_compound, Nutrient, Botany, 2. Zero hunger, biology, Renewable Energy, Sustainability and the Environment, Research, biology.organism_classification, Cell biology, 030104 developmental biology, General Energy, chemistry, Biofuel, Biotechnology
Abstract: Background Because of their high biomass productivity and their ability to accumulate high levels of energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production of biofuel. Accumulation of reserve compounds takes place when microalgae face adverse situations such as nutrient shortage, conditions which also provoke a stop in cell division, and down-regulation of photosynthesis. Despite growing interest in microalgal biofuels, little is known about molecular mechanisms controlling carbon reserve formation. In order to discover new regulatory mechanisms, and identify genes of interest to boost the potential of microalgae for biofuel production, we developed a forward genetic approach in the model microalga Chlamydomonas reinhardtii. Results By screening an insertional mutant library on the ability of mutants to accumulate and re-mobilize reserve compounds, we isolated a Chlamydomonas mutant (starch degradation 1, std1) deficient for a dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK). The std1 mutant accumulates higher levels of starch and oil than wild-type and maintains a higher photosynthetic activity under nitrogen starvation. Phylogenetic analysis revealed that this kinase (named DYRKP) belongs to a plant-specific subgroup of the evolutionarily conserved DYRK kinase family. Furthermore, hyper-accumulation of storage compounds occurs in std1 mostly under low light in photoautotrophic condition, suggesting that the kinase normally acts under conditions of low energy status to limit reserve accumulation. Conclusions The DYRKP kinase is proposed to act as a negative regulator of the sink capacity of photosynthetic cells that integrates nutrient and energy signals. Inactivation of the kinase strongly boosts accumulation of reserve compounds under photoautotrophic nitrogen deprivation and allows maintaining high photosynthetic activity. The DYRKP kinase therefore represents an attractive target for improving the energy density of microalgae or crop plants. Electronic supplementary material The online version of this article (doi:10.1186/s13068-016-0469-2) contains supplementary material, which is available to authorized users.
Published: 2016

33. Whole genome re-sequencing identifies a quantitative trait locus repressing carbon reserve accumulation during optimal growth in $Chlamydomonas\ reinhardtii$

Author: Emmanuelle Billon, Yonghua Li-Beisson, Fantao Kong, Gilles Peltier, Fred Beisson, Bertrand Legeret, Audrey Beyly-Adriano, Hugh D. Goold, Stéphan Cuiné, Hoa Mai Nguyen, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), The University of Sydney, OSEO : 'Exploitation Industrielle des Micro-Algues', ANR-12-BIME-0001,DIESALG,Production de biodiesel par microalgues(2012), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0106 biological sciences, 0301 basic medicine, Light, [SDV]Life Sciences [q-bio], Mutant, Quantitative Trait Loci, Chlamydomonas reinhardtii, Quantitative trait locus, 01 natural sciences, 7. Clean energy, Genome, Genetic analysis, Article, 03 medical and health sciences, Gene, ComputingMilieux_MISCELLANEOUS, 2. Zero hunger, Genetics, Multidisciplinary, biology, Starch, Sequence Analysis, DNA, biology.organism_classification, Carbon, Light intensity, 030104 developmental biology, Biochemistry, Chromosomal region, Mutation, Oils, Metabolic Networks and Pathways, 010606 plant biology & botany
Abstract: Microalgae have emerged as a promising source for biofuel production. Massive oil and starch accumulation in microalgae is possible, but occurs mostly when biomass growth is impaired. The molecular networks underlying the negative correlation between growth and reserve formation are not known. Thus isolation of strains capable of accumulating carbon reserves during optimal growth would be highly desirable. To this end, we screened an insertional mutant library of Chlamydomonas reinhardtii for alterations in oil content. A mutant accumulating five times more oil and twice more starch than wild-type during optimal growth was isolated and named constitutive oil accumulator 1 (coa1). Growth in photobioreactors under highly controlled conditions revealed that the increase in oil and starch content in coa1 was dependent on light intensity. Genetic analysis and DNA hybridization pointed to a single insertional event responsible for the phenotype. Whole genome re-sequencing identified in coa1 a >200 kb deletion on chromosome 14 containing 41 genes. This study demonstrates that, 1), the generation of algal strains accumulating higher reserve amount without compromising biomass accumulation is feasible; 2), light is an important parameter in phenotypic analysis; and 3), a chromosomal region (Quantitative Trait Locus) acts as suppressor of carbon reserve accumulation during optimal growth.
Published: 2016

34. Identification of a Chlamydomonas plastidial 2-lysophosphatidic acid acyltransferase and its use to engineer microalgae with increased oil content

Author: Yeongho Kim, Miriam Schulz-Raffelt, Shogo Kamisuki, Yonghua Li-Beisson, Sunghoon Jang, Youngsook Lee, Won-Yong Song, Donghwi Ko, Bertrand Legeret, Yasuyo Yamaoka, Dorine Achard, Ikuo Nishida, Pohang University of Science and Technology (POSTECH), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Saitama University, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), ANR-13-JSV5-0005,MUsCA,Ingénierie métabolique d'une microalgue verte en vue de la production d'alcanes à chaine moyenne(2013), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0106 biological sciences, 0301 basic medicine, lysophosphatidic acid acyltransferase, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, Plastid membrane, Plant Science, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, triacylglycerols, Plant Oils, Plastids, Plastid, Research Articles, ComputingMilieux_MISCELLANEOUS, biology, microalgae, Chlamydomonas, Phosphatidic acid, biology.organism_classification, Enzyme assay, 030104 developmental biology, Biochemistry, chemistry, acyl specificity, Acyltransferases, plastid transformation, oil content, Acyltransferase, biology.protein, Agronomy and Crop Science, 010606 plant biology & botany, Biotechnology, Research Article
Abstract: Summary Despite a strong interest in microalgal oil production, our understanding of the biosynthetic pathways that produce algal lipids and the genes involved in the biosynthetic processes remains incomplete. Here, we report that Chlamydomonas reinhardtii Cre09.g398289 encodes a plastid‐targeted 2‐lysophosphatidic acid acyltransferase (CrLPAAT1) that acylates the sn‐2 position of a 2‐lysophosphatidic acid to form phosphatidic acid, the first common precursor of membrane and storage lipids. In vitro enzyme assays showed that CrLPAAT1 prefers 16:0‐CoA to 18:1‐CoA as an acyl donor. Fluorescent protein‐tagged CrLPAAT1 was localized to the plastid membrane in C. reinhardtii cells. Furthermore, expression of CrLPAAT1 in plastids led to a > 20% increase in oil content under nitrogen‐deficient conditions. Taken together, these results demonstrate that CrLPAAT1 is an authentic plastid‐targeted LPAAT in C. reinhardtii, and that it may be used as a molecular tool to genetically increase oil content in microalgae.
Published: 2016

35. Lipids: From Chemical Structures, Biosynthesis, and Analyses to Industrial Applications

Author: Yuki Nakamura, John L. Harwood, Yonghua Li-Beisson, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Cardiff University, Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, 0301 basic medicine, 2. Zero hunger, business.industry, media_common.quotation_subject, [SDV]Life Sciences [q-bio], Biomass, Lipid metabolism, Biology, Cell biomass, 01 natural sciences, Biotechnology, 03 medical and health sciences, 030104 developmental biology, Energy density, Biochemical engineering, business, Function (engineering), ComputingMilieux_MISCELLANEOUS, 010606 plant biology & botany, media_common
Abstract: Lipids are one of the major subcellular components, and play numerous essential functions. As well as their physiological roles, oils stored in biomass are useful commodities for a variety of biotechnological applications including food, chemical feedstocks, and fuel. Due to their agronomic as well as economic and societal importance, lipids have historically been subjected to intensive studies. Major current efforts are to increase the energy density of cell biomass, and/or create designer oils suitable for specific applications. This chapter covers some basic aspects of what one needs to know about lipids: definition, structure, function, metabolism and focus is also given on the development of modern lipid analytical tools and major current engineering approaches for biotechnological applications. This introductory chapter is intended to serve as a primer for all subsequent chapters in this book outlining current development in specific areas of lipids and their metabolism.
Published: 2016

36. Fatty Acid and Lipid Transport in Plant Cells

Author: Yonghua Li-Beisson, Nannan Li, Changcheng Xu, Katrin Philippar, Southwest University [Chongqing], Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Plant Biochemistry and Physiology, Ludwig-Maximilians-Universität München (LMU), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: 0106 biological sciences, 0301 basic medicine, [SDV]Life Sciences [q-bio], Plant Development, Chlamydomonas reinhardtii, Plant Science, 01 natural sciences, 03 medical and health sciences, Plant Cells, Lipid droplet, Plastid, Lipid Transport, ComputingMilieux_MISCELLANEOUS, Organelles, chemistry.chemical_classification, biology, Endoplasmic reticulum, Cell Membrane, Fatty Acids, food and beverages, Fatty acid, Biological Transport, Lipid metabolism, biology.organism_classification, Membrane contact site, Cell biology, 030104 developmental biology, Biochemistry, chemistry, 010606 plant biology & botany
Abstract: Fatty acids (FAs) and lipids are essential - not only as membrane constituents but also for growth and development. In plants and algae, FAs are synthesized in plastids and to a large extent transported to the endoplasmic reticulum for modification and lipid assembly. Subsequently, lipophilic compounds are distributed within the cell, and thus are transported across most membrane systems. Membrane-intrinsic transporters and proteins for cellular FA/lipid transfer therefore represent key components for delivery and dissemination. In addition to highlighting their role in lipid homeostasis and plant performance, different transport mechanisms for land plants and green algae - in the model systems Arabidopsis thaliana, Chlamydomonas reinhardtii - are compared, thereby providing a current perspective on protein-mediated FA and lipid trafficking in photosynthetic cells.
Published: 2016

37. The small molecule fenpropimorph rapidly converts chloroplast membrane lipids to triacylglycerols in Chlamydomonas reinhardtii

Author: Yonghua Li-Beisson, Sunghoon Jang, Ikuo Nishida, Won-Yong Song, Yasuyo Yamaoka, Sangwoo Kim, Hanul Kim, Daewoong Hong, Youngsook Lee, Division of Molecular and Life Sciences, Pohang University of Science and Technology (POSTECH), Division of Life Science, Saitama University, Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Bioénergie et Microalgues (EBM)
Subjects: Microbiology (medical), lcsh:QR1-502, Chlamydomonas reinhardtii, Biology, 7. Clean energy, Microbiology, Chloroplast membrane, lcsh:Microbiology, Chlamydomonas reinhardtii fenpropimorph, chemistry.chemical_compound, Botany, membrane lipid recycling, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Original Research Article, 2. Zero hunger, Fenpropimorph, Chlamydomonas, food and beverages, Metabolism, biology.organism_classification, fenpropimorph, Chloroplast, Algae fuel, Biochemistry, chemistry, 13. Climate action, Biodiesel production, biofuel, triacylglycerol
Abstract: International audience; Concern about global warming has prompted an intense interest in developing economical methods of producing biofuels. Microalgae provide a promising platform for biofuel production, because they accumulate high levels of lipids, and do not compete with food or feed sources. However, current methods of producing algal oil involve subjecting the microalgae to stress conditions, such as nitrogen deprivation, and are prohibitively expensive. Here, we report that the fungicide fenpropimorph rapidly causes high levels of neutral lipids to accumulate in Chlamydomonas reinhardtii cells. When treated with fenpropimorph (10 μg mL −1) for 1 h, Chlamydomonas cells accumulated at least fourfold the amount of triacylglycerols (TAGs) present in the untreated control cells. Furthermore, the quantity of TAGs present after 1 h of fenpropimorph treatment was over twofold higher than that formed after 9 days of nitrogen starvation in medium with no acetate supplement. Biochemical analysis of lipids revealed that the accumulated TAGs were derived mainly from chloroplast polar membrane lipids. Such a conversion of chloroplast polar lipids toTAGs is desirable for biodiesel production, because polar lipids are usually removed during the biodiesel production process. Thus, our data exemplified that a cost and time effective method of producing TAGs is possible using fenpropimorph or similar drugs.
Published: 2015

38. Development and validation of a screening procedure of microalgae for biodiesel production: Application to the genus of marine microalgae Nannochloropsis

Author: Boris Mirabella, Hosni Takache, Ahmed Taleb, Bertrand Legeret, B. Le-Gouic, S. Bouvet, H. Marec, Jack Legrand, Yonghua Li-Beisson, Gilles Peltier, Jeremy Pruvost, Samir Taha, Bioprocédés Appliqués aux Microalgues (GEPEA-BAM), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes (LEMIRE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Bioénergie et Microalgues (EBM), Université Libanaise, Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Laboratoire d'Electronique Quantique, Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB)-Faculté de Physique, Mines Nantes (Mines Nantes)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO), Institut de Chimie de Clermont-Ferrand (ICCF), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)-Centre National de la Recherche Scientifique (CNRS), Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Lebanese University, AZM Center for Biotechnology Research and Its Applications, Lebanese University, Department of Food Science and Technology, Faculty of Agricultural and Veterinary Medecine, Université de Bretagne Sud (UBS)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO), and Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)
Subjects: Aquatic Organisms, Environmental Engineering, Time Factors, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [SDV]Life Sciences [q-bio], Photobioreactor, Bioengineering, Mass Spectrometry, Photobioreactors, Bioenergy, Botany, Bioreactor, Microalgae, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Food science, Biomass, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, Triglycerides, Biodiesel, biology, Renewable Energy, Sustainability and the Environment, Fatty Acids, Reproducibility of Results, General Medicine, biology.organism_classification, Lipids, Kinetics, Productivity (ecology), Biofuel, Biodiesel production, Biofuels, Nannochloropsis, Stramenopiles, Biotechnology, Chromatography, Liquid
Abstract: International audience; Nannochloropsis has emerged as a promising alga for biodiesel production. However, the genus consists of 6 species and hundreds of strains making strain selection a challenge. Furthermore, oil productivity is instrumental to economic viability of any algal strain for industrial production, which is dependent on growth rate and oil content. In most cases, these two parameters have been studied independently. Thus, the goal of this study is to provide a combined method for evaluating strain performance in specially designed photobioreactors together with an in-depth lipidomic analyses. The nine strains of Nannochloropsis tested showed considerable variations in productivity and lipidomics highlighting the importance of strain selection. Finally, Nannochloropsis gaditana CCMP527 and Nannochloropsis salina CCMP537 emerged as the two most promising strains, with an oil content of 37 and 27 dry wt% after 11-day nitrogen starvation, respectively, resulting in TAG productivity of 13 × 10−3 and 18 × 10−3 kg m−3 d−1, respectively.
Published: 2015

39. Rapid induction of lipid droplets in Chlamydomonas reinhardtii and Chlorella vulgaris by Brefeldin A

Author: Ikuo Nishida, Toshiki Ishikawa, Masumi Otsuru, Maki Kawai-Yamada, Sangwoo Kim, Donghwi Ko, Yasuyo Yamaoka, Yonghua Li-Beisson, Youngsook Lee, Hanul Kim, Hee-Mock Oh, Pohang University of Science and Technology (POSTECH), Saitama University, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-12-BIME-0001,DIESALG,Production de biodiesel par microalgues(2012), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Algae, Membrane lipids, Science, [SDV]Life Sciences [q-bio], Chlorella vulgaris, Chlamydomonas reinhardtii, Gene Expression, Biology, 7. Clean energy, 01 natural sciences, Fluorescence, 03 medical and health sciences, chemistry.chemical_compound, Membrane Lipids, Lipid droplet, Oxazines, Chemical synthesis, Fatty acids, Triglycerides, 030304 developmental biology, 0303 health sciences, Multidisciplinary, Brefeldin A, Chlamydomonas, Algal Proteins, Nile red, biology.organism_classification, Endoplasmic Reticulum Stress, Lipids, Cell staining, Culture Media, chemistry, Biochemistry, Biofuels, Unfolded protein response, Medicine, Endoplasmic reticulum, 010606 plant biology & botany, Research Article
Abstract: International audience; Algal lipids are the focus of intensive research because they are potential sources of biodiesel. However, most algae produce neutral lipids only under stress conditions. Here, we report that treatment with Brefeldin A (BFA), a chemical inducer of ER stress, rapidly triggers lipid droplet (LD) formation in two different microalgal species, Chlamydomonas reinhardtii and Chlorella vulgaris. LD staining using Nile red revealed that BFA-treated algal cells exhibited many more fluorescent bodies than control cells. Lipid analyses based on thin layer chromatography and gas chromatography revealed that the additional lipids formed upon BFA treatment were mainly Triacylglycerols (TAGs). The increase in TAG accumulation was accompanied by a decrease in the betaine lipid diacylglyceryl N,N,N-trimethylhomoserine (DGTS), a major component of the extraplastidic membrane lipids in Chlamydomonas, suggesting that at least some of the TAGs were assembled from the degradation products of membrane lipids. Interestingly, BFA induced TAG accumulation in the Chlamydomonas cells regardless of the presence or absence of an acetate or nitrogen source in the medium. This effect of BFA in Chlamydomonas cells seems to be due to BFA-induced ER stress, as supported by the induction of three homologs of ER stress marker genes by the drug. Together, these results suggest that ER stress rapidly triggers TAG accumulation in two green microalgae, C. reinhardtii and C. vulgaris. A further investigation of the link between ER stress and TAG synthesis may yield an efficient means of producing biofuel from algae.
Published: 2013

40. Development of a forward genetic screen to isolate oil mutants in the green microalga Chlamydomonas reinhardtii

Author: Audrey Beyly-Adriano, Gilles Peltier, Hoa Mai Nguyen, Fred Beisson, Stéphan Cuiné, Caroline Cagnon, Boris Mirabella, Yonghua Li-Beisson, Séverine Bouvet, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ANR-12-BIME-0001,DIESALG,Production de biodiesel par microalgues(2012), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, [SDV]Life Sciences [q-bio], Mutant, Mutagenesis (molecular biology technique), Chlamydomonas reinhardtii, Management, Monitoring, Policy and Law, Biology, Genetic screen, 01 natural sciences, Applied Microbiology and Biotechnology, 03 medical and health sciences, Bioenergy, Botany, Chlamydomonas mutants, Food science, Flow cytometry, 030304 developmental biology, 2. Zero hunger, 0303 health sciences, Biodiesel, Microalgal oil, Renewable Energy, Sustainability and the Environment, Lipid remobilization, Chlamydomonas, Methodology, Nile red, biology.organism_classification, General Energy, Biofuel, 010606 plant biology & botany, Biotechnology
Abstract: International audience; Oils produced by microalgae are precursors to biodiesel. To achieve a profitable production of biodiesel from microalgae, identification of factors governing oil synthesis and turnover is desirable. The green microalga Chlamydomonas reinhardtii is amenable to genetic analyses and has recently emerged as a model to study oil metabolism. However, a detailed method to isolate various types of oil mutants that is adapted to Chlamydomonas has not been reported.ResultsWe describe here a forward genetic approach to isolate mutants altered in oil synthesis and turnover from C. reinhardtii. It consists of a three-step screening procedure: a primary screen by flow cytometry of Nile red stained transformants grown in 96-deep-well plates under three sequential conditions (presence of nitrogen, then absence of nitrogen, followed by oil remobilization); a confirmation step using Nile red stained biological triplicates; and a validation step consisting of the quantification by thin layer chromatography of oil content of selected strains. Thirty-one mutants were isolated by screening 1,800 transformants generated by random insertional mutagenesis (1.7%). Five showed increased oil accumulation under the nitrogen-replete condition and 13 had altered oil content under nitrogen-depletion. All mutants were affected in oil remobilization.ConclusionThis study demonstrates that various types of oil mutants can be isolated in Chlamydomonas based on the method set-up here, including mutants accumulating oil under optimal biomass growth. The strategy conceived and the protocol set-up should be applicable to other microalgal species such as Nannochloropsis and Chlorella, thus serving as a useful tool in Chlamydomonas oil research and algal biotechnology.
Published: 2013

41. The Green Microalga Chlamydomonas reinhardtii Has a Single -3 Fatty Acid Desaturase That Localizes to the Chloroplast and Impacts Both Plastidic and Extraplastidic Membrane Lipids

Author: Stéphan Cuiné, Bertrand Legeret, Hoa Mai Nguyen, Yonghua Li-Beisson, Gilles Peltier, Pascaline Auroy, Emmanuelle Billon, Audrey Beyly-Adriano, Fred Beisson, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, Fatty Acid Desaturases, Chloroplasts, Light, Transcription, Genetic, Physiology, [SDV]Life Sciences [q-bio], Mutant, Chlamydomonas reinhardtii, Fluorescent Antibody Technique, Plant Science, 01 natural sciences, Microalgae, Promoter Regions, Genetic, In Situ Hybridization, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, 0303 health sciences, biology, Temperature, Adaptation, Physiological, Chloroplast, Biochemistry, Polyunsaturated fatty acid, Subcellular Fractions, DNA, Plant, Molecular Sequence Data, Models, Biological, 03 medical and health sciences, Membrane Lipids, Transformation, Genetic, Biochemistry and Metabolism, Sequence Homology, Nucleic Acid, Fatty Acids, Omega-3, Genetics, Amino Acid Sequence, Plastid, 030304 developmental biology, Cell Nucleus, Genetic Complementation Test, Wild type, Fatty acid, biology.organism_classification, Mutagenesis, Insertional, Fatty acid desaturase, chemistry, Genetic Loci, Mutation, biology.protein, DNA Transposable Elements, 010606 plant biology & botany
Abstract: International audience; The v-3 polyunsaturated fatty acids account for more than 50% of total fatty acids in the green microalga Chlamydomonas reinhardtii, where they are present in both plastidic and extraplastidic membranes. In an effort to elucidate the lipid desaturation pathways in this model alga, a mutant with more than 65% reduction in total v-3 fatty acids was isolated by screening an insertional mutant library using gas chromatography-based analysis of total fatty acids of cell pellets. Molecular genetics analyses revealed the insertion of a TOC1 transposon 113 bp upstream of the ATG start codon of a putative v-3 desaturase (CrFAD7; locus Cre01.g038600). Nuclear genetic complementation of crfad7 using genomic DNA containing CrFAD7 restored the wild-type fatty acid profile. Under standard growth conditions, the mutant is indistinguishable from the wild type except for the fatty acid difference, but when exposed to short-term heat stress, its photosynthesis activity is more thermotolerant than the wild type. A comparative lipidomic analysis of the crfad7 mutant and the wild type revealed reductions in all v-3 fatty acid-containing plastidic and extraplastidic glycerolipid molecular species. CrFAD7 was localized to the plastid by immunofluorescence in situ hybridization. Transformation of the crfad7 plastidial genome with a codon-optimized CrFAD7 restored the v-3 fatty acid content of both plastidic and extraplastidic lipids. These results show that CrFAD7 is the only v-3 fatty acid desaturase expressed in C. reinhardtii, and we discuss possible mechanisms of how a plastid-located desaturase may impact the v-3 fatty acid content of extraplastidic lipids.
Published: 2013

42. Comparison of various microalgae liquid biofuel production pathways based on energetic, economic and environmental criteria

Author: C. Sahut, Florian Delrue, Gilles Peltier, A. Roubaud, Yonghua Li-Beisson, A.-K. Froment, P.-A. Setier, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Environmental Engineering, 020209 energy, [SDV]Life Sciences [q-bio], Biomass, Bioengineering, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, 7. Clean energy, Bioenergy, Alkanes, Microalgae, 0202 electrical engineering, electronic engineering, information engineering, Production (economics), Anaerobiosis, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Biodiesel, Waste management, Renewable Energy, Sustainability and the Environment, Chemistry, business.industry, General Medicine, Models, Theoretical, Pulp and paper industry, Renewable energy, Hydrothermal liquefaction, Algae fuel, 13. Climate action, Biofuel, Biofuels, Thermodynamics, business, Oils, Biotechnology
Abstract: In view of the increasing demand for bioenergy, in this study, the techno-economic viabilities for three emerging pathways to microalgal biofuel production have been evaluated. The three processes evaluated are the hydrothermal liquefaction (HTL), oil secretion and alkane secretion. These three routes differ in their lipid extraction procedure and the end-products produced. This analysis showed that these three processes showed various advantages: possibility to convert the defatted microalgae into bio-crude via HTL thus increasing the total biodiesel yield; better energetic and environmental performance for oil secretion and an even increased net energy ratio (NER) for alkane secretion. However, great technological breakthroughs are needed before planning any scale-up strategy such as continuous wet biomass processing and heat exchange optimization for the HTL pathway and effective and sustainable excretion for both secretion pathways.
Published: 2013

43. Solving the puzzles of cutin and suberin polymer biosynthesis

Author: Yonghua Li-Beisson, Fred Beisson, Mike Pollard, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Plant Biology - Michigan State University, Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Polymers, [SDV]Life Sciences [q-bio], Plant Science, Cutin, Biology, Models, Biological, 01 natural sciences, Plant Epidermis, Cell wall, Membrane Lipids, 03 medical and health sciences, Cell Wall, Suberin, Arabidopsis thaliana, 030304 developmental biology, 0303 health sciences, Molecular Structure, Epidermis (botany), Fatty Acids, food and beverages, biology.organism_classification, Lipids, Models, Chemical, Biochemistry, Acyltransferases, Monoglycerides, Endodermis, Function (biology), 010606 plant biology & botany
Abstract: International audience; Cutin and suberin are insoluble lipid polymers that provide critical barrier functions to the cell wall of certain plant tissues, including the epidermis, endodermis and periderm. Genes that are specific to the biosynthesis of cutins and/or aliphatic suberins have been identified, mainly in Arabidopsis thaliana. They notably encode acyltransferases, oxidases and transporters, which may have either well-defined or more debatable biochemical functions. However, despite these advances, important aspects of cutin and suberin synthesis remain obscure. Central questions include whether fatty acyl monomers or oligomers are exported, and the extent of extracellular assembly and attachment to the cell wall. These issues are reviewed. Greater emphasis on chemistry and biochemistry will be required to solve these unknowns and link structure with function.
Published: 2012

44. Oil accumulation in the model green alga Chlamydomonas reinhardtii: characterization, variability between common laboratory strains and relationship with starch reserves

Author: Mai Nguyen, Patrick Carrier, Caroline Cagnon, Magali Siaut, Stéphan Cuiné, Gilles Peltier, Fred Beisson, Christian Triantaphylidès, Yonghua Li-Beisson, Audrey Beyly, Boris Fessler, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), ANR-06-BIOE-0013,DIVHYDO,Diversité des hydrogénases et de leur réactivité à l'oxygène(2006), ANR-08-BIOE-0002,ALGOMICS,ETUDES GLOBALES DE LA CONVERSION ET DU STOCKAGE DE L'ENERGIE CHEZ LES MICROALGUES(2008), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Chlorophyll, 0106 biological sciences, High Performance Thin Layer Chromatography Plate, Nitrogen, Starch, lcsh:Biotechnology, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, Sodium Chloride, Biology, Models, Biological, 01 natural sciences, Strain Cw15, Metabolic engineering, 03 medical and health sciences, chemistry.chemical_compound, High Performance Thin Layer Chromatography, Bioreactors, Microscopy, Electron, Transmission, lcsh:TP248.13-248.65, 010608 biotechnology, Oxazines, Microalgae, Triglycerides, 030304 developmental biology, 0303 health sciences, Biodiesel, Growth medium, Nitrogen deficiency, Fatty Acids, Chlamydomonas, biology.organism_classification, Biochemistry, chemistry, Research Article, Biotechnology
Abstract: Background When cultivated under stress conditions, many microalgae species accumulate both starch and oil (triacylglycerols). The model green microalga Chlamydomonas reinhardtii has recently emerged as a model to test genetic engineering or cultivation strategies aiming at increasing lipid yields for biodiesel production. Blocking starch synthesis has been suggested as a way to boost oil accumulation. Here, we characterize the triacylglycerol (TAG) accumulation process in Chlamydomonas and quantify TAGs in various wild-type and starchless strains. Results In response to nitrogen deficiency, Chlamydomonas reinhardtii produced TAGs enriched in palmitic, oleic and linoleic acids that accumulated in oil-bodies. Oil synthesis was maximal between 2 and 3 days following nitrogen depletion and reached a plateau around day 5. In the first 48 hours of oil deposition, a ~80% reduction in the major plastidial membrane lipids occurred. Upon nitrogen re-supply, mobilization of TAGs started after starch degradation but was completed within 24 hours. Comparison of oil content in five common laboratory strains (CC124, CC125, cw15, CC1690 and 11-32A) revealed a high variability, from 2 μg TAG per million cell in CC124 to 11 μg in 11-32A. Quantification of TAGs on a cell basis in three mutants affected in starch synthesis (cw15sta1-2, cw15sta6 and cw15sta7-1) showed that blocking starch synthesis did not result in TAG over-accumulation compared to their direct progenitor, the arginine auxotroph strain 330. Moreover, no significant correlation was found between cellular oil and starch levels among the twenty wild-type, mutants and complemented strains tested. By contrast, cellular oil content was found to increase steeply with salt concentration in the growth medium. At 100 mM NaCl, oil level similar to nitrogen depletion conditions could be reached in CC124 strain. Conclusion A reference basis for future genetic studies of oil metabolism in Chlamydomonas is provided. Results highlight the importance of using direct progenitors as control strains when assessing the effect of mutations on oil content. They also suggest the existence in Chlamydomonas of complex interplays between oil synthesis, genetic background and stress conditions. Optimization of such interactions is an alternative to targeted metabolic engineering strategies in the search for high oil yields.
Published: 2011

45. Proteomic profiling of oil bodies isolated from the unicellular green microalga Chlamydomonas reinhardtii: With focus on proteins involved in lipid metabolism

Author: Damien Barthe, Gilles Peltier, Stéphan Cuiné, Christophe Bruley, Emmanuelle Billon, Jean-Marc Adriano, Hoa M. Nguyen, Yonghua Li-Beisson, Myriam Ferro, Fred Beisson, Mathieu Baudet, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Proteomics, Proteome, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, 01 natural sciences, Biochemistry, 03 medical and health sciences, Oil body, Microalgae, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Plant Proteins, Organelles, 0303 health sciences, biology, Chlamydomonas, Lipid metabolism, Lipid signaling, biology.organism_classification, Lipid Metabolism, Acyltransferase, lipids (amino acids, peptides, and proteins), 010606 plant biology & botany
Abstract: Oil bodies are sites of energy and carbon storage in many organisms including microalgae. As a step toward deciphering oil accumulation mechanisms in algae, we used proteomics to analyze purified oil bodies from the model microalga Chlamydomonas reinhardtii grown under nitrogen deprivation. Among the 248 proteins (≥ 2 peptides) identified by LC-MS/MS, 33 were putatively involved in the metabolism of lipids (mostly acyl-lipids and sterols). Compared with a recently reported Chlamydomonas oil body proteome, 19 new proteins of lipid metabolism were identified, spanning the key steps of the triacylglycerol synthesis pathway and including a glycerol-3-phosphate acyltransferase (GPAT), a lysophosphatidic acid acyltransferase (LPAT) and a putative phospholipid:diacylglycerol acyltransferase (PDAT). In addition, proteins putatively involved in deacylation/reacylation, sterol synthesis, lipid signaling and lipid trafficking were found to be associated with the oil body fraction. This data set thus provides evidence that Chlamydomonas oil bodies are not only storage compartments but also are dynamic structures likely to be involved in processes such as oil synthesis, degradation and lipid homeostasis. The proteins identified here should provide useful targets for genetic studies aiming at increasing our understanding of triacyglycerol synthesis and the role of oil bodies in microalgal cell functions.
Published: 2011

46. Cutin and Suberin

Author: Yonghua Li-Beisson, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, chemistry.chemical_classification, 0303 health sciences, Materials science, Epidermis (botany), Cuticle, [SDV]Life Sciences [q-bio], food and beverages, Fatty acid, Cutin, 01 natural sciences, Cell wall, Polyester, 03 medical and health sciences, Biochemistry, chemistry, Suberin, Acyltransferases, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 010606 plant biology & botany
Abstract: Cutin and suberin are cell-wall associated glycerolipid polymers specific to plants. Cutin forms the framework of the cuticle sealing the aerial epidermis, whereas suberin is present in the periderm of barks and underground organs. Suberised walls are also found in root internal tissues. Barriers based on cutin and suberin restrict transport of water across cell walls and limit pathogen invasions. Chemical analysis shows that both polymers are polyesters composed mostly of C16-C18 hydroxyacids, diacids and epoxyacids esterified to each other and to glycerol. Suberin, whose best known form is cork, usually differs from cutin by a higher content in C20-C24 aliphatics and aromatics. In the last decade, the identification of Arabidopsis mutants affected in cutin or suberin content has allowed the identification of several proteins involved in polyester biosynthesis, including acyltransferases with unique specificities, fatty acid hydroxylases, acyl-CoA synthetases, fatty acid elongases and an ABC transporter. Key Concepts: The epidermal cells and suberising cells have specialised enzymes that convert the common cellular fatty acids into the unique components of cutin and suberin, respectively. Oxygenated fatty acid monomers are produced by fatty acid oxidases of the cytochrome P450 superfamily. Acylglycerol dimers can be synthesised by special glycerol-3-phosphate acyltransferases. Whether polymerisation of dimers and monomers occurs in intracellular compartments or in the cell walls is still unknown. How cutin and suberin polymers are linked to the cell walls remains to be determined. Cutin contributes to the formation of surface nanostructures in epidermis. Keywords: cutin; suberin; waxes; oxygenated fatty acids; glycerol-3-phosphate acyltransferase; P450 monooxygenase; cuticle; cork
Published: 2011

47. Cloning and molecular characterization of a glycerol-3-phosphate O-acyltransferase (GPAT) gene from Echium (Boraginaceae) involved in the biosynthesis of cutin polyesters

Author: Federico García-Maroto, Yonghua Li-Beisson, Diego López Alonso, Aurora Mañas-Fernández, Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Polyesters, [SDV]Life Sciences [q-bio], Plant Science, Cutin, 01 natural sciences, Polymerase Chain Reaction, Cell wall, 03 medical and health sciences, Membrane Lipids, Arabidopsis, Genetics, Arabidopsis thaliana, Echium, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, food and beverages, biology.organism_classification, Blotting, Southern, Biochemistry, Acyltransferase, Glycerol-3-Phosphate O-Acyltransferase, Ectopic expression, Heterologous expression, 010606 plant biology & botany
Abstract: The glycerol-based lipid polyester called cutin is a main component of cuticle, the protective interface of aerial plant organs also controlling compound exchange with the environment. Though recent progress towards understanding of cutin biosynthesis has been made in Arabidopsis thaliana, little is known in other plants. One key step in this process is the acyl transfer reaction to the glycerol backbone. Here we report the cloning and molecular characterization of EpGPAT1, a gene encoding a glycerol-3-phosphate O-acyltransferase (GPAT) from Echium pitardii (Boraginaceae) with high similarity to the AtGPAT4/AtGPAT8 of Arabidopsis. Quantitative analysis by qRT-PCR showed highest expression of EpGPAT1 in seeds, roots, young leaves and flowers. Acyltransferase activity of EpGPAT1 was evidenced by heterologous expression in yeast. Ectopic expression in leaves of tobacco plants lead to an increase of C16 and C18 hydroxyacids and alpha,omega-diacids in the cell wall fraction, indicating a role in the biosynthesis of polyesters. Analysis of the genomic organization in Echium revealed the presence of EpGPAT2, a closely related gene which was found to be mostly expressed in developing leaves and flowers. The presence of a conserved HAD-like domain at the N-terminal moiety of GPATs from Echium, Arabidopsis and other plant species suggests a possible phosphohydrolase activity in addition to the reported acyltransferase activity. Evolutive implications of this finding are discussed.
Published: 2010

48. A distinct type of glycerol-3-phosphate acyltransferase with sn-2 preference and phosphatase activity producing 2-monoacylglycerol

Author: John B. Ohlrogge, Michael Feig, Mike Pollard, Fred Beisson, Yonghua Li-Beisson, Weili Yang, Department of Plant Biology - Michigan State University, Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Department of Biochemistry and Molecular Biology, Michigan State University, and Department of Chemistry, Michigan State University
Subjects: Models, Molecular, 0106 biological sciences, Acylation, Membrane lipids, [SDV]Life Sciences [q-bio], Molecular Sequence Data, Phosphatase, Arabidopsis, Saccharomyces cerevisiae, Cutin, Biology, Genes, Plant, 01 natural sciences, Substrate Specificity, Evolution, Molecular, Membrane Lipids, 03 medical and health sciences, chemistry.chemical_compound, Biosynthesis, Suberin, Amino Acid Sequence, Triticum, ComputingMilieux_MISCELLANEOUS, DNA Primers, 030304 developmental biology, 0303 health sciences, Multidisciplinary, Base Sequence, Sequence Homology, Amino Acid, Arabidopsis Proteins, food and beverages, Biological Sciences, Lipids, Recombinant Proteins, Monoacylglycerol lipase, Amino Acid Substitution, Biochemistry, chemistry, Acyltransferases, Glycerol-3-Phosphate O-Acyltransferase, Mutagenesis, Site-Directed, Monoglycerides, lipids (amino acids, peptides, and proteins), Mutant Proteins, 010606 plant biology & botany
Abstract: The first step in assembly of membrane and storage glycerolipids is acylation of glycerol-3-phosphate (G3P). All previously characterized membrane-bound, eukaryotic G3P acyltransferases (GPATs) acylate the sn -1 position to produce lysophosphatidic acid (1-acyl-LPA). Cutin is a glycerolipid with omega-oxidized fatty acids and glycerol as integral components. It occurs as an extracellular polyester on the aerial surface of all plants, provides a barrier to pathogens and resistance to stress, and maintains organ identity. We have determined that Arabidopsis acyltransferases GPAT4 and GPAT6 required for cutin biosynthesis esterify acyl groups predominantly to the sn -2 position of G3P. In addition, these acyltransferases possess a phosphatase domain that results in sn -2 monoacylglycerol (2-MAG) rather than LPA as the major product. Such bifunctional activity has not been previously described in any organism. The possible roles of 2-MAGs as intermediates in cutin synthesis are discussed. GPAT5, which is essential for the accumulation of suberin aliphatics, also exhibits a strong preference for sn -2 acylation. However, phosphatase activity is absent and 2-acyl-LPA is the major product. Clearly, plant GPATs can catalyze more reactions than the sn -1 acylation by which they are currently categorized. Close homologs of GPAT4-6 are present in all land plants, but not in animals, fungi or microorganisms (including algae). Thus, these distinctive acyltransferases may have been important for evolution of extracellular glycerolipid polymers and adaptation of plants to a terrestrial environment. These results provide insight into the biosynthetic assembly of cutin and suberin, the two most abundant glycerolipid polymers in nature.
Published: 2010

49. Nanoridges that characterize the surface morphology of flowers require the synthesis of cutin polyester

Author: Franck Pinot, Vincent Sauveplane, John B. Ohlrogge, Yonghua Li-Beisson, Mike Pollard, Fred Beisson, Department of Plant Biology - Michigan State University, Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Institut de biologie moléculaire des plantes (IBMP), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire de biogenèse membranaire (LBM), and Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Cuticle, Polyesters, [SDV]Life Sciences [q-bio], Mutant, Arabidopsis, Cutin, Flowers, Biology, 01 natural sciences, 03 medical and health sciences, Membrane Lipids, CYP77A6, Cytochrome P-450 Enzyme System, Acetyltransferases, Arabidopsis thaliana, Nanotechnology, 10 16-dihydroxypalmitic acid, glycerol-3-phosphate acyltransferase 6, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, cuticular ridges, 0303 health sciences, Multidisciplinary, fungi, food and beverages, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Biological Sciences, biology.organism_classification, Biochemistry, Acyltransferase, CYP86A4, Mutation, Petal, Function (biology), 010606 plant biology & botany
Abstract: Distinctive nanoridges on the surface of flowers have puzzled plant biologists ever since their discovery over 75 years ago. Although postulated to help attract insect pollinators, the function, chemical nature, and ontogeny of these surface nanostructures remain uncertain. Studies have been hampered by the fact that no ridgeless mutants have been identified. Here, we describe two mutants lacking nanoridges and define the biosynthetic pathway for 10,16-dihydroxypalmitate, a major cutin monomer in nature. Using gene expression profiling, two candidates for the formation of floral cutin were identified in the model plant Arabidopsis thaliana : the glycerol-3-phosphate acyltransferase 6 (GPAT6) and a member of a cytochrome P450 family with unknown biological function (CYP77A6). Plants carrying null mutations in either gene produced petals with no nanoridges and no cuticle could be observed by either scanning or transmission electron microscopy. A strong reduction in cutin content was found in flowers of both mutants. In planta overexpression suggested GPAT6 preferentially uses palmitate derivatives in cutin synthesis. Comparison of cutin monomer profiles in knockouts for CYP77A6 and the fatty acid ω-hydroxylase CYP86A4 provided genetic evidence that CYP77A6 is an in-chain hydroxylase acting subsequently to CYP86A4 in the synthesis of 10,16-dihydroxypalmitate. Biochemical activity of CYP77A6 was demonstrated by production of dihydroxypalmitates from 16-hydroxypalmitate, using CYP77A6 -expressing yeast microsomes. These results define the biosynthetic pathway for an abundant and widespread monomer of the cutin polyester, show that the morphology of floral surfaces depends on the synthesis of cutin, and identify target genes to investigate the function of nanoridges in flower biology.
Published: 2009

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