Search

Your search keyword '"Bernard Genty"' showing total 10 results
Start Over Author "Bernard Genty" Publisher hal ccsd
10 results on '"Bernard Genty"'

1. Estimating Mesophyll Conductance from Measurements of C 18 OO Photosynthetic Discrimination and Carbonic Anhydrase Activity

Author

Lisa Wingate, Bernard Genty, Jérôme Ogée, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), 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), Protéines de Protection des Végétaux (PPV), 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)), Photosynthèse & Environnement (P&E), ANR-13-BS06-0005,ORCA,Etude des mécanismes de régulation de l'anhydrase carbonique et des flux de COS et CO18O dans les écosystèmes terrestres(2013), European Project: 1338264(2013), European Project: 0400539(2004), European Project: 618105, 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'Ecophysiologie Moléculaire des Plantes (LEMP), Interactions Sol Plante Atmosphère (ISPA), 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, biology, Physiology, Chemistry, [SDV]Life Sciences [q-bio], Conductance, Plant physiology, Plant Science, Vascular bundle, Photosynthesis, 01 natural sciences, 03 medical and health sciences, Light intensity, 030104 developmental biology, Carbonic anhydrase, Respiration, Genetics, Biophysics, biology.protein, Respiration rate, ComputingMilieux_MISCELLANEOUS, 010606 plant biology & botany
Abstract

International audience; Carbonic anhydrase (CA) activity in leaves catalyzes the O-18 exchange between CO2 and water during photosynthesis. This feature has been used to estimate the mesophyll conductance to CO2 (g(m)) from measurements of online (COO)-O-18 photosynthetic discrimination (Delta O-18) Based on CA assays on leaf extracts, it has been argued that CO2 in mesophyll cells should be in isotopic equilibrium with water in most C-3 species as well as many C-4 dicot species. However, this seems incompatible with Delta O-18 data that would indicate a much lower degree of equilibration, especially in C-4 plants under high light intensity. This apparent contradiction is resolved here using a new model of C-3 and C-4 photosynthetic discrimination that includes competition between CO2 hydration and carboxylation and the contribution of respiratory fluxes. This new modeling framework is used to revisit previously published data sets on C-3 and C-4 species, including CA-deficient plants. We conclude that (1) newly Delta O-18-derived g(m) values are usually close but significantly higher (typically 20% and up to 50%) than those derived assuming full equilibration and (2) despite the uncertainty associated with the respiration rate in light, or the water isotope gradient between mesophyll and bundle sheath cells, robust estimates of Delta O-18-derived g(m) can be achieved in both C-3 and C-4 plants.

Published
2018
Full Text
View/download PDF

2. Actin filament reorganisation controlled by the SCAR/WAVE complex mediates stomatal response to darkness

Author

Kun Jiang, Bernard Genty, Alistair M. Hetherington, Fabien Monnet, Xiaobin Ou, Zaoxu Xu, Joaquim Miguel Costa, Thomas E Batstone, Jean-Charles Isner, Michael J. Deeks, School of Biological Sciences [Bristol], University of Bristol [Bristol], Zhejiang University, 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), Laboratoire d'Ecophysiologie Moléculaire des Plantes (LEMP), University of Exeter, Laboratoire d'Excellence 'Maîtrise des Systèmes de Systèmes Technologiques' (Labex MS2T), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), European Project: HNRT‐CT‐2002‐00254,STRESSIMAGING, 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), Protéines de Protection des Végétaux (PPV), 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 Photosynthèse & Environnement (P&E)

Subjects
0301 basic medicine, Physiology, [SDV]Life Sciences [q-bio], Arabidopsis, Arp2/3 complex, Plant Science, Microfilament, chemistry.chemical_compound, Calcium Chloride, darkness, Guard cell, Cytoskeleton, ComputingMilieux_MISCELLANEOUS, Cytochalasin D, biology, Full Paper, Darkness, Full Papers, Cell biology, Actin Cytoskeleton, Phenotype, Thiazolidines, macromolecular substances, Genes, Plant, Filamentous actin, Models, Biological, Actin-Related Protein 2-3 Complex, 03 medical and health sciences, Botany, Alleles, Stomata, Base Sequence, Arabidopsis Proteins, Research, Actin cytoskeleton, Bridged Bicyclo Compounds, Heterocyclic, Protein Subunits, 030104 developmental biology, chemistry, Multiprotein Complexes, Mutation, Plant Stomata, actin filaments, biology.protein, SCAR/WAVE complex, Actin filaments, Abscisic Acid
Abstract

Stomata respond to darkness by closing to prevent excessive water loss during the night. Although the reorganisation of actin filaments during stomatal closure is documented, the underlying mechanisms responsible for dark-induced cytoskeletal arrangement remain largely unknown. We used genetic, physiological and cell biological approaches to show that reorganisation of the actin cytoskeleton is required for dark-induced stomatal closure. The opal5 mutant does not close in response to darkness but exhibits wild-type (WT) behaviour when exposed to abscisic acid (ABA) or CaCl2. The mutation was mapped to At5g18410, encoding the PIR/SRA1/KLK subunit of the ArabidopsisSCAR/WAVE complex. Stomata of an independent allele of the PIR gene (Atpir-1) showed reduced sensitivity to darkness and F1 progenies of the cross between opal5 and Atpir-1 displayed distorted leaf trichomes, suggesting that the two mutants are allelic. Darkness induced changes in the extent of actin filament bundling in WT. These were abolished in opal5. Disruption of filamentous actin using latrunculin B or cytochalasin D restored wild-type stomatal sensitivity to darkness in opal5. Our findings suggest that the stomatal response to darkness is mediated by reorganisation of guard cell actin filaments, a process that is finely tuned by the conserved SCAR/WAVE–Arp2/3 actin regulatory module.

Published
2017
Full Text
View/download PDF

3. Bryophyte gas-exchange dynamics along varying hydration status reveal a significant carbonyl sulphide (COS) sink in the dark and COS source in the light

Author

Jérôme Ogée, Sam P. Jones, Camille Bénard, Joana Sauze, Teresa E. Gimeno, Yves Gibon, Jessica Royles, Jason B. West, Lisa Wingate, Régis Burlett, Bernard Genty, Steven Wohl, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Department Plant Sciences, University of Cambridge, Biologie du fruit et pathologie (BFP), Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1, Department of Ecosystem Science & Management, Texas A&M University System, Biodiversité, Gènes & Communautés (BioGeCo), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB), 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), Laboratoire d'Ecophysiologie Moléculaire des Plantes (LEMP), Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1 (UB), 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), Protéines de Protection des Végétaux (PPV), 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)), Photosynthèse & Environnement (P&E), ANR-13-BS06-0005,ORCA,Etude des mécanismes de régulation de l'anhydrase carbonique et des flux de COS et CO18O dans les écosystèmes terrestres(2013), European Project: 338264,EC:FP7:ERC,ERC-2013-StG,SOLCA(2014), Interactions Sol Plante Atmosphère (ISPA), Université Sciences et Technologies - Bordeaux 1-Institut National de la Recherche Agronomique (INRA)-Université Bordeaux Segalen - Bordeaux 2, Biodiversité, Gènes et Communautés, 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)), 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)), Evans, Jessica [0000-0003-0489-6863], and Apollo - University of Cambridge Repository

Subjects
0106 biological sciences, Light, 010504 meteorology & atmospheric sciences, Physiology, marchantia polymorpha, [SDV]Life Sciences [q-bio], carbonic anhydrase, Sulfur Oxides, carbohydrates, Bryophyta, Plant Science, 01 natural sciences, Article, moss, desiccation, liverwort, Political science, Early career, anhydrase carbonique, Plant Proteins, 0105 earth and related environmental sciences, Hydration status, Full Paper, Ecology, Research, European research, Scleropodium purum, Temperature, Water, Forestry, Darkness, Full Papers, 15. Life on land, 3. Good health, Plant Leaves, sulfure de carbonyle, 13. Climate action, Gases, protein, respiration, 010606 plant biology & botany
Abstract

Summary Carbonyl sulphide (COS) is a potential tracer of gross primary productivity (GPP), assuming a unidirectional COS flux into the vegetation that scales with GPP. However, carbonic anhydrase (CA), the enzyme that hydrolyses COS, is expected to be light independent, and thus plants without stomata should continue to take up COS in the dark.We measured net CO 2 (AC) and COS (AS) uptake rates from two astomatous bryophytes at different relative water contents (RWCs), COS concentrations, temperatures and light intensities.We found large AS in the dark, indicating that CA activity continues without photosynthesis. More surprisingly, we found a nonzero COS compensation point in light and dark conditions, indicating a temperature‐driven COS source with a Q 10 (fractional change for a 10°C temperature increase) of 3.7. This resulted in greater AS in the dark than in the light at similar RWC. The processes underlying such COS emissions remain unknown.Our results suggest that ecosystems dominated by bryophytes might be strong atmospheric sinks of COS at night and weaker sinks or even sources of COS during daytime. Biotic COS production in bryophytes could result from symbiotic fungal and bacterial partners that could also be found on vascular plants., See also the Commentary on this article by Wohlfahrt, 215: 923–925.

Published
2017
Full Text
View/download PDF

4. The dual effect of abscisic acid on stomata

Author

Thierry Simonneau, Dorothée Jannaud, Joaquim Miguel Costa, Fabien Monnet, Bertrand Muller, Bernard Genty, Jeanne Renaud, Florent Pantin, Écophysiologie des Plantes sous Stress environnementaux (LEPSE), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro), 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, Stomatal conductance, anisohydric, Arabidopsis thaliana, Physiology, hydraulic conductance (Kleaf), isohydric, Mutant, Arabidopsis, Plant Science, 01 natural sciences, Plant Epidermis, transpiration, 03 medical and health sciences, chemistry.chemical_compound, Plant Cells, Guard cell, Botany, Phosphoprotein Phosphatases, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Argon, Abscisic acid, Vascular tissue, 030304 developmental biology, Transpiration, 0303 health sciences, biology, Epidermis (botany), leaf, Arabidopsis Proteins, organic chemicals, fungi, Water, food and beverages, stomatal conductance (gs), Biological Transport, Plant Transpiration, aquaporin (PIP), biology.organism_classification, Droughts, Plant Leaves, chemistry, ABA, Mutation, Plant Stomata, Abscisic Acid, 010606 plant biology & botany
Abstract

International audience; The classical view that the drought-related hormone ABA simply acts locally at the guard cell level to induce stomatal closure is questioned by differences between isolated epidermis and intact leaves in stomatal response to several stimuli. We tested the hypothesis that ABA mediates, in addition to a local effect, a remote effect in planta by changing hydraulic regulation in the leaf upstream of the stomata. By gravimetry, porometry to water vapour and argon, and psychrometry, we investigated the effect of exogenous ABA on transpiration, stomatal conductance and leaf hydraulic conductance of mutants described as ABA-insensitive at the guard cell level. We show that foliar transpiration of several ABA-insensitive mutants decreases in response to ABA. We demonstrate that ABA decreases stomatal conductance and down-regulates leaf hydraulic conductance in both the wildtype Col-0 and the ABA-insensitive mutant ost2-2. We propose that ABA promotes stomatal closure in a dual way via its already known biochemical effect on guard cells and a novel, indirect hydraulic effect through a decrease in water permeability within leaf vascular tissues. Variability in sensitivity of leaf hydraulic conductance to ABA among species could provide a physiological basis to the isohydric or anisohydric behaviour.

Published
2013
Full Text
View/download PDF

5. Control of Hydrogen Photoproduction by the Proton Gradient Generated by Cyclic Electron Flow in Chlamydomonas reinhardtii

Author

Audrey Beyly, Danuta Krawietz, Irina Tolstygina, Bernard Genty, Bart Ghysels, Laurent Cournac, Pascaline Auroy, Ilja M. Reiter, Dimitri Tolleter, Julie Plet, Thomas Happe, Michael Hippler, Stéphan Cuiné, Gilles Peltier, Dimitris Petroutsos, Jean Alric, Jean-Marc Adriano, 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)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA, DSV, IBEB, SBVME, Laboratoire d’Ecophysiologie Moléculaire des Plantes, 13108 Saint-Paul-lez-Durance, Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Ruhr University Bochum (RUB), ANR-08-BIOE-0002,ALGOMICS,ETUDES GLOBALES DE LA CONVERSION ET DU STOCKAGE DE L'ENERGIE CHEZ LES MICROALGUES(2008), European Project: 516510 ,SOLAR-H, European Project: 212508,EC:FP7:ENERGY,FP7-ENERGY-2007-1-RTD,SOLARH2(2008), and European Project: 245070,EC:FP7:KBBE,FP7-KBBE-2009-3,SUNBIOPATH(2010)

Subjects
0106 biological sciences, Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone, Hydrogenase, Hydrogen, Light, Cellular respiration, [SDV]Life Sciences [q-bio], Chlamydomonas reinhardtii, chemistry.chemical_element, Electrons, Plant Science, Biology, Photosystem I, 01 natural sciences, Electron Transport, 03 medical and health sciences, Anaerobiosis, Photosynthesis, Electrochemical gradient, Chlorophyll fluorescence, Research Articles, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Plant Proteins, 0303 health sciences, Quenching (fluorescence), Photosystem I Protein Complex, Genetic Complementation Test, Membrane Proteins, Cell Biology, biology.organism_classification, Plants, Genetically Modified, Aerobiosis, Oxygen, chemistry, Biochemistry, Biophysics, Proton Ionophores, Protons, Oxidation-Reduction, Sulfur, 010606 plant biology & botany
Abstract

International audience; Hydrogen photoproduction by eukaryotic microalgae results from a connection between the photosynthetic electron transport chain and a plastidial hydrogenase. Algal H$_2$ production is a transitory phenomenon under most natural conditions, often viewed as a safety valve protecting the photosynthetic electron transport chain from overreduction. From the colony screening of an insertion mutant library of the unicellular green alga Chlamydomonas reinhardtii based on the analysis of dark-light chlorophyll fluorescence transients, we isolated a mutant impaired in cyclic electron flow around photosystem I (CEF) due to a defect in the Proton Gradient Regulation Like1 (PGRL1) protein. Under aerobiosis, nonphotochemical quenching of fluorescence (NPQ) is strongly decreased in pgrl1. Under anaerobiosis, H$_2$ photoproduction is strongly enhanced in the pgrl1 mutant, both during short-term and long-term measurements (in conditions of sulfur deprivation). Based on the light dependence of NPQ and hydrogen production, as well as on the enhanced hydrogen production observed in the wild-type strain in the presence of the uncoupling agent carbonyl cyanide p-trifluoromethoxyphenylhydrazone, we conclude that the proton gradient generated by CEF provokes a strong inhibition of electron supply to the hydrogenase in the wild-type strain, which is released in the pgrl1 mutant. Regulation of the trans-thylakoidal proton gradient by monitoring pgrl1 expression opens new perspectives toward reprogramming the cellular metabolism of microalgae for enhanced H$_2$ production.

Published
2011
Full Text
View/download PDF

6. The cytosolic/nuclear HSC70 and HSP90 molecular chaperones are important for stomatal closure and modulate abscisic acid-dependent physiological responses in Arabidopsis

Author

Marie-Jo Droillard, Nathalie Leonhardt, Bernard Genty, Laurent D. Noël, Mathilde Clément, Christiane Laurière, Ilja M. Reiter, Jean-Luc Montillet, Laurent Nussaume, Université de la Méditerranée - Aix-Marseille 2, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut des sciences du végétal (ISV), Institut National de la Recherche Agronomique (INRA), Université Paris Diderot - Paris 7 (UPD7), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), 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), UPR2355 Institut des sciences du végétal, Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), 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 mixte de recherche interactions plantes-microorganismes, Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Commissariat a l'Energie Atomique, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Plant Environmental Physiology and Stress Signaling (PEPSS), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, CYTOSOL, Transcription, Genetic, NODULATION, Physiology, CRUCIFERAE, ANGIOSPERMAE, Arabidopsis, Plant Science, 01 natural sciences, ABSCISIC ACID, chemistry.chemical_compound, Gene Expression Regulation, Plant, santé des plantes, Génétique des plantes, Abscisic acid, SESQUITERPENES, Adenosine Triphosphatases, Abiotic component, CHAPERONE, 0303 health sciences, SPERMATOPHYTA, Dehydration, biology, PLANT GROWTH SUBSTANCE, food and beverages, Darkness, Hsp90, PHYSIOLOGICAL PARAMETER, Biochemistry, Seeds, MOLECULAR DOMAIN, STOMATAL CONDUCTANCE, génétique moléculaire, Germination, Environmental Stress and Adaptation to Stress, macromolecular substances, Plants genetics, Genes, Plant, [SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics, 03 medical and health sciences, Heat shock protein, Genetics, STOMATAL MOVEMENT, HSP90 Heat-Shock Proteins, RELATION PLANTE-MICROORGANISME, 030304 developmental biology, Cell Nucleus, DICOTYLEDONE, Arabidopsis Proteins, Abiotic stress, fungi, HSC70 Heat-Shock Proteins, ARABIDOPSIS THALIANA, biology.organism_classification, EXPERIMENTAL PLANT, PLANT PHYSIOLOGY, UNCTIONAL RESPONSE, chemistry, Chaperone (protein), Mutation, Plant Stomata, biology.protein, Peptides, Flagellin, 010606 plant biology & botany
Abstract

L'article original est publié par The American Society of Plant Biologists; International audience; Cytosolic/nuclear molecular chaperones of the heat shock protein families HSP90 and HSC70 are conserved and essential proteins in eukaryotes. These proteins have essentially been implicated in the innate immunity and abiotic stress tolerance in higher plants. Here, we demonstrate that both chaperones are recruited in Arabidopsis (Arabidopsis thaliana) for stomatal closure induced by several environmental signals. Plants overexpressing HSC70-1 or with reduced HSP90.2 activity are compromised in the dark-, CO2-, flagellin 22 peptide-, and abscisic acid (ABA)-induced stomatal closure. HSC70-1 and HSP90 proteins are needed to establish basal expression levels of several ABA-responsive genes, suggesting that these chaperones might also be involved in ABA signaling events. Plants overexpressing HSC70-1 or with reduced HSP90.2 activity are hypersensitive to ABA in seed germination assays, suggesting that several chaperone complexes with distinct substrates might tune tissue-specific responses to ABA and the other biotic and abiotic stimuli studied. This study demonstrates that the HSC70/HSP90 machinery is important for stomatal closure and serves essential functions in plants to integrate signals from their biotic and abiotic environments.

Published
2011
Full Text
View/download PDF

7. Elevated Expression of PGR5 and NDH-H in Bundle Sheath Chloroplasts in C4Flaveria Species

Author

Dominique Rumeau, Masateru Oguri, Bernard Genty, Yuri Munekage, Gilles Peltier, Akiho Yokota, Stéphan Cuiné, Françoise Eymery, Naoya Nakamura, 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, Flaveria, Chloroplasts, Physiology, [SDV]Life Sciences [q-bio], Immunoblotting, Plant Science, Photosynthesis, 01 natural sciences, Electron Transport, 03 medical and health sciences, Gene Expression Regulation, Plant, Electrochemical gradient, C4 photosynthesis, ComputingMilieux_MISCELLANEOUS, Plant Proteins, 030304 developmental biology, 0303 health sciences, biology, Cell Biology, General Medicine, Vascular bundle, biology.organism_classification, Electron transport chain, Chloroplast, Biochemistry, Biophysics, NAD+ kinase, 010606 plant biology & botany
Abstract

Cyclic electron transport around PSI has been proposed to supply the additional ATP required for C(4) photosynthesis. To investigate the nature of cyclic electron pathways involved in C(4) photosynthesis, we analyzed tissue-specific expression of PGR5 (PROTON GRADIENT REGULATION 5), which is involved in the antimycin A-sensitive pathway, and NDH-H, a subunit of the plastidial NAD(P)H dehydrogenase complex, in four Flaveria species comprising NADP-malic enzyme (ME)-type C(4), C(3)-C(4) intermediate and C(3) species. PGR5 was highly expressed in the C(4) species and enriched in bundle sheath chloroplasts together with NDH-H, suggesting that electron transport of both PGR5-dependent and NDH-dependent cyclic pathways is promoted to drive C(4) photosynthesis.

Published
2010
Full Text
View/download PDF

8. The impact of soil microorganisms on the global budget of δ18O in atmospheric CO2

Author

Behzad Mortazavi, Bernard Genty, Kadmiel Maseyk, Lisa Wingate, Ilja M. Reiter, Elise Pendall, Dan Yakir, Margaret M. Barbour, Matthias Cuntz, Philippe Peylin, Régis Burlett, Jee H. Shim, John Grace, John B. Miller, Jérôme Ogée, Maurizio Mencuccini, Ulli Seibt, John Hunt, Écologie fonctionnelle et physique de l'environnement (EPHYSE), Institut National de la Recherche Agronomique (INRA), School of GeoSciences, University of Edinburgh, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, 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), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Weizmann Institute of Science [Rehovot, Israël], Department of Botany, University of Wyoming (UW), Manaaki Whenua – Landcare Research [Lincoln], Department of Biological Sciences, University of Alabama [Tuscaloosa] (UA), Dauphin Island Sea Lab, University of South Alabama, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Colorado State University [Fort Collins] (CSU), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
cycle du carbone, 010504 meteorology & atmospheric sciences, δ18O, cycle de l'eau, Climate Change, [SDE.MCG]Environmental Sciences/Global Changes, Population, carbonic anhydrase, water cycle, Photosynthesis, 01 natural sciences, Models, Biological, Atmosphere, chemistry.chemical_compound, Flux (metallurgy), carbon cycle, education, Milieux et Changements globaux, isotope, Soil Microbiology, 0105 earth and related environmental sciences, Carbonic Anhydrases, education.field_of_study, Multidisciplinary, Chemistry, oxygen isotopes, 04 agricultural and veterinary sciences, Carbon Dioxide, terrestrial biosphere, 13. Climate action, Environmental chemistry, Soil water, Carbon dioxide, Physical Sciences, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Seasons, Soil microbiology
Abstract

Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO 2 . The oxygen isotopic composition of atmospheric CO 2 can be used to estimate these fluxes because oxygen isotopic exchange between CO 2 and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report widespread accelerated soil CO 2 hydration. Exchange was 10–300 times faster than the uncatalyzed rate, consistent with typical population sizes for CA-containing soil microorganisms. Including accelerated soil hydration in global model simulations modifies contributions from soil and foliage to the global CO 18 O budget and eliminates persistent discrepancies existing between model and atmospheric observations. This enhanced soil hydration also increases the differences between the isotopic signatures of photosynthesis and respiration, particularly in the tropics, increasing the precision of CO 2 gross fluxes obtained by using the δ 18 O of atmospheric CO 2 by 50%.

Published
2009
Full Text
View/download PDF

9. Vitamin E is essential for the tolerance of Arabidopsis thaliana to metal-induced oxidative stress

Author

Françoise Eymery, Pascal Rey, Michel Havaux, Bernard Genty, Valérie Collin, 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), 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, Antioxidant, Physiology, medicine.medical_treatment, Blotting, Western, Arabidopsis, Tocopherols, Plant Science, Ascorbic Acid, medicine.disease_cause, 01 natural sciences, Antioxidants, Lipid peroxidation, 03 medical and health sciences, chemistry.chemical_compound, Gene Expression Regulation, Plant, Malondialdehyde, medicine, Arabidopsis thaliana, Vitamin E, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, RNA, Messenger, Intramolecular Transferases, Chromatography, High Pressure Liquid, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Arabidopsis Proteins, food and beverages, Glutathione, Ascorbic acid, biology.organism_classification, beta Carotene, Adaptation, Physiological, Phosphoric Monoester Hydrolases, Oxidative Stress, chemistry, Biochemistry, Luminescent Measurements, Mutation, Lipid Peroxidation, Oxidative stress, Copper, 010606 plant biology & botany, Cadmium
Abstract

Arabidopsis (Arabidopsis thaliana) plants were grown in a hydroponic culture system for 7 to 14 d in the absence or presence of 75 microM Cd or 75 microM Cu. The Cu treatment resulted in visual leaf symptoms, together with anthocyanin accumulation and loss of turgor. Pronounced lipid peroxidation, which was detected by autoluminescence imaging and malondialdehyde titration, was observed in Cu-treated leaves. The Cd treatment also resulted in loss of leaf pigments but lipid peroxidation and oxidative stress were less pronounced than in the leaves exposed to Cu. Analysis of low-molecular-weight chloroplast and cytosolic antioxidants (ascorbate, glutathione, tocopherols, carotenoids) and antioxidant enzymes (thiol-based reductases and peroxidases) revealed relatively few responses to metal exposure. However, there was a marked increase in vitamin E (alpha-tocopherol) in response to Cd and Cu treatments. Ascorbate increased significantly in Cu-exposed leaves. Other antioxidants either remained stable or decreased in response to metal stress. Transcripts encoding enzymes of the vitamin E biosynthetic pathway were increased in response to metal exposure. In particular, VTE2 mRNA was enhanced in Cu- and Cd-treated plants, while VTE5 and hydroxylpyruvate dioxygenase (HPPD) mRNAs were only up-regulated in Cd-treated plants. Consistent increases in HPPD transcripts and protein were observed. The vitamin E-deficient (vte1) mutant exhibited an enhanced sensitivity towards both metals relative to the wild-type (WT) control. Unlike the vte1 mutants, which showed enhanced lipid peroxidation and oxidative stress in the presence of Cu or Cd, the ascorbate-deficient (vtc2) mutant showed WT responses to metal exposure. Taken together, these results demonstrate that vitamin E plays a crucial role in the tolerance of Arabidopsis to oxidative stress induced by heavy metals such as Cu and Cd.

Published
2007
Full Text
View/download PDF

10. Use of infrared thermal imaging to isolate Arabidopsis mutants defective in stomatal regulation

Author

Jérôme Giraudat, Valérie Lefebvre, Bernard Genty, Sylvain Merlot, Helen M. North, Anna-Chiara Mustilli, Bruno Sotta, Alain Vavasseur, Institut des sciences du végétal (ISV), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecophysiologie Végétale, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Biologie des Semences (LBS), Institut National de la Recherche Agronomique (INRA)-Institut National Agronomique Paris-Grignon (INA P-G), Physiologie cellulaire et moléculaire des plantes (PCMP), Université Pierre et Marie Curie - Paris 6 (UPMC)-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), Université Paris-Sud - Paris 11 (UP11), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2

Subjects
0106 biological sciences, MESH: Body Temperature, Mutant, Arabidopsis, Plant Science, 01 natural sciences, Body Temperature, chemistry.chemical_compound, Guard cell, MESH: Genes, Plant, Arabidopsis thaliana, MESH: Arabidopsis, Abscisic acid, Transpiration, 0303 health sciences, biology, food and beverages, Cell biology, Complementation, MESH: Plant Leaves, Thermography, MESH: Desiccation, MESH: Infrared Rays, MESH: Mutation, Infrared Rays, Genes, Plant, [SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics, 03 medical and health sciences, Botany, Genetics, MESH: Water, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Desiccation, Alleles, 030304 developmental biology, MESH: Alleles, fungi, Wild type, Water, Cell Biology, Plant, biology.organism_classification, Plant Leaves, chemistry, Genes, ACIDE ABSCISSIQUE, Mutation, MESH: Abscisic Acid, MESH: Thermography, 010606 plant biology & botany, Abscisic Acid
Abstract

In response to drought, plants synthesise the hormone abscisic acid (ABA), which triggers closure of the stomatal pores. This process is vital for plants to conserve water by reducing transpirational water loss. Moreover, recent studies have demonstrated the advantages of the Arabidopsis stomatal guard cell for combining genetic, molecular and biophysical approaches to characterise ABA action. However, genetic dissection of stomatal regulation has been limited by the difficulty of identifying a reliable phenotype for mutant screening. Leaf temperature can be used as an indicator to detect mutants with altered stomatal control, since transpiration causes leaf cooling. In this study, we optimised experimental conditions under which individual Arabidopsis plants with altered stomatal responses to drought can be identified by infrared thermography. These conditions were then used to perform a pilot screen for mutants that displayed a reduced ability to close their stomata and hence appeared colder than the wild type. Some of the mutants recovered were deficient in ABA accumulation, and corresponded to alleles of the ABA biosynthesis loci ABA1, ABA2 and ABA3. Interestingly, two of these novel aba2 alleles were able to intragenically complement the aba2-1 mutation. The remaining mutants showed reduced ABA responsiveness in guard cells. In addition to the previously known abi1-1 mutation, we isolated mutations at two novel loci designated as OST1 (OPEN STOMATA 1) and OST2. Remarkably, ost1 and ost2 represent, to our knowledge, the first Arabidopsis mutations altering ABA responsiveness in stomata and not in seeds.

Published
2002
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results