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Dichlorodiphenyl-trichloroethane (DDT) and permethrin (PMT) are amongst most prevalent pesticides in the environment. Although their toxicity has been extensively studied, molecular mechanisms and metabolic effects remain unclear, including in liver where their detoxification occurs. Here, we used metabolomics, coupled to RT-qPCR analysis, to examine effects of DDT and PMT on hepatocytes cultivated in biochips. At 150 μM, DDT caused cell death, cytochrome P450 induction and modulation of estrogen metabolism. Metabolomics analysis showed an increase in some lipids and sugars after 6 h, and a decrease in fatty acids (tetradecanoate, octanoate and linoleate) after 24 h exposure. We also found a change in expression associated with genes involved in hepatic estrogen, lipid, and sugar metabolism. PMT at 150 μM perturbed lipid/sugar homeostasis and estrogen signaling pathway, between 2 and 6 h. After 24 h, lipids and sugars were found to decrease, suggesting continuous energy demand to detoxify PMT. Finally, at 15 μM, DDT and PMT appeared to have a small effect on metabolism and were detoxified after 24 h. Our results show a time-dependent perturbation of sugar/lipid homeostasis by DDT and PMT at 150 μM. Furthermore, DDT at high dose led to cell death, inflammatory response and oxidative stress. [ABSTRACT FROM AUTHOR]

• Induced pluripotent stem cells iPSC differentiation to hepatocytes was characterized. • Two protocols were studied and compared to reduce the cost of differentiation. • Metabolomics analyses were coupled with Cap Analysis Gene Expression (nanoCAGE). • Hepatic phenotype was confirmed in both protocols by albumin and urea production. • Omics analyses explained iPSC metabolism during step-by-step differentiation. Human hepatocyte-like cells derived from human induced pluripotent stem cells (hiPSC) may provide an unlimited supply of cells for in vitro liver models. However, hiPSC differentiation remains a major challenge due to immaturity of the hepatocytes obtained and the high cost of differentiation protocols currently proposed. Here, we studied the efficacy of new protocol, with reduction of growth factors, for the generation of hepatocyte-like cells from hiPSC. We performed metabolomic and mRNA analysis by RTqPCR and nanoCAGE processing to identify and understand key metabolisms during differentiation. By reducing the change frequency of the culture medium in the new protocol, we successfully generated hepatocyte-like cells producing albumin, urea, and CYP3A4 positive. The metabolomic analysis successfully extracted both signatures, common and specific, for each differentiation step. Integrating the metabolomic data with transcriptomic contributed to explaining the kinetics of carbohydrate, lipid and nitrogen metabolism throughout differentiation. The information extracted during differentiation showed that the cells moved from an aerobic-like respiration pattern to a mitochondrial oxidative respiration pattern in both protocols. Reducing culture medium renewal led to reduced glucose consumption, followed by fructose production and significant extracellular lipogenesis throughout differentiation. We believe that the overall dataset can provide information on the sequence of process. [ABSTRACT FROM AUTHOR]

Thioredoxins f (Trx f ) are chloroplastic proteins that have been shown to be essential for the redox-based regulation of several steps of carbon assimilation, such as the Calvin–Benson–Bassham cycle. However, the effective impact of Trx f activity on photosynthetic performance and carbon primary metabolism, including under varying CO 2 mole fraction, is not well documented. In this study, we provide a physiological and metabolomic characterization of leaves in transplastomic Trx f over-expressing tobacco ( Nicotiana tabacum L., cv. Petit Havana SR1) grown under either ambient or elevated CO 2 (400 or 800 μmol mol −1 ). Trx f overexpression strongly increased starch synthesis under both ambient and elevated CO 2 but was not accompanied by a stimulation of net photosynthetic CO 2 fixation. Rather, Trx f -overexpressing plants had a lower photorespiration rate due to an increase in internal (mesophyll) conductance for CO 2 (with the consequent increase in CO 2 mole fraction at the carboxylation site, c c ), and a higher decrease (compared with the wild-type) in total photosynthetic electron flux upon acclimation to elevated CO 2 . There were also changes in a number of metabolites, such as enrichment in sugar phosphates and free phosphate, and depletion in alanine, threonine and free sugars. Our results suggest that over-expressing Trx f has an influence on chloroplastic metabolism by simultaneously stimulating the carboxylation-to-oxygenation ratio and starch synthesis, with side effects on amino acid metabolism. The potential mechanisms involved are discussed. [ABSTRACT FROM AUTHOR]

Cold nights impact grapevine flower development and fruit set. Regulation at the female meiosis stepmay be of considerable importance for further understanding on how flower reacts to cold stress. In this study, the impact of chilling temperature (0 °C overnight) on carbon metabolism was investigated in the inflorescencesof two cultivars, Pinot noir (Pinot) and Gewurztraminer (Gewurtz.). Fluctuations in photosynthetic activity and carbohydrate metabolism were monitored by analyzing gas exchanges, simultaneous photosystem I and II activities, andcarbohydrate content. Further, the expression of PEPc , PC , FNR , ISO , OXO , AGPase , amylases and invertase genes, activities of various enzymes, as well as metabolomic analysis were attained. Results showed that the chilling night has different impacts depending on cultivars. Thus, in Gewurtz., net photosynthesis ( P n ) was transiently increased whereas, in Pinot, the P n increase was persistent and concomitant with an inhibition of respiration. However, during the days following the cold night, photosynthetic activity was decreased, and the cyclic electron flow was inhibited in Gewurtz., suggesting lower efficient energy dissipation. Likewise, metabolomic analysis revealed that several metabolites contents (namely alanine, GABA, lysine and succinate)were distinctly modulated in the two cultivars. Taking together, these results reflect a photosynthetic metabolism alteration or internal CO 2 conductance in Gewurtz. explaining partly why Pinot is less susceptible to cold stress. [ABSTRACT FROM AUTHOR]

In the dicot Arabidopsis thaliana , the B3 transcription factors, ABA-INSENSITIVE 3 (ABI3), FUSCA 3 (FUS3) and LEAFY COTYLEDON 2 (LEC2) are key regulators of seed maturation. This raises the question of the role of ABI3/FUS3/LEC2 (AFL) proteins in cereals, where not only the embryo but also the persistent endosperm accumulates reserve substances. Among the five ZmAFL genes identified in the maize genome, ZmAFL2 and ZmAFL3/ZmVp1 closely resemble FUS3 and ABI3 , respectively, in terms of their sequences, domain structure and gene activity profiles. Of the three genes that fall into the LEC2 phylogenetic sub-clade, ZmAFL5 and ZmAFL6 have constitutive gene activity, whereas ZmAFL4 , like LEC2 , has preferential gene activity in pollen and seed, although its seed gene activity is restricted to the endosperm during reserve accumulation. Knock down of ZmAFL4 gene activity perturbs carbon metabolism and reduces starch content in the developing endosperm at 20 DAP. ZmAFL4 and ZmAFL3/ZmVp1 trans -activate a maize oleosin promoter in a heterologous moss system. In conclusion our results suggest, based on gene activity profiles, that the functions of FUS3 and ABI3 could be conserved between dicot and monocot species. In contrast, LEC2 function may have partially diverged in cereals where our findings provide first evidence of the specialization of ZmAFL4 for roles in the endosperm. [ABSTRACT FROM AUTHOR]

Several studies have reported a correlation between pesticides exposure and metabolic disorders. Dichlorodiphenyltrichloroethane (DDT) and permethrin (PMT), two pesticides highly prevalent in the environment, have been associated to dysregulation of liver lipids and glucose metabolisms and non-alcoholic fatty liver disease (NAFLD). However, the effects of DDT/PMT mixtures and mechanisms mediating their action remain unclear. Here, we used multi-omic to investigate the liver damage induced by DDT, PMT and their mixture in rat liver organ-on-chip. Organ-on-chip allow the reproduction of in vivo -like micro-environment. Two concentrations, 15 and 150 μM, were used to expose the hepatocytes for 24 h under perfusion. The transcriptome and metabolome analysis suggested a dose-dependent effect for all conditions, with a profile close to control for pesticides low-doses. The comparison between control and high-doses detected 266/24, 256/24 and 1349/30 genes/metabolites differentially expressed for DDT150, PMT150 and Mix150 (DDT150/PMT150). Transcriptome modulation reflected liver inflammation, steatosis, necrosis, PPAR signaling and fatty acid metabolism. The metabolome analysis highlighted common signature of three treatments including lipid and carbohydrates production, and a decrease in amino acids and krebs cycle intermediates. Our study illustrates the potential of organ-on-chip coupled to multi-omics for toxicological studies and provides new tools for chemical risk assessment. • Rat liver organ-on-chip model was used to study pesticides toxicity. • The model was exposed to DDT, permethrin and their mixtures at 15 and 150 μM. • Transcriptome and metabolome profile showed a dose-dependent effect. • Liver steatosis, inflammation and cell death were common signature for high-doses. • Mixture of DDT and PMT led to additive and increased effects. [ABSTRACT FROM AUTHOR]

• The osmoprotection of Cakile maritima in saline stress is due solely to the accumulation of amino acids. • A Cakile maritima leaves metabolome was managed over time and in three salt conditions (0 mM, 100 mM and 400 mM NaCl). • Photosynthetic and metabolome analysis reveal the facultativ halophily of Cakile maritima in moderate saline condition. The halophyte Cakile maritima is a Brassicacea that has developed numerous mechanisms for managing salt. In the present study, we analyze the metabolic responses of C. maritima to increasing salt exposure in parallel with growth and photosynthetic parameters. At 10 days, 100 mM NaCl treatment has no effect, whereas 400 mM treatment decreases both growth and photosynthetic capacity. Accordingly, the metabolism was weakly impacted at 100 mM NaCl with an increase in only a few amino acids and sugars, whereas 400 mM treated plants shows noticeable changes: an increase in amino acid abundance, sugars decrease and an organic acid depletion. At 20 days, 400 mM treatment leads to more severe effects on growth and photosynthesis, whereas plant growth remains unaffected by the 100 mM NaCl treatment, despite a reduction in photosynthetic capacity. Plants treated with 400 mM NaCl present an amplified metabolic response with additional metabolites reflecting salt stress as GABA, proline and glycine. One noticeable feature of halophily in C. maritima is the increase in sugar content at low stress whereas longer or higher stress lead to a decrease in sugar content. In high salt conditions the stimulation of amino acid biosynthesis is the main strategy for osmoprotection to cope for salt stress. [ABSTRACT FROM AUTHOR]

• Oil palm growth and production is highly dependent on potassium (K) fertilization. • To adjust K fertilization precisely during cultivation, leaf biomarkers that can indicate changes in tree K status before the appearance of symptoms on fruit production and yield, are required. • Here, we investigated the response of oil palm leaf metabolome and proteome to different K fertilization regimes in two crosses (Deli x La Mé , and Deli x Yangambi) grown in the field. • Our result show that one to two years only after the onset of K fertilization treatments, there were changes in N metabolism, photosynthesis and mitochondrial metabolism, with a differential effect in the two crosses. Oil palm growth and production is highly dependent on potassium (K) fertilization. Presently, monitoring K fertilization is difficult since it depends on soil properties, crosses and other nutrients. To adjust K fertilization precisely during cultivation, leaf biomarkers that can indicate changes in tree K status before the appearance of symptoms on fruit production and yield, are required. However, the metabolic response of oil palm leaves to K availability is poorly documented. Here, we investigated the response of oil palm leaf metabolome and proteome to K availability in two crosses (Deli x La Mé , and Deli x Yangambi) grown in the field. Our result show that one to two years only after the onset of K fertilization treatments, there were changes in N metabolism, photosynthesis and mitochondrial metabolism, with a differential effect in the two crosses. In particular, there were changes in sugars, amino and organic acids pointing to modifications in photosynthetic and catabolic (Krebs cycle) capacity and this agreed with the effect seen on enzyme content. Therefore, K availability led to rapid changes in leaf primary metabolism, opening avenues for the utilization of leaf metabolic signature as a marker of K nutrition in oil palm. [ABSTRACT FROM AUTHOR]