A5081396806- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Photoreceptor and optogenetics research
- Mitochondrial Function and Pathology
- Plant nutrient uptake and metabolism
- Microbial Metabolites in Food Biotechnology
- Spectroscopy and Quantum Chemical Studies
- Light effects on plants
- Polysaccharides and Plant Cell Walls
- Plant Molecular Biology Research
- Marine and coastal ecosystems
- ATP Synthase and ATPases Research
- Plant Reproductive Biology
- Electrohydrodynamics and Fluid Dynamics
- Retinal Development and Disorders
- Plant Stress Responses and Tolerance
- Agriculture Sustainability and Environmental Impact
- Hemoglobin structure and function
- Electrocatalysts for Energy Conversion
- Genomics and Phylogenetic Studies
- Microbial Fuel Cells and Bioremediation
- Porphyrin Metabolism and Disorders
- Advanced Fluorescence Microscopy Techniques
- Protist diversity and phylogeny
- Plant Water Relations and Carbon Dynamics
Institut de Biosciences et Biotechnologies
2015-2024
CEA Cadarache
2013-2024
Aix-Marseille Université
2013-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014-2024
Centre National de la Recherche Scientifique
2014-2024
Institut de Biologie Physico-Chimique
2008-2023
Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues
2008-2023
Sorbonne Université
2008-2023
Institute of Environmental Biology and Biotechnology
2013-2022
Institut de Biosciences et biotechnologies d'Aix-Marseille
2016
Abstract Physiological and genetic studies with the ramosus (rms) mutants in garden pea (Pisum sativum) more axillary shoots (max) Arabidopsis (Arabidopsis thaliana) have shown that shoot branching is regulated by a network of long-distance signals. Orthologous genes RMS1 MAX4 control synthesis novel graft-transmissible signal may be carotenoid derivative acts as inhibitor. In this study, we demonstrate further conservation system showing MAX2 MAX3 are orthologous to RMS4 RMS5, respectively....
By homology with the unique plastid terminal oxidase (PTOX) found in plants, two genes encoding oxidases have been Chlamydomonas genome, PTOX1 and PTOX2 . Here we report identification of a knockout mutant Its molecular functional characterization demonstrates that it encodes most predominantly involved chlororespiration this algal species. In mutant, plastoquinone pool is constitutively reduced under dark-aerobic conditions, resulting mobile light-harvesting complexes being mainly, but...
Abstract We identify and functionally characterize MRL1, a conserved nuclear-encoded regulator of the large subunit ribulose-1,5-bisphosphate carboxylase/oxygenase. The nonphotosynthetic mrl1 mutant Chlamydomonas reinhardtii lacks carboxylase/oxygenase, resulting block in electron transfer is partially compensated by redirecting electrons toward molecular oxygen via Mehler reaction. This allows continued flow constitutive nonphotochemical quenching, enhancing cell survival during...
Abstract The Chlamydomonas reinhardtii proton gradient regulation5 (Crpgr5) mutant shows phenotypic and functional traits similar to mutants in the Arabidopsis (Arabidopsis thaliana) ortholog, Atpgr5, providing strong evidence for conservation of PGR5-mediated cyclic electron flow (CEF). Comparing Crpgr5 with wild type, we discriminate two pathways CEF determine their maximum rates. PGR5/proton regulation-like1 (PGRL1) ferredoxin (Fd) pathway, involved recycling excess reductant increase ATP...
Abstract During oxygenic photosynthesis, metabolic reactions of CO2 fixation require more ATP than is supplied by the linear electron flow operating from photosystem II to I (PSI). Different mechanisms, such as cyclic (CEF) around PSI, have been proposed participate in reequilibrating ATP/NADPH balance. To determine contribution CEF microalgal biomass productivity, here, we studied photosynthesis and growth performances a knockout Chlamydomonas reinhardtii mutant (pgrl1) deficient PROTON...
Summary Photosynthetic organisms have evolved numerous photoprotective mechanisms and alternative electron sinks/pathways to fine‐tune the photosynthetic apparatus under dynamic environmental conditions, such as varying carbon supply or fluctuations in light intensity. In cyanobacteria flavodiiron proteins ( FDP s) protect from photodamage fluctuating FL ). Arabidopsis thaliana , which does not possess s, PGR 5‐related pathway enables photoprotection. The direct comparison of pgr5 pgrl1 flv...
Continuous hydrogen photo-production under sulfur deprivation was studied in the Chlamydomonas reinhardtii pgr5 pgrl1 double mutant and respective single mutants. Under medium light conditions, exhibited highest performance produced about eight times more than wild type, making one of most efficient producer reported so far. The showed an increased burst at beginning high but this case overall amount by as well diminished due to photo-inhibition degradation PSI. In contrast, effective...
Significance Our results suggest that particular ferredoxins in photosynthetic organisms are tailored to serve as electron carriers sustain day-time and night-time metabolism the chloroplast-localized ferredoxin-5 (FDX5) appears function desaturation of fatty acids required for maintaining correct ratio dominant lipids thylakoid membranes integration chloroplast mitochondrial metabolism, which is absolutely growth dark. The most important messages from this work redox components associated...
The cytochrome (cyt)
Chlamydomonas reinhardtii, a unicellular green alga, has been exploited as reference organism for identifying proteins and activities associated with the photosynthetic apparatus functioning of chloroplasts. Recently, full genome sequence was generated set gene models, representing all genes on genome, developed. Using these models developed genomes other organisms, phylogenomic, comparative analysis performed to identify encoded which were likely involved in chloroplast functions (or...
Abstract In the last common enzymatic step of tetrapyrrole biosynthesis, prior to branching point leading biosynthesis heme and chlorophyll, protoporphyrinogen IX (Protogen) is oxidised protoporphyrin (Proto) by oxidase (PPX). The absence thylakoid-localised plastid terminal 2 (PTOX2) cytochrome b 6 f complex in ptox2 petB mutant, results almost complete reduction plastoquinone pool (PQ pool) light. Here we show that lack PQ impairs PPX function, accumulation subsequently uncontrolled...
Protein phosphorylation plays important roles in short-term regulation of photosynthetic electron transfer, and during state transitions, the kinase STATE TRANSITION7 (STT7) Chlamydomonas reinhardtii phosphorylates components light-harvesting antenna complex II (LHCII). This reversible governs dynamic allocation a part LHCII to PSI or PSII, depending on light conditions metabolic demands, but counteracting phosphatase(s) remain unknown C. reinhardtii. Here we analyzed transitions mutants two...
In plants and algae, chloroplast gene expression is controlled by nucleus-encoded proteins that bind to mRNAs in a specific manner, stabilizing or promoting their splicing, editing, translation. Here, we present the characterization of two mRNA stabilization factors green alga Chlamydomonas reinhardtii, which both belong OctotricoPeptide Repeat (OPR) family. MCG1 necessary stabilize petG mRNA, encoding small subunit cytochrome b6 f complex, while MBI1 stabilizes psbI coding for photosystem...
In land plants and cyanobacteria, co-translational association of chlorophyll (Chl) to the nascent D1 polypeptide, a reaction center protein photosystem II (PSII), requires Chl binding complex consisting short-chain dehydrogenase (high fluorescence 244 [HCF244]/uncharacterized 39 [Ycf39]) one-helix proteins (OHP1 OHP2 in chloroplasts) light-harvesting antenna superfamily. Here, we show that an ohp2 mutant green alga Chlamydomonas (Chlamydomonas reinhardtii) fails accumulate core PSII...
The nucleo-cytoplasmic compartment exerts anterograde control on chloroplast gene expression through numerous proteins that intervene at posttranscriptional steps. Here, we show the maturation of psaC mutant (mac1) Chlamydomonas reinhardtii is defective in photosystem I and fails to accumulate mRNA. MAC1 locus encodes a member Half-A-Tetratricopeptide (HAT) family super-helical repeat proteins, some which are involved RNA transactions. Mac1 protein localizes soluble fraction. acts 5'...