A5081738037- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Plant Stress Responses and Tolerance
- Marine and coastal ecosystems
- Plant Micronutrient Interactions and Effects
- Aluminum toxicity and tolerance in plants and animals
- Lipid metabolism and biosynthesis
- Photoreceptor and optogenetics research
- Metalloenzymes and iron-sulfur proteins
- Trace Elements in Health
- Light effects on plants
- Plant-Microbe Interactions and Immunity
- Plant Parasitism and Resistance
- Genomics and Phylogenetic Studies
- Enzyme Catalysis and Immobilization
- Retinal Development and Disorders
- Mitochondrial Function and Pathology
- Microbial Metabolic Engineering and Bioproduction
- Legume Nitrogen Fixing Symbiosis
- Nitrogen and Sulfur Effects on Brassica
- Plant nutrient uptake and metabolism
- Advanced Glycation End Products research
Centre National de la Recherche Scientifique
2004-2024
Institut de Biosciences et Biotechnologies
2016-2024
CEA Cadarache
2006-2024
Aix-Marseille Université
2011-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2011-2024
Institute of Environmental Biology and Biotechnology
2014-2018
Institut de Biosciences et biotechnologies d'Aix-Marseille
2016
Ecologie Microbienne Lyon
2011
Université de Bourgogne
2009
AtHMA4 is an Arabidopsis thaliana P 1B ‐ATPase which transports Zn and Cd. Here, we demonstrate that localized at the plasma membrane expressed in tissues surrounding root vascular vessels. The ectopic overexpression of improved growth presence toxic concentrations Zn, Cd Co. A null mutant exhibited a lower translocation from roots to shoot. In contrast, overexpressing lines displayed increase zinc cadmium shoot content. Altogether, these results strongly indicate plays role metal loading xylem.
Abstract Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, role for NO the regulation of iron homeostasis and plant response to toxic metals has been proposed. Here, we investigated synthesis plants exposed cadmium (Cd2+), nonessential metal. We demonstrate that Cd2+ induces roots leaves Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive synthase inhibitors, does not involve nitrate reductase AtNOA1 but requires IRT1, encoding...
Microalgae are regarded as promising organisms to develop innovative concepts based on their photosynthetic capacity that offers more sustainable production than heterotrophic hosts. However, realize potential green cell factories, a major challenge is make microalgae easier engineer. A approach for rapid and predictable genetic manipulation use standardized synthetic biology tools workflows. To this end we have developed Modular Cloning toolkit the microalga Chlamydomonas reinhardtii. It...
Although ions play important roles in the cell and chloroplast metabolism, little is known about ion transport across envelope. Using a proteomic approach specifically targeted to Arabidopsis envelope, we have identified HMA1, which belongs metal-transporting P1B-type ATPases family. HMA1 mainly expressed green tissues, validated its envelope localization. Yeast expression experiments demonstrated that involved copper homeostasis deletion of N-terminal His-domain partially affects metal...
The Arabidopsis thaliana AtHMA3 protein belongs to the P 1B ‐adenosine triphosphatase (ATPase) transporter family, involved in heavy metal transport. Functional expression of phenotypically complements Cd/Pb‐hypersensitive yeast strain Δ ycf1 , but not Zn‐hypersensitive mutant zrc1 . AtHMA3‐complemented cells accumulate same amount cadmium as YCF1‐complemented or wild‐type cells, suggesting that carries out an intracellular sequestration Cd. A altered P‐ATPase phosphorylation domain did...
Hydrogen photoproduction by eukaryotic microalgae results from a connection between the photosynthetic electron transport chain and plastidial hydrogenase. Algal H2 production is transitory phenomenon under most natural conditions, often viewed as safety valve protecting overreduction. From colony screening of an insertion mutant library unicellular green alga Chlamydomonas reinhardtii based on analysis dark-light chlorophyll fluorescence transients, we isolated impaired in cyclic flow...
During oxygenic photosynthesis, the reducing power generated by light energy conversion is mainly used to reduce carbon dioxide. In bacteria and archae, flavodiiron (Flv) proteins catalyze O2 or NO reduction, thus protecting cells against oxidative nitrosative stress. These are found in cyanobacteria, mosses, microalgae, but have been lost angiosperms. Here, we chlorophyll fluorescence oxygen exchange measurement using [18O]-labeled a membrane inlet mass spectrometer characterize...
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...
Abstract Photosynthetic organisms must respond to excess light in order avoid photo-oxidative stress. In plants and green algae the fastest response high is non-photochemical quenching (NPQ), a process that allows safe dissipation of energy as heat. This phenomenon triggered by low luminal pH generated photosynthetic electron transport. vascular main sensor PsbS protein, while alga Chlamydomonas reinhardtii LhcSR proteins appear be exclusively responsible for this role. Interestingly, also...
Enriching algal biomass in energy density is an important goal biotechnology. Nitrogen (N) starvation considered the most potent trigger of oil accumulation microalgae and has been thoroughly investigated. However, N causes slow down eventually arrest growth. In this study, we show that exposing a Chlamydomonas reinhardtii culture to saturating light (SL) under nonlimiting CO2 concentration turbidostatic photobioreactors induces sustained lipid droplets (LDs) without compromising growth,...
The Arabidopsis thaliana AtHMA4 is a P1B-type ATPase that clusters with the Zn/Cd/Pb/Co subgroup. It has been previously shown, by heterologous expression and study of knockout or overexpressing lines in [1-3], implicated zinc homeostasis cadmium tolerance. Here, we report yeast Saccharomyces cerevisiae. resulted an increased tolerance to Zn, Cd Pb phenotypic complementation hypersensitive mutants. In contrast, sensitivity towards Co was observed. An AtHMA4::GFP fusion protein observed...
The cytochrome (cyt)
Because of their high biomass productivity and ability to accumulate levels energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production biofuel. Accumulation takes place when face adverse situations nutrient shortage, conditions which also provoke stop in cell division, down-regulation photosynthesis. Despite growing interest microalgal biofuels, little is known about molecular mechanisms controlling carbon formation. In order discover...
Some microalgae, such as Chlamydomonas reinhardtii, harbor a highly flexible photosynthetic apparatus capable of using different electron acceptors, including carbon dioxide (CO2), protons, or oxygen (O2), allowing survival in diverse habitats. During anaerobic induction photosynthesis, molecular O2 is produced at photosystem II, while the I acceptor side, reduction protons into hydrogen (H2) by plastidial [FeFe]-hydrogenases primes CO2 fixation. Although interaction between H2 production...
Biological conversion of solar energy into hydrogen is naturally realized by some microalgae species due to a coupling between the photosynthetic electron transport chain and plastidial hydrogenase. While promising for production clean sustainable hydrogen, this process requires improvement be economically viable. Two pathways, called direct indirect photoproduction, lead sustained in sulfur-deprived Chlamydomonas reinhardtii cultures. The pathway allows an efficient time-based separation O2...
Abstract Use of microbes to produce liquid transportation fuels is not yet economically viable. A key point reduce production costs the design a cell factory that combines continuous drop-in fuel molecules with ability recover products from culture at low cost. Medium-chain hydrocarbons seem ideal targets because they can be produced abundant fatty acids and, due their volatility, easily collected in gas phase. However, pathways used require two steps, efficient enzymes and/or complex...
Changes in the expression levels of P<sub>1B2</sub>-ATPases <italic>Arabidopsis</italic> impacts Zn and Cd contents shoots seeds.
Microalgae accumulate high levels of oil under stress, but the underlying biosynthetic pathways are not fully understood. We sought to identify key regulators lipid metabolism stress conditions. found that Chlamydomonas reinhardtii gene encoding MYB-type transcription factor MYB1 is highly induced Two myb1 mutants accumulated less total fatty acids and storage lipids than their parental strain upon nitrogen (N) depletion. Transcriptome analysis revealed genes involved in enriched wild-type...
Abstract Nitrogen (N) scarcity frequently constrains global biomass productivity. N deficiency halts cell division, downregulates photosynthetic electron transfer (PET), and enhances carbon storage. However, the molecular mechanism downregulating photosynthesis during its relationship with storage are not fully understood. Proton gradient regulator-like 1 (PGRL1) controlling cyclic flow (CEF) flavodiiron proteins (FLV) involved in pseudo-CEF (PCEF) major players acclimation of...
Site-directed mutagenesis of chloroplast genes was developed three decades ago and has greatly advanced the field photosynthesis research. Here, we describe a new approach for generating random gene mutants that combines error-prone polymerase chain reaction interest with complementation knockout Chlamydomonas reinhardtii mutant. As proof concept, targeted 300-bp sequence petD encodes subunit IV thylakoid membrane-bound cytochrome b 6 f complex. By sequencing transformants, revealed 149...
Abstract An arsenal of effector proteins from plant pathogenic Phytophthora species manipulates their host inside the cells. parasitica produces AVH195 during an initial, biotrophic phase infection. The protein transiently impairs immune-associated hypersensitive cell death in Nicotiana . ATG8 Interaction Motifs indicate that targets autophagic core machinery. We selected a photosynthetic microalga with single copy gene as alternative model to dissect AVH195-induced perturbation. slows down...
Abstract Due to low availability of CO 2 in aquatic environment, microalgae have evolved a concentrating mechanism (CCM). It has long been thought that operation CCM would suppress photorespiration by increasing the concentration at Rubisco active site, but experimental evidence is scarce. To better explore function algae, we first characterized Chlamydomonas reinhardtii mutant defected low-CO inducible 20 (LCI20) and show LCI20 chloroplast-envelope glutamate/malate transporter playing role...