A5073564980- Plant Stress Responses and Tolerance
- Plant Micronutrient Interactions and Effects
- Photosynthetic Processes and Mechanisms
- Plant Molecular Biology Research
- Metalloenzymes and iron-sulfur proteins
- Plant nutrient uptake and metabolism
- Ion channel regulation and function
- Plant Reproductive Biology
- Plant and Biological Electrophysiology Studies
- Aluminum toxicity and tolerance in plants and animals
- Plant responses to water stress
- Electrocatalysts for Energy Conversion
- Redox biology and oxidative stress
- Enzyme Structure and Function
- Iron oxide chemistry and applications
- Ion Channels and Receptors
- Agriculture and Rural Development Research
- Metal-Catalyzed Oxygenation Mechanisms
- Nitrogen and Sulfur Effects on Brassica
- Plant chemical constituents analysis
- Forest Ecology and Biodiversity Studies
- Plant Gene Expression Analysis
- Mycorrhizal Fungi and Plant Interactions
- Polysaccharides and Plant Cell Walls
- Molecular Junctions and Nanostructures
Centre National de la Recherche Scientifique
2002-2022
Institut Agro Montpellier
2013-2022
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2022
Université de Montpellier
2001-2022
Institut des Sciences des Plantes de Montpellier
2012-2022
Institut National de la Recherche Agronomique
2015
Université de Bourgogne
2009
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009
Laboratoire Génome et Développement des Plantes
2002
Département Biologie et Amélioration des Plantes
2002
Plants are the principal source of iron in most diets, yet availability often limits plant growth. In response to deficiency, Arabidopsis roots induce expression divalent cation transporter IRT1. Here, we present genetic evidence that IRT1 is essential for uptake from soil. An knockout mutant chlorotic and has a severe growth defect soil, leading death. This rescued by exogenous application iron. The plants do not take up fail accumulate other cations low-iron conditions. IRT1–green...
A membrane polypeptide involved in K+ transport a higher plant was cloned by complementation of yeast mutant defective uptake with complementary DNA library from Arabidopsis thaliana. 2.65-kilobase conferred ability to grow on media concentration the micromolar range and absorb (or 86Rb+) at rates similar those wild-type yeast. The predicted amino acid sequence (838 acids) has three domains: channel-forming region homologous animal channels, cyclic nucleotide-binding site, an ankyrin-like region.
Microscopic pores present in the epidermis of plant aerial organs, called stomata, allow gas exchanges between inner photosynthetic tissue and atmosphere. Regulation stomatal aperture, preventing excess transpirational vapor loss, relies on turgor changes two highly differentiated epidermal cells surrounding pore, guard cells. Increased cell due to increased solute accumulation results opening, whereas decreased closing. Here we provide direct evidence, based reverse genetics approaches,...
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...
Summary Studies of Iron (Fe) uptake mechanisms by plant roots have focussed on Fe( III )‐siderophores or II ) transport systems. deficency also enhances root secretion flavins and phenolics. However, the nature these compounds, their outside role in Fe nutrition are largely unknown. We used HPLC / ESI ‐ MS ( TOF (ion trap) to characterize fluorescent phenolic‐type compounds accumulated exported culture medium Arabidopsis plants response deficiency. Wild‐type mutant altered either...
Iron is one of the most important micronutrients in plants as it involved many cellular functions (e.g., photosynthesis and respiration). Any defect iron availability will affect plant growth development well crop yield product quality. Thus, homeostasis must be tightly controlled order to ensure optimal absorption this mineral element. Understanding mechanisms governing has been focus several studies during past 10 years. These have greatly improved our understanding involved, revealing a...
Iron (Fe) is an essential micronutrient for plant growth and development. Any defects in the maintenance of Fe homeostasis will alter productivity quality their derived products. In Arabidopsis (Arabidopsis thaliana), transcription factor ILR3 plays a central role controlling homeostasis. this study, we identified bHLH121 as ILR3-interacting factor. Interaction studies showed that also interacts with three closest homologs (i.e., basic-helix-loop-helix 34 [bHLH34], bHLH104, bHLH115). bhlh121...
Stomatal opening, which controls gas exchanges between plants and the atmosphere, results from an increase in turgor of two guard cells that surround pore stoma. KAT1 was only inward K+ channel shown to be expressed Arabidopsis cells, where it proposed mediate a influx enables stomatal opening. We report another K+channel, KAT2, is cells. More than KAT1, KAT2 displays functional features resembling those native channels Coexpression inXenopus oocytes two-hybrid experiments indicated can form...
Sexual reproduction in plants requires elongation of the pollen tube through transmitting tissues toward ovary. Tube growth rate is a major determinant competitive ability. We report that K + channel Shaker family Arabidopsis , SPIK, plays an important role development. SPIK was found to be specifically expressed pollen. When heterologously COS cells, its product formed hyperpolarization-activated channels. Disruption (T-DNA insertion) coding sequence strongly affected inwardly rectifying...
RNA gel blot and reverse transcription–polymerase chain reaction experiments were used to identify a single K+ channel gene in Arabidopsis as expressed throughout the plant. Use of β-glucuronidase reporter revealed expression this gene, AKT2/AKT3, both source sink phloem tissues. The AKT2/AKT3 corresponds two previously identified cDNAs, AKT2 (reconstructed at its 5′ end) AKT3, open reading frame latter being shorter end than that former. Rapid amplification cDNA ends with polymerase...
Summary Iron (Fe) homeostasis is crucial for all living organisms. In mammals, an integrated posttranscriptional mechanism couples the regulation of both Fe deficiency and excess responses. Whether in plants control involving common players regulates responses to still be determined. this study, molecular, genetic biochemical approaches were used investigate transcriptional excess. A activator shortage Arabidopsis, called bHLH105/ILR3, was found also negatively regulate expression ferritin...
Summary Iron (Fe) is a major micronutrient and required for plant growth development. Nongrass species have evolved reduction‐based strategy to solubilize take up Fe. The secretion of Fe‐mobilizing coumarins (e.g. fraxetin, esculetin sideretin) by roots plays an important role in this process. Although the biochemical mechanisms leading their biosynthesis been well described, very little known about cellular subcellular localization or mobility within tissues. Spectral imaging was used...
Summary The open reading frame from the Arabidopsis thaliana KAT1 cDNA was cloned in a transcription plasmid between 3′ and 5′ untranslated regions of β‐globin Xenopus oocyte. polyadenylated transcripts resulting vitro gave rise to high levels expression channel when injected oocytes. Upon hyperpolarization, slow activating current could be recorded, inwardly‐ or outwardly‐directed, depending on K + external concentration. Predictions voltage‐gated theory were shown fit data well. equivalent...
Glutaredoxins (GRXs) catalyze the reduction of protein disulfide bonds using glutathione as a reductant. Certain GRXs are able to transfer iron-sulfur clusters other proteins. To investigate function Arabidopsis (Arabidopsis thaliana) GRXS17, we applied strategy combining biochemical, genetic, and physiological approaches. GRXS17 was localized in nucleus cytosol, its expression elevated shoot meristems reproductive tissues. Recombinant bound Fe2S2 clusters, property likely contributing...
Plants need to cope with strong variations of nitrogen availability in the soil. Although many molecular players are being discovered concerning how plants perceive NO3- provision, it is less clear recognize a lack nitrogen. Following removal, activate their starvation response (NSR), which characterized by activation very high-affinity nitrate transport systems (NRT2.4 and NRT2.5) other sentinel genes involved N remobilization such as GDH3. Using combination functional genomics via...
Abstract Stomata optimize land plants’ photosynthetic requirements and limit water vapor loss. So far, all of the molecular electrical components identified as regulating stomatal aperture are produced, operate, directly within guard cells. However, a completely autonomous function cells is inconsistent with anatomical biophysical observations hinting at mechanical contributions epidermal origins. Here, potassium (K+) assays, membrane potential measurements, microindentation, plasmolysis...
SKOR, an Arabidopsis depolarisation‐activated K + ‐selective channel, was expressed in Xenopus oocytes, and external internal pH effects were analysed. Internal manipulated by injections of alkaline or acidic solutions acid load from acetate‐containing medium. An decrease 7.4 to 7.2 induced a strong (ca. 80%) voltage‐independent the macroscopic SKOR current, gating parameters single channel conductance remained unchanged. acidification 6.4 had similar effects. It is proposed that changes...
Abstract Iron–sulfur (Fe-S) proteins have critical functions in plastids, notably participating photosynthetic electron transfer, sulfur and nitrogen assimilation, chlorophyll metabolism, vitamin or amino acid biosynthesis. Their maturation relies on the so-called SUF (sulfur mobilization) assembly machinery. Fe-S clusters are synthesized de novo a scaffold protein complex then delivered to client via several transfer proteins. However, pathways of most their specificities for mostly...