A5011270615- Plant nutrient uptake and metabolism
- Legume Nitrogen Fixing Symbiosis
- Plant Molecular Biology Research
- Plant-Microbe Interactions and Immunity
- Agriculture and Rural Development Research
- African Botany and Ecology Studies
- Plant Stress Responses and Tolerance
- Nitrogen and Sulfur Effects on Brassica
- Plant Micronutrient Interactions and Effects
- Soil Carbon and Nitrogen Dynamics
- Potato Plant Research
- Advanced Data Storage Technologies
- Mycorrhizal Fungi and Plant Interactions
- Soybean genetics and cultivation
- ATP Synthase and ATPases Research
- Plant responses to water stress
- Plant Pathogenic Bacteria Studies
- Nosocomial Infections in ICU
- Antibiotic Use and Resistance
- Photosynthetic Processes and Mechanisms
- Crop Yield and Soil Fertility
- Forest Ecology and Biodiversity Studies
- Phytase and its Applications
- Urinary Tract Infections Management
- Rice Cultivation and Yield Improvement
Hôpital Raymond-Poincaré
2020-2023
Assistance Publique – Hôpitaux de Paris
2023
Université de Montpellier
2005-2022
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2022
Institut Agro Montpellier
1992-2022
Centre National de la Recherche Scientifique
1989-2022
Institut des Sciences des Plantes de Montpellier
1996-2019
Laboratoire des Symbioses Tropicales et Méditerranéennes
2003-2014
Centre de Coopération Internationale en Recherche Agronomique pour le Développement
2003-2013
Institut de Recherche pour le Développement
2003-2013
Uptake of nitrate by root cells followed reduction and assimilation in plant tissues is the main route which mineral N converted into organic living organisms. Like photosynthesis, these are life-dependent processes that members animal kingdom unable to perform for themselves. Nitrate other nutrients required optimal growth development frequently exist at relatively low concentrations soil. To thrive on dilute nutrients, plants have developed high-performance uptake systems their cells. cope...
Summary Understanding how biotic interactions can improve plant tolerance to drought is a challenging prospect for agronomy and ecology. Plant growth‐promoting rhizobacteria ( PGPR ) are promising candidates but the phenotypic changes induced by under remain be elucidated. We investigated effects of P hyllobacterium brassicacearum STM 196 strain, isolated from rhizosphere oilseed rape, on two accessions A rabidopsis thaliana with contrasting flowering time. measured multiple...
The activity of ATP sulfurylase extracted from roots intact canola (Brassica napus L. cv Drakkar) increased after withdrawal the S source nutrient solution and declined refeeding SO42- to S-starved plants. rate uptake by was similarly influenced. Identical responses were obtained in -fed when one-half root system starved for S. internal levels glutathione (GSH) starvation whole system, but only GSH concentration +S plants split experiments. phloem exudates decreased upon transfer S-free...
Summary Sulfate uptake and ATP sulfurylase activity in the roots of Arabidopsis thaliana Brassica napus were enhanced by S deprivation reduced following resupply SO 4 2– . Similar responses occurred split‐root experiments where only a portion root system was S‐deprived, suggesting that regulation involves inter‐organ signaling. Phloem‐translocated glutathione (GSH) identified as likely transducing molecule responsible for regulating rate roots. The regulatory role GSH confirmed finding...
Abstract To investigate the regulation of HvNRT2, genes that encode high-affinity NO3 − transporters in barley (Hordeum vulgare) roots, seedlings were treated with 10 mm presence or absence amino acids (aspartate, asparagine, glutamate [Glu], and glutamine [Gln]), NH4 +, and/or inhibitors N assimilation. Although all decreased high-affinity13NO3 influx andHvNRT2 transcript abundance, there was substantial interconversion administered acids, making it impossible to determine which acid(s)...
We have examined the effect of different amino acids on NO⊟3 uptake in 5-d-old soybean (Glycine max L. Merr. cv. Kingsoy) seedlings. Amino were supplied to root either by addition nutrient solution, or immersion tip-cut cotyledons a concentrated solution. was measured its depletion acid-free medium. Provision acid roots resulted an inhibition uptake, mainly with Asp, Glu, Asn, Arg, Ala, βAla, less Ser and Gin, even other acids. Using Arg we shown that accumulated tissues. Immersing solution...
The effects of NaCl on the transport rates cations, NO3-, and reduced N compounds between roots shoot NO3- assimilation rate were examined plants two species differing in their sensitivity to salinity, bean (Phaseolus vulgare L. cv Gabriella) cotton (Gossypium hirsutum Akala). Biomass production after 20 d response 50 100 mM decreased by 48 59% bean, but only 6 14% cotton. comparison flow patterns obtained for control NaCl-fed showed that salinity induced a general decrease all fluxes...
A plant growth-promoting rhizobacterium belonging to the genus Achromobacter was isolated from oilseed-rape (Brassica napus) root. Growth promotion bioassays were performed with oilseed rape seedlings in a growth chamber test tubes containing attapulgite and mineral nutrient solution, NO 3 - as N source. The presence of this strain increased shoot root dry weight by 22-33% 6-21%, respectively. Inoculation young bacteria induced 100% improvement uptake whole system. Observations on seminal 20...
The Arabidopsis thaliana AtNRT2.1 gene, which encodes a NO(3)(-) transporter involved in high-affinity uptake by the roots, is molecular target of several mechanisms responsible for regulation root acquisition N status plant. All levels expression (promoter activity, transcript level, protein accumulation, transport activity) are coordinately up-regulated presence NO(3)(-), and repressed downstream metabolites. Transgenic plants expressing GUS reporter gene under control upstream sequences...
Summary The Phyllobacterium brassicacearum STM 196 strain stimulates Arabidopsis thaliana growth and antagonizes high nitrate inhibition of lateral root development. A previous study identified two 196‐responsive genes, NRT 2.5 2.6 (Mantelin et al ., 2006, Planta 223: 591–603). We investigated the role in plant response to using single double mutants. mutants were also crossed with an nrt2.1 mutant, lacking major transporter, distinguish effects from potential indirect pools. nrt2.5 nrt2.6...
Hst1At (accession number AB018695) was identified from the Arabidopsis thaliana sequencing project on BAC T3F12, and corresponding cDNA isolated by reverse transcription‐PCR. Southern blot analysis reveals a single copy of this gene. The encodes root specific sulfate transporter 649 amino acids. Heterologous expression hst1At in transport deficient yeast mutant shows that gene high‐affinity system (∼2 μM). transcript relative abundance increases roots response to deprivation, which...
6(5)carboxyfluorescein (6(5)CF), a polar fluorescein with an apparent pK of 6.3, was introduced, as pH 6.3 solution, into the apoplast lamina or petioles mature soybean leaves. Freehand sections were prepared at various times and immediately observed fluorescence microscope. 6(5)CF‐associated appeared in all sink organs, from shoot apex to roots. It strictly confined phloem regions, even after 4 days. Its transport young leaves ceased approximately time they underwent sink‐to‐source...
Induced systemic resistance (ISR) is a process elicited by telluric microbes, referred to as plant growth-promoting rhizobacteria (PGPR), that protect the host against pathogen attacks. ISR has been defined from studies using Pseudomonas strains biocontrol agent. Here, we show for first time photosynthetic Bradyrhizobium sp. strain, ORS278, also exhibits ability promote in Arabidopsis thaliana, indicating effect may be widespread ability. To investigate molecular bases of this response,...
Root hairs are involved in water and nutrient uptake, thereby plant autotrophy. In legumes, they also play a crucial role establishment of rhizobial symbiosis. To obtain holistic view Medicago truncatula genes expressed root their regulation during the first hours engagement symbiotic interaction, high throughput RNA sequencing on isolated from roots challenged or not with lipochitooligosaccharides Nod factors (NF) for 4 h 20 was carried out. This provided repertoire displaying expression...
ABSTRACT The effect of ectomycorrhizal association Pinus pinaster with Hebeloma cylindrosporum was investigated in relation to the nitrogen source supplied as mineral (NH 4 + or NO 3 − ) organic N ( L ‐glutamate) and at 5 mol m . Plants were grown for 14 16 weeks N, respectively, samples collected during last 6 culture. Total fungal biomass estimated using glucosamine amount its viability assessed ergosterol ratio. Non‐mycorrhizal plants grew better NH than very slowly when ‐glutamate....
Soybeans (Glycine max L. Merr., cv Kingsoy) were grown on media containing NO(3) (-) or urea. The enrichments of shoots in K(+), (-), and total reduced N (N(r)), relative to that Ca(2+), compared the ratios K(+)/Ca(2+),NO(3) (-)/Ca(2+), N(r)/Ca(2+) xylem saps, estimate cycling N(r). net production carboxylates (R(-)) was estimated from difference between sums main cations inorganic anions. for theoretical R(-) associated with assimilation these organs, attributed export roots. exchange rates...
In soybean (Glycine max L. Merr. cv Kingsoy), NO3− assimilation in leaves resulted production and transport of malate to roots (B Touraine, N Grignon, C Grignon [1988] Plant Physiol 88: 605-612). This paper examines the significance this phenomenon for control uptake by roots. The net rate plants was stimulated addition K-malate external solution. It decreased when phloem translocation interrupted hypocotyl girdling, partially restored medium, whereas glucose ineffective. Introduction into...
Using their 1 amino cyclopropane-1-carboxylic acid (ACC) deaminase activity, many rhizobacteria can divert ACC from the ethylene biosynthesis pathway in plant roots. To investigate role of this microbial activity responses to growth-promoting (PGPR), we analyzed effects acdS knock-out and wild-type PGPR strains on two phenotypic inoculation –root hair elongation root system architecture– Arabidopsis thaliana. Our work shows that rhizobacterial AcdS has a negative effect elongation, as...