Search results for "Pyoverdine"
showing 10 items of 20 documents
Metabolic fate of a bacterial siderophore in Arabidopsis thaliana and Pisum sativum in relationship with iron status in plants
2018
Despite its abundance, iron is weakly bioavailable for organisms due to its poor solubility in soils under aerobic conditions. Therefore, plants and other organisms have evolved mechanisms to efficiently assimilate iron from the soil. Non-grass plants use a strategy (strategy I) based on soil acidification, reduction of the Fe3+ in Fe2+ which incorporated in the roots by iron transporters. We previously showed (Shirley et al., 2011; Vansuyt et al., 2007) that iron nutrition and growth of a strategy I plant could be promoted by the ferric-complex of the pyoverdine (Fe-pvd), a siderophore produced by microorganisms. If pyoverdine was further localized in planta using different immunological t…
Reciprocal interactions between plants and fluorescent pseudomonads in relation with iron in the rhizosphere
2008
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Influence of pea genotype on root associated fluorescent pseudomonads, impact on plant iron nutrition
2019
International audience; Pea has a high potential in agroecology because of its ability to fix atmospheric nitrogen and for Humannutrition due to the high amino-acids content of its seeds. However, pea can suffer from a susceptibility toiron deficiency in calcareous soils as expressed by chlorosis symptoms. Previous studies have shown thatsiderophores of model strains of fluorescent pseudomonads (fp), pyoverdines, promote iron nutrition ofarabidopsis and tobacco. We hypothesized that susceptibility to iron deficiency of pea is at least partly dueto its ability to select fluorescent pseudomonad that promote differentially plant nutrition thanks to theirsiderophores.To identify siderophores po…
Reciprocal interactions between plants and fluorescent pseudomonads in relation with iron in the rhizosphere
2007
International audience; Iron is an essential element for plants and microbes. However, in most cultivated soils, the concentration of iron available for these living organisms is very low since its solubility is controlled by stable hydroxides, oxyhydroxides and oxides. The high demand for iron by plants and microorganisms in the rhizosphere together with its low availability in soils leads to a strong competition for this nutrient among living organisms. To face this competition, plants and microorganisms have developed active strategies of iron uptake. In non graminaceous plants (strategy I), iron uptake relies on acidification and reduction of Fe+++ in Fe++ which incorporated in the root…
Establishment of tools for investigating pyoverdine impact on iron homeostasis and plant defense responses
2013
Iron, the fourth major element in the Earth crust, is essential for growth and development of living organisms. However, due to its low solubility in the soil, it is weakly available for plants and micro-organisms. To efficiently assimilate iron, living organisms have evolved specific strategies. In plants such as Arabidopsis thaliana three trans-membrane proteins are involved in iron assimilation while in bacteria such as Pseudomonas fluorescens iron is taken up from the soil thanks to molecules displaying high affinity for iron called siderophores. It has been recently shown that pyoverdine, the major siderophore of the beneficial bacterium Pseudomonas fluorescens, is assimilated by A. th…
Interactions between Pisum sativum & pseudomonads, consequences on plant iron nutrition and growth and immunity
2019
Pea has a high potential in agroecology, however, it may suffer from a susceptibility to iron deficiency in calcareous soils. This susceptibility varies depending on cultivars. Pseudomonad siderophores, pyoverdines (pvd), were shown to promote iron nutrition in Arabidopsis and tobacco. The hypothesis was therefore raised that variation in iron susceptibility between pea cultivars could be related to differences in their ability to recruit fluorescent pseudomonads (fp) contributing to siderophore-mediated iron nutrition. Our aims were to compare i) the impact of a susceptible (S) and a tolerant (T) cultivar of pea on fp biodiversity with a focus on their pvd, and in return ii) the impact of …
Analysis of the cross‐regulation between immunity, growth and iron homeostasis in plants
2019
The existence of a tightly regulated balance between growth and immunity in plants has recently emerged. In this study, we challenged this concept thanks to the biological model pyoverdine-Arabidopsis thaliana. Pyoverdine is a siderophore produced by the plant growth promoting rhizobacteria Pseudomonas fluorescens C7R12. Under iron deficiency, P. fluorescens excretes the iron free form of pyoverdine (apo‐pyo) in the soil. Once chelated with iron (ferri‐pyo), the complex is internalized by the bacteria. We demonstrated that Arabidopsis thaliana plants treated by apo‐pyo in a medium containing or not iron internalize pyoverdine. Interestingly, apo‐pyo-treated plants did not show a typical gro…
Analysis of the role of nitric oxide (NO) in the cross‐regulation between immunity, growth and iron homeostasis in plants
2019
Studies performed in our Agroecology Department show that the immune response of plants is linked to their iron nutrition and is modulated by pyoverdine, a siderophore produced by the plant beneficial rhizobacteria Pseudomonas fluorescens C7R12. Accordingly, Arabidopsis thaliana plantlets exposed to iron deficiency and treated with pyoverdine in its iron non‐chelated structure (apo‐pyo) show an enhanced growth but a decreased immune response capacity. We hypothesize that nitric oxide (NO), a universal signaling molecule, is a key component of the regulation of the immune response in plants exposed to apo‐pyo and to the C7R12 strain. We checked by fluorescence microscopy that NO is actually …
Variation in the TonB-dependent outer-membrane proteins in plant-associated strains of Pseudomonas fluorescens
2011
International audience; Genomic sequences of ten strains of plant-associated Pseudomonas spp. were surveyed for the presence of TonB-dependent outer-membrane proteins (TBDPs), which function in the uptake of substrates from the environment by many Gram-negative bacteria. The ten strains represent P. fluorescens, P. chlororaphis, and P. synxantha isolated from the phyllosphere, rhizosphere or soil. 14 to 45 TBDPs were identified in each strain, and phylogenetic analysis of the TBDPs identified five that are conserved across all ten genomes. Comparisons to proteins with known functions allowed the assignment of putative roles in uptake of heme, vitamin B12, copper, and the siderophore ferrich…
Identification et analyse du rôle de protéines S‐nitrosylées lors de la modulation de la réponse immunitaire d’Arabidopsis thaliana par l’apo-pyoverd…
2019
Des travaux de l’UMR Agroécologie montrent que la réponse immunitaire des plantes est corrélée à leur nutrition en fer et est modulable par la pyoverdine, un sidérophore produit par la souche bactérienne bénéfique Pseudomonas fluorescens C7R12. Le traitement d’Arabidopsis thaliana exposée à une carence en fer par la pyoverdine dépourvue de fer (apo-pyo) restaure en effet la croissance de la plante aux dépens de son immunité. Nous avons émis l’hypothèse que le monoxyde d’azote (NO), une molécule signalétique ubiquitaire, est un acteur de la modulation de la réponse immunitaire des plantes exposées à l’apo-pyo et à sa souche productrice. Afin d’étayer cette hypothèse, trois axes seront dévelo…