Interaction between Medicago truncatula and Pseudomonas fluorescens: evaluation of costs and benefits across an elevated atmospheric CO2.

10 pagesInternational audienceSoil microorganisms play a key role in both plants nutrition and health. Their relation with plant varies from mutualism to parasitism, according to the balance of costs and benefits for the two partners of the interaction. These interactions involved the liberation of plant organic compounds via rhizodeposition. Modification of atmospheric CO2 concentration may affect rhizodeposition and as a consequence trophic interactions that bind plants and microorganisms. Positive effect of elevated CO2 on plants are rather well known but consequences for micoorganisms and their interactions with plants are still poorly understood. A gnotobiotic system has been developed to study the interaction between Medicago truncatula Jemalong J5 and the mutualistic bacteria Pseudomonas fluorescens strain C7R12 under two atmospheric CO2 concentrations: ambient (365 ppm) versus enriched (750 ppm). Costs and benefits for each partner have been determined over time by measuring plant development and growth, the C and N contents of the various plant parts and the density of the bacteria in rhizosphere compartments. Following the increase in CO2, there was a beneficial effect of P. fluorescens C7R12 on development, vegetative growth, and C/N content of M. truncatula. Concerning plant reproduction, an early seed production was noticed in presence of the bacterial strain combined with increased atmospheric CO2 conditions. Paradoxically, this transient increase in seed production was correlated with a decrease in bacterial density in the rhizosphere soil, revealing a cost of increased CO2 for the bacterial strain. This shift of costs-benefits ratio disappeared later during the plant growth. In conclusion, the increase in CO2 concentration modifies transiently the cost-benefit balance in favor of the plant. These results may be explained either by a competition between the two partners or a change in bacterial physiology. The ecosystem functioning depends on the stability of many plant-microbe associations that abiotic factors can disrupt

Plant N Fluxes and Modulation by Nitrogen, Heat and Water Stresses: A Review Based on Comparison of Legumes and Non Legume Plants

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Does root plasticity contribute to crop tolerance to abiotic stresses?

Poster that presents the experiments, the main results and take home messages

The roots of agriculture. To dig or not to dig: root phenotyping for breeding

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PPHD: une plateforme pour le phenotypage a haut debit

International audienceThe methodologies for genotyping and high throughput automated platforms for the production of type-omics (genomics, transcriptomics, protected omics ...) have greatly increased over the last few years and are now available to analyze the expression of genes of plants in several environmental conditions. However, a break of conceptual and technical services, non-destructive characterization and dynamic phenotypes, at the organ or plarite, has hundreds of related genotypes (Broadband) remains the limiting factor for the discovery of new characters or new varieties. This systematic exploration of diversity. Genetics within a species or between species requires platforms to characterize and automatically varied environments (biotic and abiotic) the phenotype of a large number of individuals from populations of mutants mapping, crosses and collections. The challenge is to achieve the flow rates in the production data from phenotyping, genotyping similar ones. The quantitative characters being observed - the components of the air architecture such as the number, size, shape and position of the leaves, for example - they require extremely precise control of changes in environmental parameters. Phenotyping Broadband is essential for genetic analysis of functional genes as specific particular reduces the time required for the discovery of new genes likely to generate important agronomic applications, such as changing the content of molecules, the composition and size of seeds and fruits, or tolerance to drough

Phenotyping Platform for Plant and Plant Micro organisms Interactions

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PPHD: a platform for phenotyping broadband

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