Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 21 février 2019
Salle A Bât.1 à 11h
Plant-microbiome interactions: an ironic love story
Corné M.J. Pieterse
Plant-Microbe Interactions, Department of Biology, Utrecht University, the Netherlands
Plants nurture a large community of root-associated microbiota, which provide them with essential services, such as enhanced nutrient uptake, growth promotion, and protection against pathogens. Our research is focused on understanding plant-beneficial functions encoded by the root microbiome and the role of plant genes facilitating these functions. We demonstrated that upon foliar pathogen infection, Arabidopsis roots recruit a consortium of synergistic microbes to their rhizosphere that in turn trigger an induced systemic resistance (ISR) that is effective against a broad spectrum of pathogens (ISME J 12: 1496–1507; Cell 172: 1178-1180). Using the Arabidopsis-Pseudomonas simiae WCS417 model system, we identified the root-specific transcription factor MYB72 as a central regulator in the onset of ISR. Metabolome analysis revealed that MYB72 controls the biosynthesis of the iron-mobilizing coumarin scopoletin, which is excreted in the rhizosphere where it aids in iron uptake (PNAS 115: 5213-5222). Scopoletin also has antimicrobial activity to which WCS417 is insensitive. Microbiome analysis of coumarin-deficient mutants revealed that scopoletin functions in rhizosphere community assembly, possibly to promote recruitment of ISR-inducing rhizobacteria. Understanding the mechanistic basis of early root-microbiome interactions will provide a firm knowledge basis for the sustainable development of improved crop systems that maximize profitable functions from the root microbiome.
Contact : Florence vignols