RESCUE

Plant pathogens cause severe yield losses and compromise crop quality, safety, and nutritional value. To withstand diverse environmental biotic or abiotic constraints, plants have developed intricate immune and adaptive mechanisms. In addition to these molecular responses, plants interact with complex microbial communities, their microbiome, which can enhance growth and stress tolerance or, in contrast, trigger disease. Roots, in close contact with a dense and diverse microbial population, can actively modify their rhizosphere microbiome under stress conditions to recruit beneficial microorganisms. This adaptive mechanism, known as the “Cry-for-help” strategy, is mediated by dynamic changes in root exudates, a complex mixture of metabolites and proteins released into the rhizosphere. Emerging evidence indicates that plant genotypes play a major role in shaping microbial communities, particularly during stress conditions that trigger the “Cry-for-help” response. Understanding how host genetic factors influence the composition and structure of the plant microbiome is fundamental to decipher plant health and develop innovative microbiome-based strategies for sustainable agriculture. One of the main challenges is to uncover the cellular mechanisms that regulate root exudate composition and determine their impact on the rhizosphere microbiome during the “Cry-for-help” response. The RESCUE project is designed to address this key challenge. Using OMICs approaches, we aim to analyse the changes in metabolites and proteins composition in the root exudates of the model plant Arabidopsis thaliana when challenged with the necrotrophic pathogen Botrytis cinerea, a major plant pathogen. We aim to understand how these changes can influence the rhizosphere microbiota in the context of “Cry-for-help” mechanisms that promote plant defence and overall health. To this end, we will develop a reverse genetic approach to investigate whether these modifications are mediated by the plant secretory system. This project will focus on WP2 “Deciphering microbiota-host interactions” of the HARMI grant call. At the same time, it will provide important fundamental results for the longer-term goals of developing microbial biotechnologies in HARMI WP4.