Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2018-2019)

The root-associated microbiome is a key determinant of soil nutrient availability, plant biomass productivity and pollutant degradation, but could not be examined in depth prior to recent advances in high-throughput sequencing and bioinformatics. Plant root-associated microbiome refers here to the whole community of bacteria and fungi living on the surface and/or inside plant roots. Arbuscular mycorrhizal fungi (AMF) constitute a widespread soil fungal group that establishes symbiotic associations with the majority of vascular plants. Once AMF colonize plant roots, they develop an extraradical hyphal network, promote nutrient uptake, in particular phosphorus and nitrogen, and protect plants against soil-borne pathogens. As fungi that extend their hypha into the rhizosphere and the surrounding soil, AMF not only interact with plants, but also with a myriad of soil microbes. Several in vivo and in vitro studies have shown that a large range of bacterial species live on the surface and/or inside mycelia, spores and intraradical propagules of AMF. Some fungal taxa belonging to Ascomycota and Chytridiomycota have also been reported to be associated with AMF mycelia.
My research program aims to determine the mechanisms by which AMF recruit, maintain and potentially alter their associated bacteria and fungi in response to biotic and abiotic challenge in nutrient cycling system with a particular focus on AMF biology. To that end, my lab will examine how microbes/AMF communities respond to changes in soil environment in terms of their functional activity; identify the association traits of bacteria and fungi closely interacting with AMF; and elucidate the mechanisms by which AMF attract or repel these microbes. We will also study AMF circadian rhythm and its potential synchronization with host-plant rhythmic oscillations (day and night) related to carbon cycling. My research team will use a highly reproducible greenhouse cultivation system with a combined analytical suite of amplicon sequencing, metagenomics and metatranscriptomics to address these objectives.
From a theoretical point of view, this research program will lead to a better understanding of soil microbial ecology and nutrient cycling. It will also yield fundamental insights into plant-microbe interactions and expand our knowledge of symbiotic organisms. AMF play an important role in soil biology. These ubiquitous fungi exist in almost all soil and play a central role in the functioning of ecosystems by forming mycorrhizae with more than 80% of plant species. The understanding of their biology is therefore a key factor in strategies to modify agricultural practices and enhance sustainable agriculture. Graduate students engaged in the proposed work will receive excellent interdisciplinary training in genomics, bioinformatics and soil microbiology.