MECHANISTIC DRIVERS SHAPING ROOT MICROBIOMES AND MICROBIOME DRIVERS OF FITNESS BENEFITS IN DROUGHT-STRESSED PLANTS

Plants have evolved complex partnerships with microbes to enhance their tolerance to changing environmental conditions. Whereas our understanding of some of these partnerships is deep, we lack in-depth knowledge of the many other processes and partnerships that plants foster to withstand environmental stress. The long-term goal of this project is to exploit knowledge of plant microbiomes to enhance crop resiliency to abiotic stress. The project is based on the hypothesis that soil water deficits induce physiological changes in plants that directly modulate the developing microbiome within and on roots, and this modulation ultimately results in fostering microbiomes that aid plants to avoid and/or tolerate drought stress. The first objective of the work is to characterize the molecular mechanisms driving reproducible assembly patterns of root-associated microbiomes during the response of soybean to drought. This work will exploit the finding that drought stress induces repeatable shifts in the composition of root microbiomes in many plant species. The second objective is to identify the functional microbiome traits associated with feedbacks on soybean physiology and fitness under drought conditions. By identifying the linkages between stress-related soybean traits and phylogenetic and functional features of root-associated microbiomes, this work will broaden and enable strategies to exploit plant microbiomes for enhancing crop tolerance to drought.