DROUGHT SHAPES THE DRYLAND ROOT METABOLOME AND MICROBIOME TO PROTECT AGAINST BIOTIC AND ABIOTIC STRESS

Climate change is among the most critical global concerns faced by farmers in the 21st century. Rhizosphere microbial communities (rhizobiome) positively influence plant fitness and offer much potential for improving crop resilience to drought and diseases. However, our understanding of the mechanisms through which water-stressed plants recruit rhizobacteria and the subsequent feedbacks of the rhizobiome to plant growth and fitness remains limited. We will address these gaps by focusing on the agroecosystem of the Inland Pacific Northwest, which currently experiences an unprecedented heat wave and drought. The overarching goal is to understand how water stress and crop monoculture shape the interactions between plants, microbial communities, and soilborne pathogens. We hypothesize that the dryland rhizobiome differs in metagenomic content from microbial communities of plants from well-watered soils and that the microbial adaptation to dryland conditions is mediated by changes in rhizodeposition. Our objectives are 1) to identify metagenome features associated with crop production under dryland conditions; 2) to characterize how root exudates mediate rhizosphere plant-microbe interactions under water stress; 3) to characterize the capacity of the dryland microbiome to control soilborne diseases and alleviate plant water stress.