Drought-induced plant microbiome and metabolic enrichments improve drought resistance

Plant-microbiome interactions are crucial in maintaining plant health and productivity under stress; however, little is known about these interactions under drought. Here, using wheat as a model, we combine genomics and culture-dependent methods to investigate the interactions between the soil, root, and rhizosphere microbiomes with rhizosphere metabolomes and plant phenotypes. We find that drought conditions promote microbial colonization in plant microbiomes, enriching Streptomyces coeruleorubidus and Leifsonia shinshuensis, while also increasing 4-oxoproline levels in the rhizosphere, potentially attracting S. coeruleorubidus. Consistently, genes facilitating microbial responses to drought, including the N-terminal acetyltransferase rimJ, are enriched, while S. coeruleorubidus and L. shinshuensis reintroduction promotes host drought resistance. Drought-legacy-effect experiments further support these benefits, with increased plant biomass and yield in the subsequent growth cycle under drought. Collectively, this study informs how drought-induced microbial and metabolite enrichments improve plant adaptation to abiotic stresses, potentially informing development of bio-based tools to mitigate drought effects.