Causes and consequences of a conserved bacterial root microbiome response to drought stress.

Plant-associated microbial communities contribute to host fitness, and perturbations in the plant microbiome can have a major impact on plant health. Drought has recently been shown to lead to enrichment of monoderm bacteria within the roots of many plant species across many environments. However, the underlying causes of this shift, and the consequences for plant fitness, remain largely unexplored. We present the hypotheses that drought-induced shifts in plant metabolism may be responsible for the observed monoderm enrichment, and that increased monoderm abundance may promote increased drought tolerance in the host. Finally, we discuss how these recent discoveries may inform ongoing efforts to use microbially mediated strategies to improve crop productivity.