The plant microbiota: composition, functions, and engineering.

Plants growing in nature live in association with beneficial, commensal, and pathogenic microbes, which make up the plant microbiota. The close interaction between plants and their microbiotas has raised fundamental questions about plant responses to these microbes and the identity of the main factors driving microbiota structure, diversity, and function in bulk soil, in the rhizosphere, and in the plant organs. Beneficial microorganisms have long been used as inoculants for crops; the current development of synthetic microbial communities and the identification of plant traits that respond to the microbiota form the basis for rational engineering of the plant microbiota to improve sustainable agriculture.