Protists at the plant-bacterial interface: Impacts and prospective applications

Protists are nonfungal eukaryotes that represent a vastly diverse component of plant microbial communities. Predatory protists provide plant microbiome ecosystems with nutrient recycling, culling and dispersal of the bacterial community, and selection and activation of microbial biocontrol or growth promoting traits, all functions important for plant health. Here, we briefly review protist interactions with bacteria in the rhizosphere, following topics discussed at the 12th Japan-US Seminar in Plant Pathology. We discuss how understanding of the specificity and signaling mechanisms of predator-prey interactions at the plant interface could be used to develop novel products and strategies for sustainable crop production.