Oral: Role of Phytobiomes in Plant Disease Control
The role of microbial communities in the development of the immune competency of plants.
S. HE (1) (1) Michigan State University, U.S.A.
Microorganisms have a broad spectrum of associations with plants. While select binary interactions have been studied in depth, notably pathogenic interactions and symbiotic nodulation of legumes, little is known about the dynamic functional relationship of a plant and its microbiome. As sessile primary producers rooted in soil, the richest microbial environment on Earth, plants must rely on an intricate innate immune system to recognize and respond to certain microbe-associated molecular patterns (MAMPs) for survival. Plants are constantly exposed to MAMPs in nature, yet the functional impact of this constant exposure remains elusive. To characterize the collective functional impact of the plant microbiome, we developed FlowPots: a unique gnotobiotic system that enables sensitive plant colonization assays and host phenotyping. Using the model host plant Arabidopsis thaliana, we germinate microbe-free seeds in substrate inoculated with various complex soil communities or defined bacterial microcosms. Profiling of the basal transcriptome and hormone quantification reveals compromised expression of immune-associated genes, and a series of immune assays reveals the reduced immunocompetence of gnotobiotic plants, compared to colonized plants. Collectively, our results indicate that the plant microbiome is necessary for normal immune function.