|Approaches to identifying and recovering plant microbiome components contributing to plant disease suppression
Brian McSpadden Gardener: Suståne Natural Fertilizer, Inc.
<div>For over a hundred years, plant pathologists have pursued three distinct approaches to searching the microbiomes to find allies in their fight to suppress disease and improve plant health. The random approach recovers and, then, screens as many different microorganisms as possible to find those that most ably suppress the pathogen or disease of interest. This approach led to the formation of the first biocontrol programs and companies, and, to this day, produced the most widely sold biopesticides in the marketplace. The mechanistic approach constrains searches to one or more activities that could be assayed, ecologically, biochemically, or genetically. This second approach provided new insights into the variation and distribution of biocontrol microbes, their genes, and active metabolites. Lastly, the phylogenetic approach quantifies associations between one or more microbial components, at varying levels of organization, to identify and then recover novel microbiome components involved in disease suppression. This approach has, more recently, yielded new candidate genes, pathways, and organisms that will someday further enhance biopesticidal and biostimulatory approaches to plant health promotion. Examples of how all three approaches have been successfully implemented over the years will be used to illustrate the potential and limits of harnessing the beneficial components of microbiomes to control plant diseases in various contexts.</div>