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Poster: Molecular & Cellular Plant-Microbe Interactions: Proteomics/Metabolomics/Genomics


Apple replant disease and the –omics: interaction of apple rootstock metabolome and the soil microbiome
R. Leisso (1), R. Leisso (2), M. Mazzola (2) (1) USDA-ARS, U.S.A.; (2) USDA-ARS, U.S.A.

Apple replant disease (ARD) negatively impacts tree health and reduces crop yield in new orchard plantings. Use of tolerant rootstock cultivars can diminish the growth limiting effects of ARD; however specific rootstock attributes enabling ARD tolerance are not understood. Systems biology tools were used to contrast root exudate biochemical profiles and corresponding soil microbial ecology between ARD tolerant and susceptible rootstock genotypes. A metabolomic approach utilizing LC-MS/MS QTOF was used to characterize water-soluble root exudate metabolites collected periodically from water percolated through rootstock roots planted in pasteurized quartz sand over 12 weeks. Soil microbial community profiling was conducted by terminal restriction fragment length polymorphism (TRFLP) or next-generation sequencing (NGS) on samples collected concurrently from soil with a history of ARD treated daily with the flow through exudates from rootstocks cultivated in quartz sand. Results indicate rootstock cultivars differ in both root exudate composition and quantity, and correspondingly soil microbial communities are altered in a rootstock genotype-dependent manner. Differences in exudate metabolome associated with ARD cultivar tolerance, and temporal dynamics of root exudate production and microbial populations during early stages of rootstock growth following dormancy, may offer insight into ARD tolerance and the early stages of disease development.