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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Genotype and chemotype profiles of endophytes associated with wild barley
M. YI (1), J. Kaste (2), N. Charlton (1), W. Hendricks (1), N. Krom (1), P. Nagabhyru (3), D. Panaccione (4), C. Young (1) (1) The Samuel Roberts Noble Foundation, U.S.A.; (2) Cornell University, U.S.A.; (3) University of Kentucky, U.S.A.; (4) West Virgin

The genetic and chemotypic diversity of Epichloë species (Clavicipitaceae, Ascomycota) isolated from wild barley (Hordeum spp.) was explored to provide potential valuable resources for forage improvement. We screened 56 wild barley PI lines from the US Department of Agriculture’s National Plant Germplasm System (USDA-NPGS), and identified 16 PI lines with endophyte incidence. Five distinct endophyte genotypes representing three nonhybrid and two hybrid Epichloë species were identified among the isolated endophytes from nine viable PI lines. Genotypes were identified based on the presence of alkaloid biosynthesis and mating type genes. Molecular phylogenetic analyses indicated that all nonhybrid genotypes are E. bromicola, whereas the two hybrid genotypes are E. bromicola by either E. typhina or an ancestor of E. amarillans or E. baconii. One of the hybrid genotypes was identified as a new taxonomic group currently referred to as HboTG-3. Alkaloid profiles were predicted from the genotyping data and the chemical profiles of distinct isolates were confirmed by HPLS and mass spectrometry with endophyte-infected plants, which confirmed the predicted chemotypes. Whole genome sequencing of four isolates provided insights for the complete alkaloid biosynthesis clusters in the wild barley endophytes and the unique features of the Epichloë species genomes. The beneficial effects each endophyte may provide the host will be tested under various biotic and abiotic stresses.