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


Comparative genomics of S and L morphotypes of Aspergillus flavus
M. OHKURA (1), M. Ohkura (1), P. Cotty (2), M. Orbach (1) (1) School of Plant Sciences, University of Arizona, U.S.A.; (2) Agricultural Research Services USDA, University of Arizona, U.S.A.

Strains of Aspergillus flavus vary greatly in their level of aflatoxin production and atoxigenic strains are not uncommon in nature despite the fungus’ notoriety for producing the carcinogenic mycotoxin. Aspergillus flavus strains are of two morphotypes; the S morphotype that produces numerous small sclerotia and limited conidiospores and the L morphotype that produces relatively fewer large sclerotia and abundant conidiospores. S strains are consistently toxigenic, whereas L strains vary greatly in toxin production ranging from atoxigenic to highly toxigenic. This suggests the two morphotypes have adapted to different niches where selection pressure to maintain aflatoxin production is high in the environment the S strains inhabit, and low in which the L strains inhabit. To develop hypotheses on differential niche adaption, we compared the genomes of three S strains and three L strains to identify genes unique to each morphotype. A notable difference in secondary metabolite genes was observed and the results from the comparative genomics analyses will be presented.