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Poster: Biology and Disease Management: Regulatory Plant Pathology


Functional genomic analysis of Botrytis cinerea isolates from Ohio
V. VIJAYAKUMAR (1), B. Cottrell (1), H. Reynolds (1), J. Slot (1), F. Hand (1), G. Valero (1), C. Tomashuk (1) (1) The Ohio State University, U.S.A.

Botrytis cinerea is one of the most widely spread phytopathogenic fungi displaying a broad host-range. While Botrytis is generally considered a model necrotroph, systemic symptomless infections have also been reported. Previous studies have shown significant genomic variation between gray and rare bikaverin producing pink isolates, but their contribution to diversity and host/pathogen relationships is understudied. We aim to elucidate genomic features of symptomless and host specific infections, and biochemically characterize virulence determinants. For this, we sequenced the genomes of 4 isolates from Ohio: 1 gray, isolated as asymptomatic endophyte of apple blossoms; 1 pink and 1 gray, isolated from infected flowers of Matthiola incana; and 1 purple, obtained from distinct sectors of pink isolate. We compared all 4 genomes to B05.10 and T4 reference genomes. Results showed large polymorphisms within coding regions of predicted genes (52,710, missense; 418 nonsense and 80,430 silent) and deletion of gene clusters (GC) associated with virulence. In both pink and purple isolates the botcinic acid GC was deleted, while in the gray asymptomatic isolate the abscisic acid GC was deleted. Investigation of virulence determinants among isolates showed a fully functional sclerotia formation, while the pink and purple strains alone were impaired in oxalic acid formation. Our results suggest that genetic diversity plays a significant role in species complexity and lifestyle.