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United States Department of Agriculture

Agricultural Research Service

Title: A Genomic and Biochemical Approach to Trichothecene Diversity in Fusarium Sporotrichioides and Fusarium Graminearum

Authors
item Brown, Daren
item McCormick, Susan
item Alexander, Nancy
item Proctor, Robert
item Desjardins, Anne

Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 18, 2001
Publication Date: N/A

Technical Abstract: The trichothecenes T-2 toxin and deoxynivalenol (DON) are fungal natural products that are toxic to both animals and plants. Their importance in the pathogenicity of Fusarium spp. on crop plants has inspired efforts to understand the genetic and biochemical mechanisms leading to trichothecene synthesis. In order to better understand T-2 toxin biosynthesis by Fusarium sporotrichioides and DON biosynthesis by F. graminearum, we compared the nucleotide sequence of the 23-kb core trichothecene gene cluster from each organism. This comparative genomics allowed us to predict proteins encoded by two trichothecene genes, TRI9 and TRI10, that had not previously been described from either Fusarium species. Differences in gene structure were also correlated with differences in the types of trichothecenes the two species produce. Gene disruption experiments showed that F. sporotrichioides TRI7 (FsTRI7) is required for acetylation of the oxygen on C-4 of T-2 toxin. Sequence analysis indicated that F. graminearum TRI7 (FgTRI7) is non-functional. This is consistent with the fact that the FgTRI7 product is not required for DON synthesis in F. graminearum because C-4 is not oxygenated.

Last Modified: 9/21/2014
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