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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL OF FUSARIUM MYCOTOXINS IN CORN, WHEAT, AND BARLEY

Location: Bacterial Foodborne Pathogens & Mycology Research Unit

Title: Heterologous Expression of Myrothecium Trichothecene P450 Oxygenase in Fusarium Verticillioides

Authors
item McCormick, Susan
item Alexander, Nancy

Submitted to: American Society of Pharmacognosy
Publication Type: Abstract Only
Publication Acceptance Date: August 6, 2006
Publication Date: August 6, 2006
Citation: Mc Cormick, S.P., Alexander, N.J. 2006. Heterologous expression of myrothecium trichothecene p450 oxygenase in fusarium verticillioides [abstract]. American Society of Pharmacognosy. P-022.

Technical Abstract: Macrocyclic trichothecenes are produced by certain fungi, including Myrothecium, as well as plants in the genus Baccharis. The unique structural features of macrocyclic trichothecenes make them 10-fold more toxic than the Fusarium trichothecenes. Myrothecium roridum has been previously reported to contain at least three trichothecene biosynthetic genes that are comparable to genes in Fusarium sporotrichioides, Tri4, Tri5, and Tri6, which produce T-2 toxin. The MrTri4 gene has 63% identity with FsTri4. Disruption of Tri4 results in the accumulation of trichodiene. We have recently shown that FsTri4 controls the first four oxygenations in Fusarium trichothecene biosynthesis. MrTri4 complemented a Tri4 mutant of F. sporotrichioides but did not result in a wild-type trichothecene profile, producing only minimal amounts of T-2 toxin. In this study, we expressed MrTri4 in Fusarium verticillioides, a species that does not produce trichothecenes, and found that exogenous trichodiene was converted to isotrichodiol. The results indicate that MrTri4 controls the first three oxygenation steps in Myrothecium macrocyclic trichothecene biosynthesis.

Last Modified: 9/23/2014
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