TRI8 ENCODES AN ESTERASE REQUIRED FOR FUSARIUM TRICHOTHECENE TOXICITY

Authors: McCormick, Susan; Alexander, Nancy

Submitted to: Phytochemical Society of North America Meeting and Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 8/8/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Trichothecenes are sesquiterpene epoxide mycotoxins produced by several genera of fungi including Fusarium, as well as the plant genus Baccharis. Trichothecenes act as potent inhibitors of eukaryotic protein synthesis and have been shown to be phytotoxic and important factors in plant diseases such as wheat head scab. Their biosynthesis requires adaptations by the producing organisms for self-protection. Both F. sporotrichioides and F. graminearum have a resistance gene, TRI101, which encodes a transacetylase that acetylates the C-3 hydroxyl group of trichothecenes. Biosynthesis of Fusarium trichothecenes is via a series of intermediates that are acetylated at the C-3 position. C-3 acetylated trichothecenes are significantly less toxic than their C-3 hydroxyl analogs. The release of toxic trichothecenes into the host plant requires removal of the protecting group. We have identified and characterized TRI8, the gene encoding the esterase that removes the acetyl group.