ARS | Publication request: Longiborneol Synthase Gene from Fusarium Graminearum is Required for Culmorin Biosynthesis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 26, 2009
Publication Date: June 26, 2009
Citation: McCormick, S.P. 2009. Longiborneol Synthase Gene from Fusarium Graminearum is Required for Culmorin Biosynthesis [abstract]. Gordon Research Conference.

Technical Abstract: A sesquiterpene cyclase gene, fg10397, was found in a Fusarium graminearum cDNA library that was previously used to identify trichothecene and butenolide biosynthetic genes. Gene disruption and add-back experiments showed that fg10397 was required for culmorin biosynthesis. Expression of fg10397 in yeast resulted in the production of longiborneol rather than the expected hydrocarbon longifolene. This suggested that the carbocation product of the sesquiterpene synthase is quenched with water to form longiborneol. Culmorin production was blocked and longiborneol accumulated in cultures treated with the P450 inhibitor xanthotoxin. Time course experiments with F. graminearum strains showed that longiborneol accumulated transiently in culmorin-producing strains. Longiborneol from F. graminearum is the stereoisomer of that found in plants. Preliminary greenhouse experiments suggest that culmorin may contribute to F. graminearum virulence on wheat.