The mystery of the trichothecene 3-O-acetyltransferase gene:Tri101evolved independently of other trichothecene biosynthetic genes in the gene cluster

Abstract

Trichothecene resistance is achieved via 3-O-acetylation on the biosynthetic pathway of deoxynivalenol in Fusarium graminearum. The responsible 3-O-acetyltransferase gene, Tri101, was located between the UTP-ammonia ligase gene and the phosphate permease gene, and not in the trichothecene biosynthetic gene cluster. As predicted by the presence of its homologues in yeasts, the resistance gene proved to have evolved independently of other biosynthetic genes. In Fusarium sporotrichioides, FsTri101 (a functional homologue of Tri101) was also located these two ‘house-keeping’ genes. However, FsTri101 appeared not to play a pivotal role for self-resistance, suggesting that other defensive options are the primary working strategies for the type A trichothecene producer. © 1999 Society of Chemical Industry