The trichothecene biosynthesis regulatory gene from the type B producer Fusarium strains: Sequence of Tri6 and its expression in Escherichia coli

A genomic DNA fragment containing Tri6, a transcription activator gene of t richothecene biosynthesis, was cloned by vectorette PCR from Fusarium grami nearum F15, which produces type B trichothecene, deoxynivalenol. The nucleo tide sequence of the gene showed 84% of identity to that of the type A tric hothecene producer Fusarium sporotrichioides NRRL 3299, but the sequence ar ound the initiation codon was not highly conserved between these producers. Based on the upstream and downstream sequences of the coding region of F. graminearum, Tri6 could be amplified by PCR from other type B trichothecene producers. Tri6 appeared to be expressed for only a limited period prior t o the toxin production.