Tri6 is a global transcription regulator in the phytopathogen Fusarium graminearum

In F. graminearum, the transcriptional regulator TRI6 is encoded within the trichothecene gene cluster and regulates genes involved in the biosynthesis of the secondary metabolite deoxynivalenol (DON). Targeted disruption of TRI6 confirmed its role as a positive regulator of trichothecene genes and previous studies designated Tri6 as a pathway-specific transcriptional regulator. The Tri6 protein with its Cys2His2 zinc-finger may also conform to the class of broad-domain transcription regulators. This class of global transcriptional regulators mediate various environmental cues and generally responds to the demands of cellular metabolism. Expression profiling of F. graminearum grown under nitrogen-limiting conditions revealed that 49 out of 198 target genes are differentially regulated by TRI6. The identification of potential new targets together with deciphering novel binding site for Tri6, casts new light into the role of this transcriptional regulator in the overall growth and development of F. graminearum. Overall design: Three biological replicates of Fusarium graminearum wildtype strain GZ3639 (NRRL 38155) (reference) and a tri6∆ mutant derived from GZ3639 were grown under nitrogen-limiting conditions in liquid culture for 5 hrs at 28oC