Cochliobolus heterostrophus T-toxin Gene Expression Modulation via G Protein and MAPK Pathways

摘要

The role of G-protein and mitogen-activated protein kinase (MAPK) in filamentous fungi has been studied for over a decade, but downstream elements are less known. Here, we used microarray and Northern blot analysis to examine the involvement of these signalling pathways in controlling the known Cochliobolus heterostrophus T-toxin biosynthetic gene, DEC1, whose control is important in epidemic prevention. Comparison of the expression profile in wild-type strains and in G-protein and MAPK signalling deficient mutants revealed a unique, environmental-dependent control mechanism for the DEC1 gene. The results suggest, for the first time, a possible role in pathogenicity for the G-protein alpha 2 subunit in this organism, and hint to a common role of G-protein alpha 1 and beta 1 subunits and MAPK in maintaining accurate levels of this toxin during pathogenesis.