Identification and characterization of a NADPH oxidase target in Fusarium graminearum

Fusarium graminearum is a fungal plant pathogen that causes Fusarium Head Blight (FHB) on important cereal crops including wheat. Earlier studies identified distinct roles for NADPH oxidase (NOX) genes in F. graminearum. NOX enzymes generate reactive oxygen species (ROS) which are important in signal transduction. To elucidate the mechanism of NOX dependent signaling in pathogenicity, a proteomics approach was used to examine redox changes in the ΔnoxA/B mutant compared to wildtype F. graminearum strain. Deletion and overexpression of one of the candidate genes, FGSG_10089 with modified cysteine residues confirmed that it is likely a genuine substrate of the NOX enzyme complex. Bioinformatics and expression analysis indicate that this protein may function as a virulence factor. Deletion of FGSG_10089 and modification of the cysteine residue C325 resulted in reduced virulence on wheat. In addition, there was a decrease in production of 15-acetyl deoxynivalenol in culture.