The objectives for this study were to: (1) investigate the transcriptional activity of V. dahliae’s NoxA gene during both elicitation with host plant tissue extracts and during infection; (2) generate NoxA gene mutants in V. dahliae and analyze their phenotypes; (3) assess the roles of the NoxA gene in pathogen virulence and during the interaction with potato; and (4) determine its roles in cell wall biosynthesis and response to oxidative and osmotic stress. Here, PMAIP1 is linked to infection.