Overexpression of the sterol 14α‐demethylase gene (<i>MgCYP51</i>) in <i>Mycosphaerella graminicola</i> isolates confers a novel azole fungicide sensitivity phenotype

Abstract

The identification of an insertion in the predicted MgCYP51 promoter in azole-resistant isolates overexpressing MgCYP51 is the first report of a genetic mechanism, other than changes in target-site coding sequence, affecting sensitivity to multiple azoles in field isolates of M. graminicola. The identification of recent isolates overexpressing MgCYP51 confirms the ongoing evolution and diversification of resistance mechanisms in European populations of M. graminicola.