Regulates Infective Structural Differentiation Mediated by Physicochemical Signals from Pear Fruit Cuticular Wax, Stress Response, and Pathogenicity.

The high-osmolarity glycerol response kinase, , affects several cellular responses, but the precise regulatory role of the mitogen-activated protein (MAP) kinase in the differentiation of the infective structure of induced by pear cuticular wax and hydrophobicity has not yet clarified. In this study, the in was identified and functionally characterized. has threonine-glycine-tyrosine (TGY) phosphorylation sites. Moreover, the expression level of was significantly upregulated during the stages of appressorium formation of on the fruit-wax-extract-coated GelBond hydrophobic film surface. Importantly, our results showed that the appressorium and infection hyphae formation rates were significantly reduced in Δ mutants. Furthermore, is beneficial for the growth and development, stress tolerance, virulence, and cell-wall-degrading enzyme activity of . These findings may be useful for dissecting the regulatory mechanism in relation to the pathogenesis of .