Abstract

MYB transcription factors play important role in stress-resistance of plants. Nevertheless, the function of MYB TFs in peach Rhizopus rot remains poorly understood. Herein, Pichia guilliermondii treatment activated resistance against Rhizopus stolonifer , as illustrated by reductions in the incidence rate and severity of Rhizopus rot disease, increased enzyme activities and gene expression of chitinase (CHI) and β-1,3-glucanase (GLU), and enhancement of energy production by inducing the activities and expression of H + -ATPase and Ca 2+ -ATPase, succinate dehydrogenase (SDH), and cytochrome c oxidase (CCO). Moreover, an R1-type MYB, PpMYB1, from peach fruit was induced during R. stolonifer infection and in response to P. guilliermondii treatment. PpMYB1 activated the transcription of PpCHI-EP3 and PpGLU-like genes and the energy metabolism-related gene PpH + -ATPase1 by directly targeting the MBS element. Importantly, PpMYB1 interacted with PpNPR1 to form a heterodimer, which was conducive to enhancing the activation of target gene transcription . Collectively, our findings suggest that PpMYB1 cooperates with PpNPR1 to positively regulate disease resistance by activating the disease defense system and energy metabolism in peaches.