The StABI5-StCAT1 Module Regulates Potato Resistance to Early Blight Through the ROS Signaling Pathway

Abstract

Simple Summary Potato early blight caused by Alternaria solani poses a serious threat to potato yield and quality. Catalase regulates plant immunity against necrotrophic pathogens, yet its function in early blight remains unclear. In this study, A. solani infection induces hydrogen peroxide accumulation in plants, and exogenous H2O2 application markedly accelerates early blight infection. Furthermore, we identified StCAT1 as a positive regulator of resistance to early blight in potato, with its expression significantly upregulated following A. solani induction. Silencing StCAT1 impaired antioxidant capacity and disease resistance, while overexpression exerted the opposite effect. Additionally, StABI5 was identified as an upstream transcription factor that activates StCAT1 expression, and silencing StABI5 compromised potato resistance to early blight. These results indicate that StABI5 can activate the expression of StCAT1 and by mediating the reactive oxygen species (ROS) signaling pathway regulates potato resistance to early blight, which provides a theoretical basis and genetic resources for the molecular breeding of potato resistance to early blight.