CSBZIP40

Citrus bacterial canker (CBC), a bacterial disease caused by Xanthomonas citri subsp. Citri (Xcc), is a serious threat to citrus production worldwide.. Molecular breeding with citrus canker resistance genes and susceptible genes is the most fundamental and effective measure to prevent and control canker disease at this stage. The previous study of our group showed that the level of reactive oxygen species (ROS) in citrus plants overexpressing CsBZIP40 (Cs8g15030.1) increased, and the canker resistance was significantly enhanced. However, the specific mechanism by which CsBZIP40 regulates ROS and canker resistance remains unclear. In this study, we screened the CsWRKY43 (Cs9g03310.1) and CsPRX53 (orange1.1t02041) downstream of CsBZIP40 and associated with CBC using transcriptome analysis, qRT-PCR, and Xcc-induced expression. To analyze the molecular mechanism of CsBZIP40 improving citrus canker resistance by regulating ROS homeostasis, we analyzed the interaction among CsBZIP40, CsWRKY43, and CsPRX53 by yeast one-hybrid, EMSA, and dual-luciferase reporter assay; reverified the functions of CsWRKY43 and CsPRX53 by genetic transformation of citrus, citrus transient expression and physiological and biochemical analysis.