Abstract
Carbohydrate-binding malectin/malectin-like domain-containing proteins (CBMs) represent a newly discovered subclass of lectins that participate in various biological processes across the bacterial, animal, and plant kingdoms. The OsCBM1 gene in rice enhances reactive oxygen species (ROS) burst, contributing to drought-stress tolerance. Nonetheless, the functions of OsCBM1 in response to biotic stress remain poorly understood. In this research, we discovered that OsCBM1 was activated by Xoo infection, and overexpression of OsCBM1 increased rice resistance to bacterial blight, while suppression of its expression shows the opposite trend. OsCBM1 may influence resistance to bacterial blight by regulating ROS burst and the SA signaling pathway through RNA-seq analysis. Overexpression of OsCBM1 increased SA content and enhanced activities of SOD, POD, and CAT enzymes, whereas knockdown of OsCBM1 exhibited the opposite trend. The expression of genes associated with the SA and enzyme activity pathways was validated through quantitative real-time polymerase chain reaction (qRT-PCR). These results further clarify the function of OsCBM1 in biotic stress resistance, providing references for disease-resistant rice breeding.