Abstract
ABSTRACT
Plant viruses have evolved sophisticated virulence strategies to counteract host antiviral defenses. Blue light, as an important environmental signal, can regulate plant growth and tolerance to biological stress. Nevertheless, how blue light regulates plant responses to antiviral immunity remains largely obscure. Here, we demonstrate that blue light suppresses rice black‐streaked dwarf virus (RBSDV) replication. The blue light receptor ZmPHR2 functions as a key immune component, positively regulating maize resistance to RBSDV. Mechanistically, ZmPHR2 interacts with ZmISP in chloroplasts to trigger a defensive reactive oxygen species (ROS) burst, thereby conferring resistance. The RBSDV effector P6 enhances the ZmPHR2‐ZmISP interaction, alters their subcellular distribution, and suppresses ROS accumulation. A functionally analogous P6‐OsPHR2‐OsISP module similarly mediates RBSDV resistance in rice. Our findings reveal that blue light perception directly activates antiviral defense pathways, uncovering a molecular basis for RBSDV resistance. This study provides a theoretical basis for artificially modifying the blue light receptor protein to enhance the resistance of cereal crops.