P-161 - The Magnaporthe oryzae effector MoCRP1 suppresses rice immunity by targeting OsDyn4 to manipulate the plant mitochondria-mediated immunity

Mitochondria are the energy metabolism centers within cells and are also important organelles for cells to respond to both biotic and abiotic stresses. In the interaction between plants and pathogens, the dynamic changes and functional regulation of mitochondria play a crucial role. Here, we report that the effector MoCRP1 of the fungal pathogen Magnaporthe oryzae targets the mitochondria to reduce the plant defense response. Knockout of MoCRP1 in M. oryzae decreased the fungal infection ability, and overexpression of MoCRP1 in rice impaired the rice defense response. MoCRP1 localizes to the plant mitochondria, and its overexpression leads to a decreased number of mitochondria. MoCRP1 interacts with a rice dynamin-related protein (OsDyn4), a mitochondria-located GTPase enzyme that functions in mitochondrial fission. While OsDyn4 mutants exhibited weakened defenses, the overexpression lines demonstrated enhanced resistance, highlighting the critical role of OsDyn4 in blast resistance. The interaction between MoCRP1 and OsDyn4 promotes OsDyn4 degradation and decreased GTPase enzyme activity, resulting in fewer mitochondria and impaired mitochondrial function. In all, these findings uncover a novel counter-defense mechanism by which M. oryzae employs the effector MoCRP1 to suppress plant mitochondria-mediated plant immunity.