P-210 - Retromer and SNARE-based membrane trafficking is essential for proper host invasion in rice blast

Rice is the most important staple food for almost half of the world’s population, but its production is severely threatened by infection with Magnaporthe oryzae. Effectors are the main weapons used by the blast fungus to attack the immune system of rice. Our study focuses on the molecular mechanism by which the vesicular retrograde transport machinery, retromer, regulates the sorting and transport of effector. We found that retromer mediates the transport of the cargo protein MoSnc1 (SNARE protein) from the vacuolar membrane to the surface of invasive hyphae after the fungal invasion in rice cells, thereby maintaining effector secretion and promoting colonization. In addition, the vacuolar SNARE complex (MoPep12-MoVam7-MoVti1-MoYkt6) and MoRab7 protein maintain vesicle trafficking by recruiting retromer to the vacuolar membrane, thereby promoting autophagy-dependent appressorium-mediated invasion and MoSnc1-mediated effector secretion. Molecular docking revealed that phenothiazine compounds can bind to a specific molecular pocket of MoVps1 (the protein responsible for the scission of retromer-coated vesicles). After treatment with phenothiazine, the pathogenicity of M. oryzae were significantly inhibited. This study elucidated the mechanism of vesicle transport during infection of the host by the rice blast fungus, and provided a theoretical basis for the development of new biocides or biological agents targeting vesicle transport in M. oryzae.