MoWhi2 Participates in Mitophagy and Pathogenesis by Modulating MoAti1 Protein Level in Magnaporthe Oryzae

Rice blast caused by the fungus Magnaporthe oryzae is one of the most devastating diseases affecting rice production. It was previously demonstrated that MoWHI2 is indispensable for mitophagy and full virulence in M. oryzae , yet the molecular mechanisms underlying its control of mitophagy was unresolved. In this study, we found that MoWhi2 interacts with MoAti1, a SUN family protein that mediates mitophagy by recruiting autophagy-associated protein MoAtg8. Phenotypic analysis showed that the defects of Δ Mowhi2 /Δ Moati1 mutant in growth, conidiation, and pathogenicity were comparable to those of Δ Moati1 , but more severe than those of Δ Mowhi2 . Furthermore, compared with wild type, the Δ Mowhi2 /Δ Moati1 exhibited a lower mitophagy level similar to the single deletion mutants Δ Mowhi2 or Δ Moati1 . In addition, deletion of MoWHI2 resulted in decreased protein level of MoAti1, suggesting that MoWhi2 might regulate mitophagy by modulating the protein level of MoAti1. Due to absence of MoWhi2 orthologues in both rice and humans, we employed host-induced gene silencing (HIGS) targeting MoWHI2 in rice plants; the resultant transgenic rice lines displayed resistance to blast without agronomic penalties. Collectively, our data established that MoWhi2 regulates the mitophagy and pathogenicity of M. oryzae by interacting with MoAti1, and it could serve as a target for rice blast control strategies.