P-522 - The molecular mechanism of histone acetyltransferase OsHAG704-mediated rice blast resistance

Histone acetyltransferases are well-known for modulating gene expression via histone acetylation, but how their functions in responding to Magnaporthe oryzae infection remains elusive. We showed that OsHAG704 is induced during incompatible or compatible M. oryzae-rice interaction, suggesting a role of OsHAG704 in regulating rice resistance against M. oryzae. In addition, we identified OsRpp30, a subunit of RNase P protein complex for tRNA processing, as a non-histone target of OsHAG704. OsHAG704 interacts with and acetylates OsRpp30. The acetylation on OsRpp30 does not alter its subcellular localization but promotes its stabilization via inhibiting its degradation. Consistently, overexpressing OsHAG704 in japonica rice Nipponbare enhances rice blast resistance, accompanied with increased hydrogen peroxidase accumulation. Moreover, co-expressing OsHAG704 in OsRpp30-overexpressed rice further promotes OsRpp30-mediated rice blast resistance. In conclusion, we identified a non-histone downstream target of OsHAG704 that is required to rice immunity against M. oryzae.