PARylation of 14-3-3 proteins control the virulence of Magnaporthe oryzae

Magnaporthe oryzaeisa devastating fungal pathogen that causes the rice blast disease worldwide. The post-translational modification of ADP-ribosylation holds significant importance in various fundamental biological processes. However, the specific function of this modification in M.oryzae remains unknown. This study revealed that Poly(ADP-ribosyl)ation (PARylation) execute critical function in M. oryzae. M. oryzae Poly(ADP-ribose) polymerase 1(MoPARP1) exhibited robust PARylation activity. Disruption of PARylation by MoPARP1 knock-out or chemical inhibition revealed its involvement in M.oryzae virulence, particularly in appressorium formation. Furthermore, we identified two M. oryzae14-3-3 proteins, MGG_13806 and MGG_13806, as substrates of MoPARP1. Deletion of 14-3-3s resulted in delayed and dysfunctional appressorium, diminished plant penetration and virulence of the fungus. Biochemical and genetic evidence suggested that PARylation of 14-3-3s is essential for its function in M. oryzae virulence. Moreover, PARylation regulates 14-3-3 dimerization and is required for the activation of the mitogen-activated protein kinases (MAPKs), PMK1 and MPS1. 14-3-3 interacts with MPS1 and PMK1 in a PARylation-dependent manner. This study unveils a distinctive mechanism that PARylation of 14-3-3 proteins controls appressorium formation through MAPK activation, and could facilitate the development of new strategies of rice blast disease control.