Phosphatidylinositol-phospholipase C4 suppresses the hypersensitive response of .

Phospholipid signaling plays an important role in plant immune responses. Here, we isolated two phospholipase C4 (PLC4) orthologs in the genome, designated as and ( and ). We created and - silenced plants. Induction of the hypersensitive response (HR), including HR cell death and bacterial population reduction, was accelerated in both and -silenced plants challenged with -incompatible 8107. The and -silenced plants also showed enhanced expression of , a HR marker gene. Expressions of genes for salicylic acid (SA) and jasmonic acid (JA) signaling were drastically increased in and -silenced plants by inoculation. In addition, and silencing triggered reactive oxygen species (ROS) hyper-production. These results suggest that NbPLC4s are closely associated with JA, SA, and ROS signaling and act as negative regulators of the HR in