Fig. 3

Activation of OsRac1 by R protein plays a critical role in rice innate immunity. OsRac1 at the plasma membrane interacts directly with Pit, an NLR protein that confers resistance to rice blast fungus. OsRac1 contributes to Pit-mediated ROS production as well as the HR and is required for Pit-mediated disease resistance in rice. Furthermore, the active form of Pit induces the activation of OsRac1 at the plasma membrane. Thus, OsRac1 is activated by Pit during pathogen attack and plays a critical role in Pit-mediated immunity in rice.