Figure 1. Model for the signal transduction of PTI mediated by RLCKVII family. Flg22 perception and signaling in Arabidopsis is shown on the left, and chitin perception and signaling in rice is shown on the right. FLS2 and OsCERK1 interact with BIK1/PBLs and OsRLCK185 in the absence of flg22 and chitin, respectively. Treatment with flg22 or chitin induces an interaction between BAK1 and FLS2 or OsCERK1 and CEBiP, respectively. This interaction leads to trans-phosphorylation of BIK1/PBLs and OsRLCK185 by the FLS2-BAK1 complex and OsCERK1, respectively. The phosphorylated BIK1/PBLs and OsRLCK185 dissociate from the receptor complexes and initiate downstream immune responses such as ROS production and gene expressions. OsRLCK185 but not BIK1/PBLs functions upstream of MAPK cascades.