Functions redundantly with PCRK1 in basal resistance against bacterial pathogens and in regulation of plant immunity. Functions together with PCRK1 downstream of the pathogen-associated molecular pattern (PAMP) receptor FLS2. Contributes to the induction of SARD1 and CBP60G, which are transcriptional activator of ICS1, an enzyme involved in salicylate (SA) biosynthesis upon pathogen attack. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with FLS2. Induced by infection with the bacterial pathogen Pseudomonas syringae pv maculicola strain ES4326. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.