LRR receptor kinase that may be involved in defense response. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with MSBP1. Localizes in the plasma membrane. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.