Involved in the detection of CLV3 and CLV3-like (CLE) peptides, that act as extracellular signals regulating meristem maintenance. Acts with CLV3p as a ligand-receptor pair in a signal transduction pathway coordinating growth between adjacent meristematic regions and controlling the balance between meristem cell proliferation and differentiation. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Self-interacts. Interacts with CRN; this interaction is direct. Interacts with CLV3 and CLE2 mature peptides (MCLV3 and CLE2p, respectively) via its extracellular leucine-rich repeat region. In a central region of the shoot and in early flower meristems. Ectopic fruit organ initiation after floral meristem termination (PubMed:21705761). Enhanced disease resistance response to the bacterial pathogen Ralstonia solanacearum and to the biotrophic oomycete pathogen Hyaloperonospora arabidopsidis (PubMed:26990325). Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. Truncated N-terminus. Wrong choice of frame. Sequencing errors.