Involved in the regulation of procambium maintenance and polarity during vascular-tissue development (PubMed:17570668). Phosphorylates HIRD11 and LHCA1 in vitro (PubMed:25602612). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with HIRD11. Reduced procambial cells number, and adjacent or interspersed xylem and phloem formation. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.