Receptor-like kinase involved in the control of pollen germination and pollen tube polar growth (PubMed:23024212). Can phosphorylate ROPGEF1 in vitro (PubMed:23024212). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts in vitro with ROPGEF1 (via PRONE domain) (PubMed:23024212). Interacts weakly with the GRI peptide (PubMed:25398910). Expressed in pollen and/or in flowers, but not in leaves. The protein kinase domain may be catalytically impaired due to the lack of the conserved Asp active site at position 500, which is replaced by a His residue. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.