Required during pollen development. Involved in resistance response to the pathogenic bacteria Pseudomonas syringae. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Low expression in young flowers (roughly before anther stage 6). Maximum levels around stages 6?7 that fade out gradually to a very low level in young siliques. Never detected in microspores or pollen. Male sterility due to defects in pollen development leading to deformed and collapsed nonviable pollen grains (PubMed:18392777). Increased susceptibility to the bacteria Pseudomonas syringae, characterized by stronger necrotic symptoms (PubMed:25083911). In the C-terminal section; belongs to the protein kinase superfamily. Ser/Thr protein kinase family. In the N-terminal section; belongs to the leguminous lectin family.