Involved in oxidative burst-mediated signaling. Required for basal resistance to P.parasitica infection and root hair growth. Partly required for the activation of MPK3 and MPK6 by hydrogen peroxide and cellulase elicitor. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated in response to hydrogen peroxide and cellulase elicitor. Activated by PDK1 in a phosphatidic acid dependent manner. Interacts with PDK1 and PDK2. Expressed in roots and root hair cells. Highly expressed in fast-growing organs and dividing cells. By wounding, hydrogen peroxide and cellulase elicitor. The activation loop within the kinase domain is the target of phosphorylation. Plants have enhanced susceptibility to virulent P.parasitica pathogen and reduced root hair length. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family.