Forms a complex with CRK45 that may negatively control abscisic acid (ABA) and osmotic stress signal transduction. Can phosphorylate CRK45 in vitro (PubMed:22225700). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with CRK45. By ozone and light stress (PubMed:20500828). Induced by salt stress, drought stress and abscisic acid (ABA) (PubMed:22225700). Autophosphorylated. Seedlings silencing CRK36 show increased sensitivity to abscisic acid (ABA) and salt stress during post-germinative growth. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. CRK subfamily.