Lectin-domain containing receptor kinase involved in salt stress response (PubMed:24907341). Acts as negative regulator of salt tolerance (PubMed:24907341). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Mainly expressed in root epidermal cells. Induced by salt stress. The gain-of-function mutant sit2-D (T-DNA tagging) exhibits reduced tolerance to salt stress. 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.