May dephosphorylate and repress plasma membrane H(+)-ATPases (PM H(+)-ATPases, e.g. AHA1 and AHA2), thus influencing negatively plant growth and fitness (By similarity). Involved in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) signaling (PubMed:27494702). Negatively regulates immune responses by controlling the phosphorylation and activation status of BIK1, a central rate-limiting kinase in PTI signaling (PubMed:27494702). Impairs the phosphorylation of the NADPH oxidase RBOHD by BIK1 (PubMed:27494702). H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 magnesium or manganese ions per subunit. Interacts with BIK1. Phosphorylation at Ser-77 induces dissociation of PP2C38 from BIK1. Belongs to the PP2C family. Truncated N-terminus.