May dephosphorylate and repress plasma membrane H(+)-ATPases (PM H(+)-ATPases, e.g. AHA1 and AHA2), thus influencing negatively plant growth and fitness. 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 SAUR19. Belongs to the PP2C family. Sequencing errors.