Protein phosphatase that negatively regulates defense respones. Inactivates MPK4 and MPK6 MAP kinases involved in stress and defense signaling. 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 MPK4 and MPK6. By wounding. High jasmonate production and PDF1.2 expression upon wounding. Slight reduction of lesion size caused by fungal pathogen. Slight decrease of spider mite reproductive performance. Belongs to the PP2C family.