Catalyzes the glutathionylation of 12-oxophytodienoate (OPDA). In vitro, possesses glutathione S-transferase activity toward 1-chloro-2,4-dinitrobenzene (CDNB) and benzyl isothiocyanate (BITC), and glutathione peroxidase activity toward cumene hydroperoxide. glutathione + RX = a halide anion + an S-substituted glutathione + H(+) By dehydration stress, salicylic acid, ethylene, methyl jasmonate, auxin, H(2)O(2), copper, benoxacor, isothiocyanates and the pathogen Hyaloperonospora parasitica. Belongs to the GST superfamily. Tau family.