Displays a dual function. As a soluble protein, exhibits glutathione-dependent thiol transferase and dehydroascorbate (DHA) reductase activities (PubMed:12077129). Exhibits glutathione-dependent thiol transferase and dehydroascorbate (DHA) reductase activities. Key component of the ascorbate recycling system. Involved in the redox homeostasis, especially in scavenging of ROS under oxidative stresses. Plays a role in ozone tolerance. glutathione + RX = a halide anion + an S-substituted glutathione + H(+) 2 glutathione + L-dehydroascorbate = glutathione disulfide + L-ascorbate Monomer. By ozone. By salicylic acid (SA) (at protein level). Spontaneous S-glutathionylation in the presence of oxidized glutathione (GSSG). Mutant develops distinct foliar lesions under ozone exposure. Belongs to the GST superfamily. DHAR family.