Involved in ascorbate homeostasis. Maintains redox pools of ascorbate by recycling dihydroascorbate (DHA) to ascorbate (Probable). Involved in scavenging reactive oxygen species (ROS) under oxidative stresses. Possesses dehydroascorbate reductase (DHAR) activity in vitro (PubMed:19011360). May function via a ping-pong reaction mechanism with an electron transfer at the active site (PubMed:26775680). Possesses chaperone-like activity in vitro (PubMed:26775680). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) 2 glutathione + L-dehydroascorbate = glutathione disulfide + L-ascorbate Monomer. Induced by heat shock (PubMed:10648822). Down-regulated during senescence (PubMed:25546583). Overexpression of DHAR1 improve ascorbate pool and redox homeostasis, and enhances grain yield and biomass in paddy field conditions. Belongs to the GST superfamily. DHAR family.