Active as '1-Cys' thiol transferase against beta-hydroxyethyl disulfide (HED), as dehydroascorbate reductase and as dimethylarsinic acid reductase, while not active against the standard GST substrate 1-chloro-2,4-dinitrobenzene (CDNB). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) 2 glutathione + L-dehydroascorbate = glutathione disulfide + L-ascorbate By diamide and 1-chloro-2,4-dinitrobenzene (CDNB) in a transcriptional factors YAP1 and/or MSN2/4-dependent manner. Null mutants display increased sensitivity to cadmium in the absence of GTT1 and GTT2. Null mutants also show growth defects on oleic acid-based medium, indicative of abnormal peroxisomal functions and altered expression of genes related to sulfur amino acid metabolism, and have low levels of reduced glutathione. Belongs to the GST superfamily. Omega family.