Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Constitutively expressed in roots. Expressed in anthers, callus, panicles, sheaths and stems (at protein level). By the herbicide safener fenclorim. By drought stress. Belongs to the GST superfamily. Phi family.