Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. Involved in the detoxification of certain herbicides. glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Homodimer or heterodimer of GST-I and GST-IV (=GST-II). Expressed in the stem and leaves, lower levels are seen in the pollen and endosperm. Belongs to the GST superfamily. Phi family.