Induction of Glutathione S-Transferase Isozymes in Rice Shoots Treated with a Combination of Pretilachlor and Fenclorim.

Abstract

DEAE Sephacel anion exchange chromatography was used to separate glutathione S-transferase (GST) isozymes in non-treated etiolated rice shoots (4 day-old) and those treated with a combination of pretilachlor [2-chloro-2′, 6′-diethyl-N-(2-propoxyethyl)-acetanilide] and fenclorim (4, 6-dichloro-2-phenylpyrimidine).Non-treated rice shoots contained isozymes which were active with the following substrates; CDNB: 1-chloro-2, 4-dinitrobenzene (2 isozymes), fenclorim (2 isozymes) and pretilachlor (4 isozymes). Pretreatment of the shoots with a combination of pretilachlor and fenclorim increased the activity of the constitutively-expressed isozymes that exhibited activity with CDNB, fenclorim and pretilachlor. The treatment also induced two new GST(fen) isozymes and one new GST(pret) isozyme.The results are suggestive of the diversity of GST isozymes in etiolated rice shoots, the selective enhancement of GST isozymes by herbicides and safeners, and safeners conjugated with glutathione, resulting in selective safening action in rice.