Glutathione S-Transferase Activity in Nontreated and CGA-154281- Treated Maize Shoots

Abstract

Abstract Fast protein liquid chromatography (anion exchange) was used to separate glutathione S-transferase isozymes in nontreated etiolated maize shoots and those treated with the herbi­cide safener CGA -1542814-(dichloroacetyl)-3,4-dihydro-3-methyl-2 H-1 ,4-benzoxazine. Non­treated shoots contained isozymes active with the following substrates: trans-cinnamic acid (1 isozyme), atrazine (3 isozymes), 1-chloro-2,4-dinitrobenzene (1 isozyme), metolachlor (2 isozymes) and the sulfoxide derivative of S-ethyl dipropylcarbamothioate (2 isozymes). Pre­treatment of shoots with the safener CGA -154281 (1 μM) had no effect on the activity of the isozymes selective for trans-cinnamic acid and atrazine but increased the activity of the constitutively-expressed isozymes that exhibit activity with 1-chloro-2,4-dinitrobenzene, metola­chlor and the sulfoxide derivative of S-ethyl dipropylcarbamothioate. The safener pretreat­ment also caused the appearance of one new isozyme active with 1-chloro-2,4-dinitrobenzene and one new isozyme active with metolachlor. The results illustrate the complexity of gluta­thione S-transferase activity in etiolated maize shoots, and the selective enhancement of gluta­thione S-transferase isozymes by the safener CGA -154281.