Glutathione reductase activity and chilling tolerance are induced by a hydroxylamine derivative BRX-156 in maize and soybean

dThe possible contribution of antioxidants in the improvement of stress tol erance induced by the hydroxylamine derivative BRX-156 was studied in two t hermophilic crops, soybean (Glycine max (L.) Merr.) and maize (Zea mays L.) both during germination and at the seedling stage. The most effective conc entration of BRX-156 for an increase in stress tolerance was determined by the complex stressing vigour test (CSVT), in which seeds were germinated un der simultaneous anoxia and chilling (5 degreesC) stresses. Under CSVT cond itions the activity of glutathione reductase (GR, EC 1.6.4.2), was increase d by BRX-156 by up to 200 and 150% in soybean and maize, respectively. Trea tment with BRX-156 only resulted in a significantly greater activity of glu tathione S-transferase (GST, EC 2.5.1.18) in maize. When young seedlings we re chilled at 5 degreesC for a week, the increase in recovery induced by BR X-156 was accompanied by increased GR activity. The GSH synthesis was not a ffected by BRX-156 under these conditions. Induction of GR activity contrib utes to the improvement of abiotic stress tolerance by BRX-156 in maize and soybean. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.