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

The possible contribution of antioxidants in the improvement of stress tolerance induced by the hydroxylamine derivative BRX-156 was studied in two thermophilic crops, soybean (Glycine max (L.) Merr.) and maize (Zea mays L.) both during germination and at the seedling stage. The most effective concentration of BRX-156 for an increase in stress tolerance was determined by the complex stressing vigour test (CSVT), in which seeds were germinated under simultaneous anoxia and chilling (5 degrees C) stresses. Under CSVT conditions the activity of glutathione reductase (GR, EC 1.6.4.2), was increased by BRX-156 by up to 200 and 150% in soybean and maize, respectively. Treatment with BRX-156 only resulted in a significantly greater activity of glutathione S-transferase (GST, EC 2.5.1.18) in maize. When young seedlings were chilled at 5 degrees C for a week, the increase in recovery induced by BRX-156 was accompanied by increased GR activity. The GSH synthesis was not affected by BRX-156 under these conditions. Induction of GR activity contributes to the improvement of abiotic stress tolerance by BRX-156 in maize and soybean.