Oxidative stress and antioxidant metabolites in wheat (Triticum aestivum L.) varieties during grain development under water deficit conditions

Abstract

Two wheat (Triticum aestivum L.) varieties viz. WH 1105 and WH 1025 are subjected to drought stress. The non enzymatic antioxidant defense system which contains antioxidant metabolites such as ascorbic acid, glutathione and carotenoids contents were studied in drought sensitive and drought resistant varieties days after anthesis (DAA) in leaf and grain samples. As part of protective mechanism against drought, wheat plants produced more of ascorbic acid and glutathione with a concomitant decrease in carotenoid content. The increase in ascorbic acid and glutathione were more in WH 1025 than WH 1105. Carotenoids protect plants by minimizing ROS formation by quenching oxygen. The reduction in carotenoid content was observed in both wheat varieties days after anthesis (DAA) in leaf and grain samples but more reduction was observed in WH 1105 which is a drought sensitive variety of wheat. These antioxidant metabolites played a key role in protecting wheat plants against reactive oxygen species (ROS) mediated oxidative damage and their redox buffering capacity generates stress tolerance in drought tolerant wheat variety WH 1025.