Role of Sulphydral Compounds on Antioxidant Defense Mechanism under High Temperature Stress in Wheat

Abstract

The role of sulphydral compound viz: thiourea (TU) on the activities of antioxidant enzymes along with membrane thermostability parameters and metabolites contents was studied in high temperature (HT) stressed wheat (Triticum aestivum L. cv. PBW 343) seedlings. The seedlings were raised from seeds previously soaked with TU at different concentration (6 mM and 10 mM). TU pre-treatments modulated the response in shoots under HT by increasing antioxidant enzymes activities except superoxide dismutase and catalase, resulting in decreased lipid peroxidation products. In roots, HT upregulated the activities of ascorbate peroxidase and glutathione peroxidase but downregulated the activities of other enzymes resulting in increased TBARS levels. Proline content increased with TU pre-treatment in both shoots and roots under HT stress. Membrane thermostability was also enhanced with TU pre-treatment in both organs. However, free amino acids decreased with TU pre-treatment.