THE EFFECT OF H2O2 PRE-TREATMENT ON ANTIOXIDANT ENZYME ACTIVITIES OF TRITICALE UNDER SALT STRESS

Widespread cultivated varieties Karma-2000 and Presto of Triticale were used in this study. The seeds were pre-treated with 0, 50, and 100 mu M hydrogen peroxide (H2O2) before sowing. Plants were treated with 0, 50, and 100 mM NaCl for salt stress when they were at the two-leaf stage. Different parameters related to stress responses were analysed such as relative leaf water content (RWC), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POX), and glutathione reductase (GR) enzyme activities, and thiobarbituric acid reactive substance (TBARS) and H2O2 levels were determined on the seventh day. Increases in GR, APX, and POX activities resulting from the antioxidant defence system contributed to the increase in tolerance to salt stress of the plants pre-treated with H2O2 during early seedling development. Pre-treatment with 50 mu M H2O2 improved the response of Triticale plants to salt stress by increasing the activity of the antioxidant defence system. In conclusion, H2O2 pre-treatment activated antioxidative enzyme activities which led to higher tolerance to salt stress in moderately salt-tolerant Triticale plant.