Induction of Oxidative Stress and Antioxidant Activity by Hydrogen Peroxide Treatment in Tolerant and Susceptible Wheat Genotypes

We induced an oxidative stress by means of exogenous hydrogen peroxide in two wheat genotypes, C 306 (tolerant to water stress) and Hira (susceptible to water stress), and investigated oxidative injury and changes in antioxidant enzymes activity. H₂O₂ treatment caused chlorophyll degradation, lipid peroxidation, decreased membrane stability and activity of nitrate reductase. Hydrogen peroxide increased the activity of antioxidant enzymes, glutathione reductase and catalase. These effects increased with increasing H₂O₂ concentrations. However, no change was observed in the activity of superoxide dismutase and proline accumulation.