Antioxidant Isoenzymes Activities in Seedling Roots of Wheat Exposed to Drought Stress

This study was conducted to evaluate the role of oxidative stress in roots of eight wheat genotypes with different drought tolerance, subjected to drought stress. For analyzing the changes of antioxidant enzymes, native PAGE analyses of protein extract were performed. The roots of wheat seedlings showed one unambiguous isoform of superoxide dismutase (SOD) and catalase (CAT). Eight isoforms of peroxidase (POX) were identified in the roots of wheat. The activities of SOD and POX isoforms decreased and the total activities of POX and CAT remained unchanged under the stress condition. The response of enzyme isoforms to drought were not the same for all isoforms of the antioxidant enzymes in the wheat genotypes, as POX isoforms showed the significant changes in the different drought tolerant genotypes. Significant interaction was observed between wheat group and stress treatments for total POX activity. POX total activity in the sensitive group of wheat genotypes was significantly higher than the tolerant group in the stress condition.