Antioxidant potential of tolerant and susceptible wheat varieties under drought and recovery

Extreme environmental conditions are among the factors most frequently responsible for serious reduction in crop yield. Various abiotic stresses threaten wheat production worldwide and drought in particular is especially harmful when occurring at early vegetation phases. Four wheat varieties were compared with respect to their drought tolerance by withholding water in soil pot experiments and their ability to recover after re-watering was assessed based on changes in physiological and biochemical parameters. Drought caused significant decrease in leaf water content, increased the accumulation of hydrogen peroxide, malondialdehyde, free proline, and enhanced electrolyte leakage from cellular membranes. Water deprivation provoked oxidative stress which activated plants’ antioxidant defense system. The intensity of stress perception differed among the four wheat genotypes and they displayed diverse strategies for overcoming the imposed stress. While drought-resistant varieties responded to the stress via enhanced activity of ROS detoxifying enzymes, drought-sensitive genotypes employed coping mechanism involving accumulation of non-enzymatic components of the antioxidant defense system which were useful during the recovery process.