Response of the antioxidant system of wheat seedlings with different genotypes to exogenous prooxidants: the relationship with resistance to abiotic stressors

Abstract

Oxidative stress is an important component of heat- and drought-induced damage in plants. However­, information on the relationship between the resistance of cultivated plants with different genotypes to environmental factors and their ability to maintain a pro-/antioxidant balance remains contradictory. This study aimed to compare the growth responses and adaptation ability of the antioxidant system in different wheat cultivars to oxidative stress agents hydrogen peroxide and iron(II) sulfate. Etiolated seedlings of common winter wheat (Triticum aestivum L.) Antonivka and Tobak (heat- and drought-tolerant), and Avgustina and Doskonala (not resistant to heat and drought) were used for the study. Three-day-old etiolated seedlings were exposed to 50 mM H2O2 or 5 mM FeSO4 for one day. It was found that seedlings of Antonivka and Tobak cultivars treated with H2O2 or FeSO4 were able to maintain relatively intensive growth, accumulated significantly lower amounts of endogenous hydrogen peroxide and lipid peroxidation products, significantly increased anthocyanin content and had a higher activity of SOD and catalase as compared with non-resistant cultivars. The non-tolerant cultivars’ response to stress agents was only to increase proline content with a simultaneous decrease in SOD activity and anthocyanins content. The identified varietal markers of the antioxidant system adaptive strategy can be used to develop new approaches for screening wheat cultivars with cross-resistance to major abiotic stressors. Keywords: antioxidant system, drought resistan­ce, ferrous sulphate, H2O2, heat tolerance, oxidative stress, Triticum aestivum seedlings