Differential Responses of Antioxidative System to Soil Water Shortage in Barley ( Hordeum vulgare L.) Genotypes

Abstract

Drought is one of the major factors limiting the yield and quality of crops in the world. The activity of antioxidative system to tolerate the drought stress is significant in plants. In the present study, the activities and isoform profiles of catalase (CАТ), ascorbate peroxidase (APX), glutathione re-ductase (GR), and superoxide dismutase (SOD) were analyzed in four barley genotypes grown un-der soil water restriction. Drought stress caused increase in the activities of CАТ and SOD in all studied genotypes, while APX activity decreased. The total GR activity increased substantially in genotypes K 2778 and St.Garabag 7 and decreased in No. 77 local and St.Pallidum 596 genotypes under conditions of severe water stress. No detectable differences were observed in the isoen-zyme pattern (the appearance of a new isoenzymes and disappearance of another one) between control plants and those subjected to soil drought. However, intensification of corresponding iso-forms in electrophoretic spectra was observed in stressed barley leaves relative to watered ones. The obtained results possibly suggest that antioxidant protection in barley plants under drought conditions could be attributed mainly to SOD and CAT.