POTENCIJALNA ULOGA METABOLIZMA GLUTATIONA U SORTNO-SPECIFIČNOM ODGOVORU LISTOVA PŠENICE NA DVA RAZLIČITA IZVORA CINKA

During the early stages of grain development in wheat (Triticum aestivum L.) senescent leaves are one of the key sources of zinc for remobilization in grain, especially when grown under zinc-deficient conditions. Maintenance of high zinc concentrations in vegetative organs requires coordination of complex homeostatic mechanisms where glutathione plays a vital role as a chelating agent, antioxidant and signalling component. In order to investigate possible role of glutathione metabolism in maintenance of high zinc content in leaves, three winter wheat cultivars (Divana, Simonida and Srpanjka) were treated with two different forms of zinc fertilizer applied foliarly under field conditions. In flag leaves of all three tested cultivars zinc treatment did not significantly affect total glutathione content (GSH+GSSG). Though, variability in glutathione reductase and glutathione S-transferase activity, as in concentration of lipid peroxidation products, were cultivar-dependent and modified by the form of applied zinc fertilizer. Based on the obtained results, the treatment with zinc sulfate can be recommended as an effective wheat biofortification method as it significantly increase the concentration of zinc in the grain, while not causing the occurrence of oxidative stress in wheat leaves.