engleski

Influence of different selenium forms on the antioxidative status in wheat seedlings (Triticum aestivum L.)

Selenium (Se) is an important microelement with a dual effect ; at lower concentrations it is an essential element for animals, humans and some lower plants, but at higher concentrations, it can become toxic. The aim of this study was to investigate the influence of different concentrations of two selenium forms, selenate and selenite, on the oxidative and antioxidative status of wheat shoots and roots. Wheat grains were exposed to five different concentrations(0.1 mg L-1, 1 mg L-1, 5 mg L-1, 10 mg L-1, 100 mg L-1) of Se in a form of selenite and selenate forseven days. As biomarkers of the oxidative status in wheat, lipid peroxidation (LPO) levels and total H2O2 content were determined. The antioxidative status was determined by total reduced glutathione levels (tGSH), as well as by catalase (CAT) and ascorbate peroxidase (APX) activities. Both Se forms did not cause any significant changes in LPO levels and H2O2 content in shoots, while in roots selenite and selenite induced oxidative stress. tGSH levels in roots and shoot were reduced after the exposure to various concentrations of selenite and selenate relative to their controls. The results showed that both forms of Se decreased CAT activity in roots, while in shoots CAT activity did not change. Furthermore, only the highest concentrations of selenite and selenite increased the APX activity in shoots and roots. In conclusion, the plant response to Se depends on its chemical form, applied concentration and the analyzed part of the plant. The obtained results can serve as a basis for further studies of molecular and biochemical effects of Se on plants.

selenate ; selenite ; wheat ; oxidative stress ; antioxidative enzymes

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