Effect of different selenium forms on the glutathione metabolism in wheat seedlings (Triticum aestivum L.)

Agronomic bio-fortification of wheat with selenium is a successful approach in improving its content in wheat grains. Due to its chemical similarity to sulphur, selenium is metabolized via sulphur assimilation pathways in plants. Therefore, in addition to oxidative stress induction, the application of selenium could also disturb protein structure and consequently influence glutathione metabolism in plants. Glutathione is involved in different processes such as biosynthetic pathways, detoxification of xenobiotics, antioxidant defence and maintenance of redox homeostasis. The aim of this study was to determine the impact of different concentrations of selenate and selenite on the glutathione metabolism in wheat seedlings (Triticum aestivum L.). For this purpose, contents of total, reduced and oxidised glutathione were determined, as well as the activities of the enzymes included in the glutathione metabolism such as glutathione reductase, glutathione peroxidase and glutathione S-transferase. Results showed that both forms of selenium affected total, reduced and oxidised glutathione content and activities of different enzymes in wheat seedlings. The glutathione content and enzyme activities depended on applied concentration of selenate and selenite. Both forms of selenium had more significant impact on the measured parameters in the root compared to wheat shoots, suggesting tissue-specific response. Obtained results can serve as a basis for further research on selenium toxicity and detoxification mechanisms in wheat. New insights into the selenium impact on glutathione metabolism could contribute to the further development of bio-fortification strategies.