Studies On The Mechanism Of Sodium Selenite-Induced Glutathione Peroxidase Biosynthesis Of Wheat Seedlings

Glutathione peroxidase (GSH-Px) is a selenium-dependent enzyme which was found in animal cells at first and has been discovered in many plants in recent years. Some researchers found that preferential concentrations exogenous Se increased the activity of GSH-Px. We treated wheat seedlings with sodium selenite (Na2SeO3) on roots in order to find the effects of selenium on the activity of GSH-Px and combined with the transcription inhibitor Actinomycin D (AMD) and the translation inhibitor Cyclonheximede (CHI) to study the mechanism of sodium selenite-induced GSH-Px biosynthesis.The results showed: 1.0 mg/L sodium selenite treatment increased the activity of glutathone peroxidase remarkably and higher concentrations could inhibit the activity of GSH-Px. Application of two inhibitors (Actinomycin D and Cycloheximede) combine with sodium selenite showed that 1. 0mg/L sodium selenite could promote the expression of gene. Through the polyacrylamide gel electrophoresis (PAGE), it could be see directly. It demonstrated that there are some effects of sodium selenite on the biosynthesis of glutathone peroxidase.The results showed that the GSH-Px activity, GST activity and the GSH level in the wheat seedlings treated with preferential concentrations exogenous Se (1.0 mg/L sodium selenite) were higher than that of the control seedlings. And GST activity changed with cultural time, not increase, but decrease, which is different from GSH-Px activity. This means that there are some special relationship between GSH-Px and GST.Effects of sodium selenite (Na2SeO3) of different concentrations (0.5,1.0, 2.0, 4.0,10.0 mg/L) on elimination ability of hydroxyl free radical and superoxide anion free radical in wheat seedlings were studied in this note. The results showed that low sodium selenite level can increase the elimination ability of hydroxyl free radical and superoxide anion free radical in wheat seedlings, and 1.0 mg/L Na2SeO3 has the best effect. However, with the increasing concentration of Na2SeO3, the elimination ability of hydroxyl free radical and superoxide anion free radical decrease correspondingly.