Introduction Of Senescence-Inhabiting Gene Into Wheat (Triticum Aestivum L) Mediated By Agrobacterium Tumefaciens

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. We treated wheat seedlings with Na2SeOs on roots in order to find the effect of selenium on the growth of wheat seedlings and the relation of selenium and the activity of GSH-Px. The main results and conclusions were shown as follows:Selenium can enhance the synthesis of GSH-Px in seedlings. 0.5mg/l Na2SeO3 can increase the activity of GSH-Px on roots significantly. The activity of GSH-Px were 29.2% higher than that of control. 0.75mg/l Na2SeO3 can increase the activity of GSH-Px on leaves greatly.After treatment of 0.75 mg/1 NaaSeOa, the plant's height, weight, fresh weight and the contents of soluble sugar, soluble protein all enhanced. While the content of malndialdehyde and electrical conductivity decreased .The results showed that lower concentration of selenium can increase the growth of wheat seedlings, the accumulation of nutrient substance and enhance its resistance.GSH-Px is an important antioxidant enzyme. GSH-Px, POD, SOD, CAT and Vc et al. can protect the plant not to be injured by free radical. After treatment of NaaSeO3) the balance of the antioxidant system changed: The activity of GSH-Px increased. And the activities of SOD, POD and CAT decreased, while the contents of GSH and AsA increased.In order to find how Na2SeO3 enhancing the biosynthesis of GSH-Px, transcription inhibition Actinomycin D(AMD) and translation inhibitor cyclonheximide (CHM) were used. The results indicated that AMD and CHM can inhibit the synthesis of GSH-Px. 3 ng/1 AMD and 0.75 ng/1 CHM were the preferential concentrations for treatment. After treatd with AMD and Na2SeO3 72 hours, the activity of GSH-Px in roots decreased from 2.23 to 1.789 u mol/g. FW. min, and the activity of GSH-Px was 26.7% lower than that of control after treated with CHM and NaSeO3 72 hours. The results showed that Na2SeO3 can enhance the biosynthesis of GSH-Px not only by transcription but also by translation.