Regulation Of Calmodulin On Antioxidative System Using Transgenic Tobacco Induciblely Expressing CaM

Tc-inducible CaM transgenic tobacco system was used as experimental material, which is firstly constructed by our laboratory in the world, to study the relation between CaM and the antioxidative system and to verify that CaM can directly regulate the antioxidative system.In the first section, we improved the quantitive assay method of plant CaM by PDE from many aspects, such as the extraction of PDE> the concentration of Ca2+ and cAMP *. the reaction time and the activity calculation. The improved method makes the extraction of PDE easier and more efficient, decreases experiment error and increases reaction stability, which supplys a good method for the quantitive assay of CaM content in the second section.In the second section, we studied the regulation of Tc-inducible CaM expression on antioxidative system. Firstly, in the experiment, we have found the CaM activity of control T2.3 was not changed with or without Tc inducement; But that of Tl.l increases by 90% without Tc inducement, comparing the control T2.3, while increases further by about 20% with Tc inducement. Secondly, as is the changing of CaM activity, with or without Tc, the antioxidative enzymes activity and the antioxidatants content of control T2.3 both remain unchanging. Comparing the control T2.3, some antioxidative enzymes(GPX, GR, SOD) activity and the antioxidatants content of Tl.l increase without Tc inducement, being induced by Tc, some antioxidaive enzymes(CAT, APX) activity of T1.1 rise,( but otherantioxidative enzymes(GPXN GR, SOD) activity and the antioxidatants content of T 1.1 retain growing significantly. However, with or without Tc inducement, the ratio of AsA/(AsA+DHA) and GSH/(GSH+GSSG) have no change. In a word, using the Tc-inducible CaM transgenic tobacco system, we have demonstrated that CaM can regulate the antioxidative system in plant.