Ecophysiological Characteristics Of Endogenesis Ascorbate And Glutathione In Different Life Cycle Forms In Catharanthus Roseus

Habitat heterogeneity which is induced by habitat conditions and disturbance degree is the main external factor in the forming of life cycle forms. The trade-off of energy in vivo of plant was allocated according to different properties of life cycle, results in the diversity of life cycle forms in plant. Ascorbate and glutathione, as important antioxidant system of plant, not only represent the degree of disturbance of the external environment in physiological level, but also indicate mutual transformation of various life cycle forms in substance distribution. In this study, the change of endogenous antioxidant ascorbate and glutathione contents in Catharanthus roseus leaves in different environments, the growth state and phenotype character were quantitatively and qualitatively analyzed respectively, to discuss the mechanism that endogenous antioxidant ascorbate and glutathione response to external environmental condition, and the interaction of antioxidant and the formation of C. roseus life cycle forms. The results of this study as follows:1. Light as an environmental factor involves in cellular oxidative metabolism by affecting the photosynthesis of leaves. In C. roseus ASC oxidation state level is higher when light is in Grade 6 than that in Grade 2, while the level of GSH is normal. It indicated that ASC is more sensitive to light factor in C. roseus.2. Determine ASC and GSH under the conditions of 40℃ and 28℃ respectively, we found that high temperature influenced GSH distinctly, but not obviously affected ASC. It attributed to that high temperature induced NADP coenzyme activity decreased and GSH oxidation-reduction system got disorder, resulted in GSH changed clearly.3.In drought experiment, C. roseus endogenous glutathione accumulates rapidly, but stomatal closure for long time and limits CO₂ assimilation and the excitation energy of photocativated chlorophy can not fix CO₂, and chloroplast ultrastructure destroyed, the plant agonal, the content of GSH descendes with the extend of treatment during heavy drought. When re-wartering one mouth for drought stress, GSH/GSSG still maitains higher, it suggests the damage of heavy drough stress is unreversible.4. In the experiment of exogenous ABA, GA and control water, ASC and GSH contents in the plant, which pretreated by water, was placed in the middle between pretreated by ABA and GA. It illuminates that GA and ABA are antagonistic for each other in redox state of C. roseus.Accordingly, in different living conditions, the response mechanism of C. roseus endogenous antioxidant ascorbate and glutathione are different. Further results in different environment, the effect of ascorbate and glutathione either independence or together to response the external environment disturbance during the development stage of C. roseus. Putthe response of ascorbate and glutathione to external environment disturbance in quantification. Reserch the interaction between endogenous antioxidant and the transformation of plant life cycle forms by the analysing of respond factor combinating principal components analysis (PCA). The resaults indicate that the antioxidant ability of ascorbate and glutathione is relationship with formation of C. roseus life cycle form. It proves the theory of prof. Zu in physiological level, because of diversity in the status of resource and the degree of disturbance composes different habitat, the habitat heterogeneity makes paint at different ecological amplitude, accordingly develops different plant life cycle form.