Respective and interactive effects of doubled CO_2 and O_3 concentration on membrane lipid peroxidation and anti- oxidative ability of soybean

摘要

Effects of doubled CO_2 and O_3 concentration on Soybean were studied in open-top chambers (OTC). Under doubled CO_2 concentration, grain yield and biomass increased, the SOD activity, vitamin C (Vc) and carotenoid (Car) content also increased; Superoxide (O_2~(-.)) generating rate decreased, relative conductivity and malondialdehyde (MDA) content significantly declined. But under doubled O_3 concentration, the SOD activity, Vc and Car contents declined, resulting in imbalance of activated-oxygen production, enhanced O_2~(-.) generating rate and accelerated process of lipid peroxidation and increase in MDA content and ion leakage of leaves. The final result was decreased grain yield and plant biomass. Interactive effects of doubled CO_2 and O_3 concentrations on soybean were mostly counteractive. However, the beneficial effects of concentration-doubled CO_2 are more than compensate the negative effects imposed by doubled O_3, and the latter in its turn partly counteracted the positive effects of the former.