[Effects of elevated O3 concentration and UV-B radiation on the chlorophyll content and active oxygen metabolism of soybean leaves].

Taking the soybean (Glycine max) cultivar Tiefeng 29 as test material, and by using open-top chamber, this paper studied the effects of elevated O3 concentration and UV-B radiation on the leaf chlorophyll content, lipid peroxidation, reactive oxygen species (ROS) production rate, anti-oxidation enzymes activities, and the grain yield. During the growth period of soybean, as compared with the control, the leaf Chl a, Chl b and Chl (a+b) contents under the stresses of O3 and UV-B had a decreasing trend, the relative electrical conductivity, malondialdehyde content, superoxide anion (O2) production rate, and hydrogen peroxide (H2O2) content increased, and the activities of superoxide dismutase, peroxidase and catalase as well as the grain yield decreased. O3+ UV stress aggravated the leaf membrane lipid peroxidation, promoted the ROS production, and decreased the plant antioxidant capacity and leaf chlorophyll content. The negative effects of O3 stress on soybean leaves were more close to the impacts of O3+UV stress, suggesting that O3 might play an important role in the combined stress.