Reactive Oxygen Species, Ascorbic Acid and Glutathione to Ozone Stress in Soybean (Glycine max) Leave

Open-top chambers were used to investigate the mechanism of antioxidants to eliminate reactive oxygen species and the impacts on growth and development of plants under troposphere O₃ stress. The results indicated that, compared to control, the O₃ concentration of O₃-1 (80±10nL·L-1) and O₃-2 (110±10nL·L-1) induced an increase on malondialdehyde content, relative electrical conductivity and a decrease on super oxide anion production rate, hydrogen peroxide during the whole growth stage. Simultaneity, O₃ stress resulted in lower content of ascorbic acid and glutathione, and higher content of dehydroascorbic acid and oxidized glutathione of AsA-GSH cycle. The results showed that antioxidant system can not tolerate oxidative damage caused by elevated O₃ concentration, thus increasing membrane lipid per oxidation, which represents injured effects to soybean.