Abstract: In order to explore the regulation of active oxygen metabolism and the response of antioxidant system in soybean root under enhanced UV-B radiation. Contrast with enhanced UV-B radiation through natural state,those was tested that the soybean roots' lipid peroxidation (malondialdehyde content and relative electrolytic conductivity),reactive oxygen species metabolism (super oxygen anion production rate and Hydrogen peroxide content),protective enzyme activity (superoxide dismutase activity,peroxidase activity and catalase activity) and protective substance content (ascorbic acid content,carotenoid content and proline content) of different growth stages of the soybean,and a series of different indexes were measured. The results showed that:compared with the control,enhanced UV-B radiation could cause O₂^· and Hydrogen peroxide accumulate. For specific performance,compared with CK,O₂^· producing rate and Hydrogen peroxide accumulating went down 11.5%,and went up 9.9% in florescence. The UV treatment was higher than CK in other reproductive period. Compared with CK,UV treatment was significantly different in all growth stages. And could lead MDA content and relative electrolytic conductivity to increasing. For specific performance,compared with CK,UV treatment was higher and significantly different in all growth stages for MDA content and relative electrolytic conductivity. And enhanced UV-B radiation conditions also could lead to protective enzyme activity reducing,such as SOD,POD and CAT. For specific performance,compared with CK,SOD,POD and CAT activity went up 15.5%,went down 15.3% and 12.8% for UV treatment in branch stage, other stages were lower. Compared with CK,UV treatment was significantly different except CAT activity in branch stage. Cause protective substances' content to decline,such as AsA,Car and Proline. For specific performance,compared with CK,AsA,Car and Proline content went down 11.4% and 15.4%,went up 10.5% for UV treatment in branch stage. And went up 31.2%,went down 17.9%,went up 20.7% in florescence. Other stages were lower. Compared with CK,UV treatment was significantly different except Car content in podding stage or proline content in branch stage. Therefore,enhanced UV-B radiation could cause the active oxygen metabolism and lipid peroxidation to speed up,membrane permeability to increase,and cause the antioxidant system to damage. And with the soybean growth period goes on,the effect moves obviously.

Key words: Plant physiological and ecology, Adversity damage, Contrast test, Enhanced UV-B radiation, Soybean's root, ROS, Antioxidative system

CLC Number: 

• S565.01