Ozone-induced changes in antioxidant systems of Ginkgo biloba in relation to the developmental stage of the leaves
Ozone (O3) pollution has adverse effects on the trees grown in urban area. Using open top chambers, responses of antioxidant systems were detected in Ginkgo biloba leaves at different developmental stages after a long term O3 exposure (O3 concentration ≈80 nmol mol -1). As leaf size is closely related to the developmental stage, leaves with different sizes were chosen to indicate the various developmental stages. The results suggested that activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) were induced to a higher level in younger leaves with 50% expansion size under elevated O3 exposure, whereas O3-induced decrease in APX and SOD activities was found in the 80% and 100% expanded ones. Dehydroascorbate reductase (DHAR) activity and ascorbate (Asc) content were not affected by high O3 in 50% expanded leaves, but the O3-induced decrease in them occurred in the 80% and 100% expanded ones. Malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents increased significantly in the 80% and 100% expanded leaves at elevated O3. However, O3-induced increase in MDA and H2O2 contents did not reach the significant level in the 50% expanded leaves, indicating the higher resistance to O3 in the younger leaves. The positive responses of antioxidant systems could be responsible for the higher resistance to O3 in the younger leaves.
Kun Yan Xingyuan He Wei Chen Tao Lu Kun Yan
Department of Urban Forest Institute of Applied Ecology, Chinese Academy of Sciences Shenyang, China Graduate School of the Chinese Academy of Sciences Beijing, China
国际会议
成都
英文
1-4
2010-06-18（万方平台首次上网日期，不代表论文的发表时间）