Effects of elevated O3 and/or elevated CO2 on lipid peroxidation and antioxidant systems in Ginkgo biloba leaves.

Four-year-old seedlings of Ginkgo biloba were exposed to elevated O(3), elevated CO(2) and elevated O(3) plus elevated CO(2) in open-top chambers (OTCs) to study the responses of antioxidant system in Ginkgo biloba leaves. No significant changes in reactive oxygen production and scavenging systems were detected in seedlings exposed to high CO(2). Significant increase in H(2)O(2) and MDA content were induced by elevated O(3). The ascorbate content and antioxidative enzymes activity were increased significantly by exposure to high O(3) as well. But the promoted ability in scavenging did not prevent the increase in H(2)O(2) content and cell membrane lipid peroxidation. The increase was mitigated by high CO(2) in the combined exposure, but the effect was hardly significant.