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以4年生的油松幼苗为试材,采用开顶箱内气体熏蒸实验,对经高浓度O3(80nmol.mol-1)和CO2(700μmol.mol-1)单一及复合处理3年后,油松当年生针叶内丙二醛(MDA)含量、活性氧自由基和抗氧化酶等逆境生理指标进行了分析。结果表明:超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)和脱氢抗坏血酸还原酶(DHAR)活性经O3处理后显著升高,分别比对照上升了43.1%、18.9%、283.5%和142.6%,而CO2和复合处理仅对APX和CAT活性有明显的诱导作用,但均低于O3处理;O3处理导致MDA含量上升51.8%,而外加CO2则能有效逆转这一趋势;超氧阴离子(O2.-)产生速率和H2O2含量在所有处理组合间均无显著差异。上述结果说明,O3能有效地激活油松当年生针叶内的抗氧化酶系统,而CO2能缓解O3所带来的不利影响,但并非通过提高抗氧化酶活性这一途径。
Using 4-year-old Chinese pine seedlings as test materials, the experiment of gas fumigation with open top was carried out. After three years of single and compound treatment with high concentration of O3 (80nmol.mol-1) and CO2 (700μmol.mol-1) The physiological indexes of malondialdehyde (MDA) content, active oxygen free radicals and antioxidant enzymes in needles were analyzed. The results showed that the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and dehydroascorbate reductase (DHAR) were significantly increased after O3 treatment, While the contents of MDA and MDA were increased by 43.1%, 18.9%, 283.5% and 142.6%, respectively. However, the activities of APX and CAT were significantly induced by CO2 and compound treatment, but both were lower than that of O3 treatment. O3 treatment resulted in the increase of MDA content by 51.8% This trend can be effectively reversed; the generation rate of superoxide anion (O2.-) and the content of H2O2 showed no significant difference among all treatments. The above results indicate that O3 can effectively activate the antioxidant enzyme system in Pinus tabulaeformis, while CO2 can alleviate the negative effect of O3, but not by increasing the antioxidant enzyme activity.