大气臭氧浓度升高对水稻叶片膜脂过氧化及保护酶活性的影响

采用开顶式气室（open top chambers，OTCs）装置，以水稻品种“3694繁”(Oryza sativa L.)为材料，研究3种处理：过滤大气（CF，O₃浓度约为20 nl·L^-1）、环境大气（NF，O₃浓度约为40 nl·L^-1）和高浓度O₃（EO，O₃浓度约为75 nl·L^-1）下叶片可溶性蛋白质含量、膜脂过氧化程度与主要保护酶活性的变化.结果表明：过滤大气与环境大气处理之间各个指标无显著差异.与CF处理相比，高浓度O₃处理条件下水稻叶片中可溶性蛋白含量显著下降，而过氧化氢（H₂O₂）和抗坏血酸（ASA）含量显著增加；超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活性升高，最大升高幅度分别为93.7%、39.9%和312.4%；抗坏血酸过氧化物酶（APX）活性呈先升高后下降趋势; 不同O₃处理条件下叶片中丙二醛（MDA)含量无显著变化.表明抗氧化系统可有效抑制水稻叶片中的O₃胁迫引起的膜质过氧化作用，说明水稻品种“3694繁”对O₃胁迫有一定抗性.

Effects of elevated ozone on rice (Oryza sativa L.) leaf lipid peroxidation and antioxidant system.

With rice (Oryza sativa L.) cultivar 3694 Fan as test material, and by using open top chambers, the effects of different ozone (O₃) concentration on the leaf soluble protein content, lipid peroxidation, and antioxidant system were applied. Three treatments were applied, i.e., charcoal-filtered air (CF, 20 nl O₃·L^-1), non-filtered ambient air (NF, 40 nl O₃·L^-1), and elevated O₃ (EO, 75 nl O₃·L^-1). The results showed that there were no significant differences in the test variables between treatments CF and NF. Compared with CF, EO induced a significant decrease of soluble protein content and significant increases of H₂O₂ and ASA contents and SOD, CAT and POD activities. In treatment EO, the SOD, CAT and POD activities increased by 93.7%, 39.9% and 312.4%, respectively, as compared with treatment CF, while the APX activity tended to increase at first and decrease then. MDA content had no significant differences among the treatments, indicating that leaf antioxidant system could significantly prevent the lipid peroxidation induced by elevated O₃, and rice cultivar 3694 Fan could resist O₃ to some extent.