中文摘要：

以SO2耐受性植物杜鹃（Rhododendron sp.）为材料,在2个高浓度SO2熏气后,检测了叶组织中丙二醛（MDA）、可溶性蛋白和叶绿素含量以及抗氧化酶活性.结果表明：40和80mg？m-3SO2熏气4h（1d）后,杜鹃叶片超氧化物歧化酶（SOD）活性和MDA含量均分别比对照显著增加了11.26%、11.86%和73.32%、76.43%;随熏气时间的延长,SOD、过氧化物酶（POD）、过氧化氢酶（CAT）活性持续增高,且SOD和CAT活性显著高于对照,MDA含量逐渐降至对照水平;SO2熏气导致叶片可溶性蛋白含量显著降低,但叶绿素含量却无显著改变.熏气后恢复期间,抗氧化酶活性相对降低,可溶性蛋白含量恢复至对照水平.研究发现,杜鹃对SO2的耐受性与细胞中抗氧化酶活性的诱导性增强有关,抗氧化能力增强是植物适应SO2胁迫的重要原因.

英文摘要：

Effects of SO2 on the activities of SOD,POD and CAT,and the contents of MDA,chlorophyll and soluble proteins were investigated in Rhododendron sp. The results showed that exposure to SO2 at concentrations of 40 mg · m^-3 a and 80 mg· m^-3 influenced the activities of antioxidant enzymes and the contents of MDA and soluble proteins in plant leaves. The activities of SOD,POD and CAT increased with SO2-fumigation and showed significant difference after a long term exposure,while the contents of MDA increased firstly and then returned to the control level with increasing antioxidant enzymes activity. The content of soluble proteins decreased,but no significant changes were found in the contents of chlorophyll after SO2 fumigation. However,activities of antioxidant enzymes decreased with a marked decline in MDA contents during 6-day recovery period after 7 day fumigation, while the contents of soluble proteins gradually returned to the control level. The present results suggest that the SO2-tolerance of plants was related to SO2 induced increase of the activities of antioxidant enzymes, and an enhancement of antioxidant ability might improve the adaptability of Rhododendron sp. to SO2 stress.