中文摘要：

采用水培法通过测定大豆幼苗叶片和根的POD活性、MDA含量、H2O2含量，研究了酸雨（AR）和稀土La（Ⅲ）对大豆幼苗POD活胜和脂膜过氧化的复合影响。结果表明：单-La（Ⅲ）（RE1／20mg／L、RE2／60mg／L、RE3／100mg／L、RE4／300mg／L）处理时，低剂量La（Ⅲ）（RE120mg／L）处理下，叶和根中POD活性高于CK而MDA和H2O2含量较之降低，高剂量La（Ⅲ）（RE2／60mg／L、RE3／100mg/L、RE4／300mg／L）处理下，叶和根3项指标均升高。在酸雨（AR1/pH2．5、AR2／pH3．5和AR3／pH4.5）单独作用和RE＋AR复合作用影响下，叶和根3项指标均升高；而且AR的pH越低，RE的浓度越高，叶和根中的3项指标增幅越大。RE1和AR复合处理下叶和根中3项指标的增幅低于AR单-处理，其它浓度RE和AR复合处理叶和根中的3项指标增幅高于各自单独作用。单一酸雨处理组各指标变幅为叶〉根，单一镧和复合处理组各指标变幅为根〉叶。

英文摘要：

Combined effects of acid rain （AR） and rare earth element La（ Ⅲ） on the peroxidase （POD） activity and lipid membrane peroxidation in soybean seedlings were studied by hydroponics under laboratory conditions. Results showed that single AR（AR1/pH 2.5, AR2/pH 3.5, AR3/pH 4,5） treatment resulted in an increase in POD activity, hydrogen peroxide （H2O2） content and malondialdehyde （MDA） content in both leaves and roots, and showed an obvious dosage-effect relation. The decreased degree of each index in leaves was higher than that in roots. For single treatment with La（ Ⅲ ） （RE1/20 mg/L）, H2O2 content and MDA content in leaves and roots were all decreased, while POD activity increased, compared with those of the control. For single treatment with RE2-RE4 （RE2/60 mg/L, RE：3/100 mg/L REal300 mg/L）, H202 content, MDA content and POD activity in leaves and roots were all increased. Compared with single treatment with AR or La（ Ⅲ ）, the increased degree of each index in leaves and roots treated with AR＋ La（ Ⅲ ） （RE2-RE4） was higher, showing a synergy effect.