镉胁迫对旱柳细胞膜透性和抗氧化酶活性的影响  

Membrane Leakage and Antioxidant Enzyme Activities in Roots and Leaves of Salix matsudana with Cadmium Stress

作　　者：杨卫东[1] 陈益泰[1] 

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江富阳311400

出　　处：《西北植物学报》2008年第11期2263-2269,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：浙江省科技厅重大项目(2006C12065)

摘　　要：以‘Fuyang 3’旱柳为材料,通过水培方法研究了中、高剂量(5、25μmol.L-1)镉胁迫下旱柳器官的镉(Cd2+)积累、叶和根细胞膜渗透及抗氧化酶活性的变化。结果表明:Cd2+主要积累在旱柳的根部(最高达1 297.71μg.g-1),其次是枝条(最高为163.13μg.g-1)。中、高剂量Cd2+胁迫下,旱柳叶相对电导率、根K+渗透以及根和叶丙二醛(MDA)含量均未发生显著变化。中、高剂量Cd2+胁迫使旱柳根系的超氧歧化酶(SOD)、抗坏血酸过氧化物酶(APX)和谷胱甘肽转移酶(GST)活性,以及叶片的SOD、愈创木酚过氧化酶(POD)、谷胱甘肽过氧化物酶(GPX)和GST活性均比对照显著增强;且高剂量胁迫旱柳根系的SOD和GST活性,及其叶片的POD、GPX和GST活性均显著高于相应中剂量胁迫。研究发现,旱柳在不同浓度镉胁迫条件下,其根是Cd2+主要积累器官,其叶和根细胞质膜能保持相对稳定性,其根和叶各抗氧化酶活性发生不同程度改变,从而使旱柳对Cd2+胁迫表现出一定的忍耐性。Salix rnatsudana cultivar ＇Fuyang 3＇ exposed to 5 and 25 μmol.L^-1 of Cd^2＋ for 21 d in hydroponic culture were analyzed with accumulation of cadmium in roots, cuttings and shoots, membrane leakages and antioxidative enzymes in roots and leaves. Higher accumulation of Cd^2＋ was found mainly in roots （the highest Cd^2＋ concentration was 1 297.71μg.g^-1 dry mass）. Secondly, high Cd^2＋ concentration was also observed in shoots （the highest value was 163.13 μg.g^-1）. Electrical conductivity of leaves,K^＋ elflux of roots and level of lipid peroxidation of roots and leaves were not significantly influenced under Cd^2＋ treatment. Changes in antioxidant enzyme levels in roots and leaves were examined,high levels of Cd^2＋ （25μmol.L^-1） significantly enhanced the activity of SOD in roots,Cd^2＋-induced SOD in leaves were showed more at all Cd^2＋ concentrations. The activity of APX in roots was observed increased compared with that of controls, but APX in leaves was not significantly changed. POD and GPX activities in leaves were markedly increased with Cd^2＋ levels in the medium. POD and GPX in roots were not significantly altered. Upon expo- sure to 5 μmol.L^-1 and 25 μmol.L^-1 Cd^2＋ ,GST prominently increased in roots and leaves. These results suggested that Cd^2＋ was accumulated mainly in roots,cell membranes in roots and leaves had considerably stability under Cd^2＋ stress,and the changes of antioxidative enzyme activities in Cd^2＋-treated had antioxi- dative function in Salix rnatsudana to Cd^2＋ stress.

关 键 词：旱柳 镉 膜脂过氧化 抗氧化酶 

分 类 号：Q945.78[生物学—植物学]