外源亚精胺对Hg2+胁迫下凤眼莲抗氧化系统的影响

通过Hoagland溶液培养实验,研究了外源亚精胺(Spd)(0.1 mmol?L-1)对Hg2+(0、10、20、30和40μmol?L-1)胁迫下凤眼莲叶片细胞内叶绿素、可溶性糖、可溶性蛋白含量及抗氧化系统的调节作用.结果显示,(1)随Hg2+处理浓度的升高,各处理凤眼莲叶片叶绿素a(Chl a)和叶绿素b(Chl b)含量均先升后降,并均在10μmol?L-1时达到最高值,但外源Spd处理组显著高于相应对照.(2)各处理凤眼莲叶片可溶性蛋白含量随Hg2+处理浓度的升高也呈先升后降趋势,而可溶性糖含量则呈持续上升趋势,但外源Spd处理亦明显高于相应对照.(3)随Hg2+处理浓度的升高,抗氧化物质AsA和GSH含量及抗氧化酶SOD、CAT、POD、APX及GR活性也均呈先升后降的变化趋势,而外源Spd处理植株的含量和活性均显著高于相应对照.(4)各处理凤眼莲叶片的H2O2、MDA含量及O2?-产生速率随Hg2+处理浓度的升高均持续上升,但在外源Spd处理后均比对照组下降.研究表明,Hg2+胁迫使凤眼莲生长受到严重伤害,外源Spd可大幅度地提高其抗氧化物质含量和保护酶活性,从而增强凤眼莲抗Hg2+胁迫的能力.

Effects of Exogenous Spermidine on Oxidation Resistance System in Eichhornia crassipes Leaves under Mercury Stress

Effects of exogenous spermidine(0.1 mmol·L-1) on the chlorophyll,soluble sugar,soluble protein contents and oxidation resistance system in leaves of Eichhornia crassipes under Hg2+(0,10,20,30 and 40 μmol·L-1) stress were studied.The results showed that,(1)with the increasing of Hg2+ concentrations,the contents of chlorophyll a,chlorophyll b increased at first and then decreased,and they reach the highest at 10 μmol·L-1 Hg2+,then exogenous spermidine lift the content of chlorophyll a and chlorophyll b.(2)The content of soluble protein increased at first and then decreased,the content of soluble sugar increased distantly,and the exogenous spermidine lift them.(3)The contents of AsA,GSH and the activities of SOD,CAT,POD,APX,GR increased at first and decreased later,exogenous spermidine lift them.(4)The content of H2O2,MDA and the generation rate of O-·2-increased distantly,and exogenous spermidine decreased them.So Hg2+ desoryded E.crassipes seriously,exogenous spermidine enhanced the resistance of Hg2+ in leaves of E.crassipes.