硒对砷胁迫下小白菜生理特性及砷吸收的影响  

Effects of selenium on the physiological characteristics and As uptake of pak choi under As stress

作　　者：赵秀峰[1] 张强[1] 程滨[1] 霍晓兰[1] 

机构地区：[1]山西省农业科学院农业环境与资源研究所,太原030031

出　　处：《环境科学学报》2017年第9期3583-3589,共7页Acta Scientiae Circumstantiae

基　　金：山西省自然科学基金(No.2015011079);山西省农业科学院博士研究基金(No.YBSJJ1502)~~

摘　　要：探讨硒对砷胁迫下小白菜生长及吸收砷的影响,可为调控植物吸收砷提供一定的科学价值.以小白菜为试验材料,采用水培方式,研究了不同砷胁迫水平下施加外源硒对小白菜生长、生理特性及砷吸收的影响.结果表明,低浓度硒(≤2.0 mg·L^(-1))对小白菜的生长有一定的促进作用,具体表现为小白菜株高、根长、地上部和地下部干重及叶绿素含量的增加,但高浓度硒(≥4.0 mg·L^(-1))却抑制了小白菜的生长.低浓度硒显著降低了小白菜叶片和根中丙二醛(MDA)的含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性.在砷、硒复合处理过程中,当小白菜中砷含量一定时,小白菜地上部和地下部砷含量随外源硒浓度的增加先减少后增加,且当外源硒浓度为2.0 mg·L^(-1)时最低.研究表明,施用2.0 mg·L^(-1)的硒缓解效果较好,能显著降低小白菜地上部砷的含量,促使砷富集在小白菜地下部,抑制砷向地上部的转运.The protective effect of selenium （Se） against arsenic （As） stress in pak choi （Brassica chinensis L. ） was investigated to provide scientific evidence for controlling the uptake of As. Hydroponic experiments were conducted to investigate the effects of exogenous Se on the growth, physiological characteristics and uptake of As by pak choi under As stress. The results showed that low concentrations of Se （ ≤2.0 mg·L-1 ） increased shoot height, root length, shoot and root biomass, and chlorophyll content in pak choi leaves. In contrast, high concentrations of Se inhibited the growth of pak choi. Low concentrations of Se significantly reduced malondialdehyde （MDA） contents and activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） in leaves and roots of pak choi. In the combined As-Se treatment, the content of As in shoots and roots of pak choi decreased first and then increased with the rising of Se concentration when As concentration was fixed, and the lowest As content in shoots and roots was recorded at the Se concentration of 2.0 mg· L-1. These results indicated that the application of Se at 2.0 mg· L-1 had good ameliorating effect against As stress in pak choi by inhibiting the transport of As from roots to shoots, thus leading to the enrichment of As in roots and considerable decrease of As content in shoots.

关 键 词：砷胁迫 硒 小白菜 生理特性 吸收 

分 类 号：X171.5[环境科学与工程—环境科学]