• 关键词：六溴环十二烷  对映体选择性差异  形态  抗氧化酶  γ-H2AX

• 基金项目：国家自然科学基金（No.21876043，21407041）；河北省自然科学基金（No.B2015208042）

• 武彤
• 1. 河北科技大学环境科学与工程学院, 河北省污染防治生物技术实验室, 石家庄 050018;2. 河北省药用分子化学重点实验室, 石家庄 050018

• 田柳
• 1. 河北科技大学环境科学与工程学院, 河北省污染防治生物技术实验室, 石家庄 050018;2. 河北省药用分子化学重点实验室, 石家庄 050018

• 崔建升
• 1. 河北科技大学环境科学与工程学院, 河北省污染防治生物技术实验室, 石家庄 050018;2. 河北省药用分子化学重点实验室, 石家庄 050018

• 马佳颖
• 1. 河北科技大学环境科学与工程学院, 河北省污染防治生物技术实验室, 石家庄 050018;2. 河北省药用分子化学重点实验室, 石家庄 050018

• 摘要：采用高效液相色谱法对α-六溴环十二烷（α-HBCD）对映体进行手性拆分，制备获得（+）-和（-）-对映体.以玉米为受试植物，利用水培实验方法，采用不同浓度梯度的（+）α-HBCD、（-）α-HBCD及（rac）α-HBCD溶液对发芽后的玉米幼苗进行暴露，开展α-HBCD对映体对植物生理和基因损伤作用研究.结果表明，不同α-HBCD对映体暴露后玉米根部形态发育异常，（+）α-HBCD处理的玉米根须明显稀疏；植物根部组织、地上部的生物量和长度的相对抑制率与暴露浓度线性相关，其中，（+）α-HBCD对玉米生长的抑制最强；玉米地上部叶绿素含量随α-HBCD暴露浓度的增加而显著降低，且降低量顺序为（+）α-HBCD > （rac）α-HBCD > （-）α-HBCD；低浓度的（+）α-HBCD显著诱导了玉米根部组织和地上部超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性，高浓度时则表现为显著的抑制作用，其中，SOD对α-HBCD胁迫反应更为敏感；组蛋白H2AX的磷酸化（γ-H2AX）水平呈现出不同的变化趋势，其中，（+）α-HBCD诱导γ-H2AX焦点数量增加最为显著.综上，α-HBCD对映体对玉米生理和基因水平均产生了选择性损伤作用，（+）α-HBCD的损伤作用强于（-）和（rac）α-HBCD.本研究可为综合评价手性HBCD的环境行为和生态风险提供重要信息.

• Abstract：Enantiomeric separation and preparation of α-HBCD were performed on high performance liquid chromatography (HPLC). The enantioselective physiological and genetic damage effects of α-HBCD on maize were investigated by hydroponic experiments. The germinated maize seedlings were exposed to different concentrations of (+)α-HBCD, (-)α-HBCD and (rac)α-HBCD solution in the present study. Results indicated that the root morphology of maize was abnormal after exposure to α-HBCD enantiomers. Early root development was more influenced by (+)α-HBCD than (-)-and (rac)α-HBCD. All the biomass and length of maize roots and shoots were inhibited, and the relative inhibition rates were positively correlated with the exposure concentration. The strongest inhibitory effect was observed in the (+)α-HBCD treatment. The chlorophyll content of maize shoots decreased significantly with an increasing exposure concentration of α-HBCD. The reduction were in the order of (+)α-HBCD > (rac)α-HBCD > (-)α-HBCD treatments. In contrast to (-)-and (rac)α-HBCD, the antioxidant enzyme activities of superoxide dismutase (SOD) and catalase (CAT) both in roots and shoots were significantly induced by exposure to lower concentrations of (+)α-HBCD and inhibited at higher concentrations. SOD was more sensitive to the stress reaction of α-HBCD. The level of histone H2AX phosphorylation (γ-H2AX) showed different trends with increasing concentration of α-HBCD enantiomers and racemate. The most significant induction of γ-H2AX was observed in the (+)α-HBCD treatment. All of these results demonstrated the significant physiological and genetic damage effects of α-HBCD enantiomers on maize with a higher effect of (+)α-HBCD than (-) and (rac)α-HBCD. The results of this study would offer important information for comprehensive assessment of the environmental behaviors and ecological risk of chiral HBCD.

• Key words：HBCD  enantioselectivity differences  morphology  antioxidant enzyme  γ-H2AX

• 
  摘要点击次数： 836 全文下载次数： 1138