摘要
在实验室将小羽藓(Haplocladium)暴露于不同浓度的铅、铁、铬重金属环境下进行培育,分别应用同步辐射X射线荧光(SRXRF)方法测定小羽藓植株硫元素的含量和X射线吸收近边结构(XANES)分析不同价态的硫所占的相对含量.结果表明,暴露于铅、铁下的小羽藓植株内硫的含量明显增加,铅、铁浓度分别为400 mg/L和200 mg/L时,硫元素含量下降.培养周期为15d时,小羽藓在100 mg/L铅胁迫下,低价硫由对照组的17.8%升高到23.6%,而同时以硫酸盐形式存在的硫由对照组的56.3%下降到51.2%.在400 mg/L铅胁迫时,低价硫含量增加到24.8%,硫酸盐中的硫所占的比例下降到48.4%.小羽藓植株内的胱氨酸、半胱氨酸、甲硫氨酸和谷胱甘肽中所含低价态硫的总相对含量增加,以硫酸盐态存在的硫相对含量明显下降.研究表明,重金属污染环境导致小羽藓硫吸收同化过程中硫元素含量和价态变化特征具有一定的生物指示作用.
Haplocladium was cuhivated in a special prepared nutrient medium containing different concentrations of Pb, Fe and Cr in laboratory. The sulfur content in moss was measured by synchrotron radiation X-ray fluorescence （SRXRF）, and the percentage of various oxidation states of sulfur was analyzed by X-ray absorption near-edge structure （XANES） spectrum. The results show that the sulfur absorption increases under exposure to heavy metal ions of Pb and Fe, but it decreases under exposure to 400 mg/L Pb and 200 mg/L Fe. When Haplocladium was cultivated for 15 days, under the stress of 100 mg/L Pb, the relative content of low oxidation states sulfur increases from 17.8% to 23.6% and the sulfate sulfur decreases from 56.3% to 51.2%. Under the stress of 400 mg/L Pb, the relative content of low oxidation state sulfur increases from 17.8 % to 24.8 %, and the sulfate sulfur decreases from 56.3 % to 48.4 % . Under heavy metal exposure, the total relative content of low oxidation states sulfur such as cystine, cysteine, methionine and glutathione increases, and the relative content of sulfate sulfur apparently decreases. All these results indicate that the changing characteristics of sulfur content and oxidation states percentage in sulfur assimilation process under heavy metal exposure can be used as a bioindicator of heavy metal pollution.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第12期3663-3668,共6页
Environmental Science
基金
中国科学院知识创新工程重要方向性项目(KJCX3-SYW-N3)
国家自然科学基金项目(10775170)
上海市科委重点项目(08390513800)
日本光子工厂KEK(2007G504)
北京正负电子对撞机国家实验室项目(VR-07004)
关键词
苔藓
重金属污染
生物监视器
同步辐射X射线荧光分析
X射线吸收近边结构谱
moss
heavy metal pollution
biological monitor
synchrotron radiation X-ray fluorescence（SRXRF）
X-ray absorption near-edge structure（XANES）
