金属硫蛋白和外源硫酸盐在凤眼莲富集重金属中的协同作用

项目名称： 金属硫蛋白和外源硫酸盐在凤眼莲富集重金属中的协同作用

项目编号： No.41201510

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地理学

项目作者： 万小琼

作者单位： 华中农业大学

项目金额： 25万元

中文摘要： 环境中重金属污染常表现为多种重金属的复合污染，但仅少部分植物可以超富集两种或两种以上的重金属，凤眼莲就是其中之一。鉴于动物体内各类金属硫蛋白对多种重金属呈现生物活性差异和蛋白分子包围Fe-S原子簇结构中无机硫作用，申请者提出假设- - 凤眼莲对复合重金属的耐受性与其体内不同类型金属硫蛋白和无机硫的参与具有内在联系。通过对此假设的检验，可以重新认识凤眼莲在环境修复中的机理和地位。本项目拟以凤眼莲为对象，研究在单一或复合重金属胁迫下，外源硫酸盐对凤眼莲金属硫蛋白（EiMT）分子表达的影响、EiMT与单一或复合重金属的结合及分子结构变化，分析EiMT和无机硫在凤眼莲超积累重金属中的配位作用，系统解析植物中不同类型的金属硫蛋白和无机硫的生物功能及其环境效应。研究结果将丰富污染物迁移转化和植物金属组学理论，从污染生态化学角度理解水生态系统中植物对重金属的作用机制，为重金属污染水体的植物修复提供科学依据。

中文关键词： 凤眼莲；重金属；金属硫蛋白；外源硫酸盐；生物富集

英文摘要： Among the quite limited amount of heavy-metal hyperaccumulators known so far, Eichhornia crassipes (Mart.) is an outstanding phytoremediator of ecosystems contaminated concurrently by several heavy metals which are common in environmental pollution. Similar to the variety of bioactivities of metallothioneins for different heavy metals in animals and the participation of inorganic sulfide in Fe-S clusters of proteins in nature, different types of metallothioneins and inorganic sulfide in plants may be used for bioaccumulation of heavy metals. Here, we will investigate the hypothesis by studying the impacts of heavy metals together with sulphate on expression of metallothioneins in Eichhornia crassipes (Mart.) (EiMT). The coordination of both EiMT and inorganic sulfide to different metals as well as the corresponding structure will be characterized. The elucidation of biological functions and environmental effects of different types of metallothioneins and inorganic sulfide in Eichhornia crassipes (Mart.) based on the obtained results will provide more insights into transportation and transformation of pollutants, plant metallomics, mechanism of differential bioaccumulation of heavy metals by plants. This study may give some clues for enhancing phytoremediation of heavy-metal contaminated aquatic ecosystem.

英文关键词： Eichhornia crassipies；heavy metal；metallothionein；exogenous sulfate；bioaccumulation