重金属跨膜吸收的通道转移机制及电生理特征

项目名称： 重金属跨膜吸收的通道转移机制及电生理特征

项目编号： No.31272228

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 封克

作者单位： 扬州大学

项目金额： 80万元

中文摘要： 为提高植物食品的安全性和利用植物修复重金属污染土壤，需要追踪有关的功能基因以培育具有特殊功能的所需植物。为此首先应寻找重金属在吸收进入细胞过程中所表现出的生理特征，但迄今对其跨膜转移机制的了解还欠清晰。本研究拟采用具有不同抗逆机理（机理I和机理II）和不同重金属积累能力的植物基因型作为实验材料，利用代谢抑制剂和通道抑制剂以及离体细胞酶测定等生物化学方法，离子选择性微电极等电生理测定技术，配合营养吸收动力学和木质部液汁收集等研究手段，对三种典型重金属（Cd、Cr、Cu）的跨膜转移过程进行研究，搞清它们是以离子态还是络合态被植物吸收，在跨膜进入细胞时与其他阳离子竞争位于细胞膜上的哪些离子通道，哪些环境或代谢因子影响它们的跨膜转移等问题。通过研究，鉴别出它们在跨膜转移过程中所表现出的特有生理特征，为进一步追踪参与调节的功能基因和在此基础上采用分子生物学手段挖掘植物排斥或积累重金属的潜能提供参考。

中文关键词： 重金属；根吸收部位；膜电位；质子泵；离子选择微电极

英文摘要： In order to assure safety of food products of plant origin and to amend the soils polluted by heavy metals, it is necessary to track relevant functional genes so as to develop the required plants with specific functions. The primary step towards this target should be to understand the physiological characteristics (including the pathways for transmembrane transport, factors affecting the transport process and changes of relevant physiological parameters) of heavy metals during their entrance into plant cells. Real uptake of heavy metals is theoretically confined to the physiological process that the heavy metals enter the cytoplasm across membrane, rather than to the adsorption on root surface and chemical deposition in water free space of the apoplast. However, the mechanisms pertaining to the transmembrane transport of heavy metals have not been so clear yet, and some previous reports are even contradictory. In this project, different genotypic plants with various stress-tolerant strategies (Strategy I and Strategy II) and with differed ability in heavy metals accumulation are to be used as materials to respectively investigate the transmembrane transport process of three typical heavy metals (Cd, Cr and Cu), using biochemical methods including the use of metabolic and channel inhibitors and in vitro assessmen

英文关键词： heavy metal；adsorption part of root；ion selective electrode；membrane potential；H+-ATPas activity