土壤淹水抑制柳树根系Cu转运的作用机制研究

项目名称： 土壤淹水抑制柳树根系Cu转运的作用机制研究

项目编号： No.31470619

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 陈光才

作者单位： 中国林业科学研究院亚热带林业研究所

项目金额： 90万元

中文摘要： 速生树种柳树在土壤重金属污染修复中潜力巨大。对柳树吸收、积累重金属的能力和耐性研究也取得了一定进展。但是，现有结论多在溶液培养或旱地条件得到，不能充分反映耐水淹树种柳树与湿地土壤中重金属的作用规律。在前期研究基础上，本项目从淹水对土壤Cu的生物有效性的影响、对柳树的生长生理进而对重金属吸收的影响两个方面，系统地研究淹水时柳树对土壤中Cu的积累特征和转运机制。通过定量分析淹水土壤中Cu的形态及移动性，利用组织化学法，结合高效液相色谱、基于同步辐射装置的X射线吸收和荧光光谱技术，揭示柳树中Cu的形态和微区定位，阐明土壤淹水时柳树对Cu的吸收和积累特征。通过光合作用和蒸腾速率、运输通道中有机酸和植物络合素及Cu的测定，从转运驱动力和转运形态方面揭示柳树体内Cu的转运途径，并系统阐明土壤淹水抑制柳树根部Cu转运的作用机制。该研究对于了解树木与湿地土壤中重金属相互作用的某些规律及机制具有重要意义。

中文关键词： 土壤淹水；铜污染；柳树；积累；转运

英文摘要： Fast-growing Salix has great potential in phytoremediation of heavy metal polluted soil because of its traits. Most current researches focused on the absorption, accumulation and detoxification of heavy metals by willow under hydroponic solution or upland culture. However, most conclusions obtained from these above mentioned experimental conditions not adequately represent the interaction mechanism between wetland plants willow and heavy metals in wetland soils. To the best of our knowledge,the question as to whether and how soil flooding affects the absorption, accumulation,and translocation of heavy metals in willow has not been adequately addressed. Our previous results suggested that soil flooding significantly suppressed root-shoot translocation of copper by willow. Therefore, this proposal focuses on the mechanisms of accumulation and translocation of copper in willow, through the investigation of the bioavailability of soil copper, and the physiological responses, and copper chemical form and distribution in willow, which grow in flooded soil. X-ray absorption and X-ray fluorescence spectrum will be applied to obtain the direct evidence of micro-distribution,chemical form and coordinated structure of copper in different tissues of willow. The role of Fe/Mn oxide,S element and Fe/Mn plaques in copper accumulation in root will be analyzed. The translocation of copper through xylem and phloem pathways in willow grown in flooded soil will be evidenced. These results will clarify the mechanisms at molecular level on suppressed root-shoot translocation of copper in willow by soil flooding. The results will shed light on the mechanism between woody plants and heavy metals in wetland soils. It will also provide guideline to the application of willow in restoration and phytoremediaton of contaminated wetland.

英文关键词： soil flooding;copper;willow;absorption;translocation