超积累植物根系分泌物与根际微生物的相互作用及其对重金属活化吸收的影响

项目名称： 超积累植物根系分泌物与根际微生物的相互作用及其对重金属活化吸收的影响

项目编号： No.41271333

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 李廷强

作者单位： 浙江大学

项目金额： 75万元

中文摘要： 由于植物根系分泌作用的存在，使根际成为土壤中生命活动最活跃的区域，在污染土壤植物修复中发挥着极为重要的作用。目前，有关超积累植物根系分泌物与根际微生物相互作用的研究报道很少，很多现象和问题还不能从机理上进行阐明。本项目从超积累植物根际微生态效应入手，以镉超积累、铅富集植物东南景天为材料，综合应用RNA-SIP、T-RFLP 、PCR-DGGE、同步辐射、稳定同位素示踪、HPLC-MS、ICP-MS等技术，系统研究东南景天根际微生物群落组成和多样性特征，追踪根系分泌物被根际微生物利用的过程，分析东南景天根际微生物对根系分泌物组成和含量的影响，阐明东南景天根系分泌物与根际微生物相互作用的机制；研究根系分泌物与根际微生物交互作用对根际铅、镉形态转化与吸收的影响，分析二者对土壤铅镉活化、吸收的贡献。为揭示植物重金属超积累机理，提高重金属污染土壤植物修复效率、保障土壤生态系统健康提供科学依据。

中文关键词： 超积累植物；微生物；分泌物；重金属；东南景天

英文摘要： The rhizosphere, the region of soil surrounding a plant root, is the site of highest microbial biomass and activity influenced by compounds exuded by the root. The interactions between root exudates and microorganisms in the rhizosphere of hyperaccumulator have not been studied extensively, major questions remain unanswered because of a reliance on cultivation-based techniques and an inability to determine the origin and fate of mediating organic compounds. Sedum alfredii (Crassulaceae), a species native to China, has been characterized as a Zn/Cd cohyperaccumulator and Pb accumulator. To date, studies on the mechanism of metal tolerance and hyperaccumulation of S. alfredii were mainly focused on the uptake and subcellular distribution characteristics, while no information is available about the interactions between root exudates and microorganisms in the rhizosphere of this plant. In this project, taking into account of the problems in the research of microecology in the rhizosphere of hyperaccumulator, both hydroponic, rhizobox and simulated experiments, as well as new techniques like RNA-SIP, T-RFLP, PCR-DGGE, synchrotron radiation techniques, stable isotope tracing, HPLC-MS and ICP-MS were used to (1) investigate the microorganisms communities and diversity trait in the rhizosphere of S. alfredii and trackin

英文关键词： hyperaccumulator；microorganisms；root exudate；heavy metal；S. alfredii