镉超积累植物及植物镉积累特性转基因改良研究进展

植物提取修复技术是一项既经济又环保的土壤镉(Cd)污染修复技术,该技术的关键是筛选Cd超积累植物或利用基因工程手段改良植物以提高其Cd积累能力。人们已发现遏兰菜等7种Cd超积累植物及美人蕉等潜在的Cd超积累植物。还发现了许多与Cd耐受和积累能力有关的基因:(1)编码与Cd积累、耐受有关酶的基因,如细菌中的ACC(1-aminocyclopropane-1-carboxylic acid),植物中的PCS(Phytochelatin Synthase)基因;(2)编码金属结合蛋白的基因:MT(Metallothionein)、转运蛋白(P-type ATPase、ABC型转运器)基因;(3)其它相关基因:Hvhsp17、PvSR2(Phaseolus vulgaris stress-related gene number 2)等。并将其中的一些基因转入到其它生物中,提高了其对Cd的耐受性和积累量,为实现Cd污染土壤修复的目标奠定基础。

Advances on screening of Cd-hyperaccumulators and transgenic improvement of plant in Cd-accumulation

Phytoextraction is an economic and environment-protected remediation technique of Cd-contaminated soils. The key is to screen Cd-hyperaccumulators or enhance the ability of Cd-accumulation by genetic engineering.Seven Cd-hyperaccumulators and some potential Cd-hyperaccumulators have been discovered.In addition,genes related with Cd accumulation in different organisms were studied.These genes included:(1)genes encoding Cd accumulation related enzymes,such as ACC of bacterial,PC synthase of plants;(2)genes encoding metal-chelatin,such as MT(Metallothionein), transport protein;(3)other genes,such as Hvhsp17,PvSR2(Phaseolus vulgaris stress-related gene number2). Some of these genes have been transformed to plants and microorganisms to enhance their cadmium tolerance and accumulation,which provides a new way for realizing the aim of remediation of Cd-contaminated soils.