Molecular Mechanism of Nickel Hyperaccumulation in Thlaspi goesingense

在过去的150年里，密集的工业和农业活动给环境带来了沉重的重金属负担。植物萃取，即利用植物从土壤中清除污染物，包括有毒金属在内的环境污染物，有可能使这些受污染地点的经济恢复成为可能。为了使植物提取成为现有土壤修复策略的可行替代方案，将需要存在高生物量，快速生长的金属积累植物。不幸的是，目前还不存在具有所有这些理想特性的植物。然而，有有限数量的植物，统称为超积累植物，生长在自然富含锌、镍和硒等各种金属的土壤上。这些植物有能力自然积累这些金属，达到其茎干重的0.1%至3%；这比大多数其他植物高出至少1000倍。这种独特的能力使这些植物成为开发植物提取作物的理想起点。开发这类作物的一种方法是鉴定这些高富集植物中负责金属积累的基因。一旦这些基因被鉴定和完全鉴定，就可以转移到高生物量、快速生长的植物中，从而产生非常适合植物修复的作物。这笔拨款将资助从镍超富集菌Thlaspi goesingense中鉴定这种“金属超富集”基因。一旦确定，这些基因对植物修复的有用性将通过将其转移到拟南芥（一种方便的模式植物）来快速评估。在这种模式植物中鉴定出的增强金属耐受性和积累的基因将被选择转移到更适合植物修复应用的植物上。

Intensive industrial and agricultural activity over the last 150 years has imposed a large burden of heavy metals on the environment. Phytoextraction, the use of plants for environmental cleanup of pollutants, including toxic metals, from soils, holds the potential to allow the economic restoration of these contaminated sites. For phytoextraction to be a viable alternative to existing soil remediation strategies it will require the existence of high biomass, rapidly growing metal-accumulating plants. Unfortunately, plants do not exist at present that have all these desirable characteristics. There are, however, a limited numbers of plants, collectively termed hyperaccumulators, that grow on soils naturally enriched in various metals including Zn, Ni and Se. These plants have the ability to naturally accumulate these metals to between 0.1 and 3% of their shoot dry weight; this is at least 1000-fold higher than most other plants. This unique ability makes these plants an ideal starting point for the development of phytoextraction crops. One way to develop such crops is to identify the genes responsible for metal accumulation in these hyperaccumulator plants. Once identified and fully characterized these genes could be transferred into high biomass, rapidly-growing plants to generate crops ideally suited for phytoremediation. This grant will fund the identification of such "metal hyperaccumulation" genes from the nickel hyperaccumulator Thlaspi goesingense. Once identified, the usefulness of these genes for phytoremediation will be rapidly assessed by their transfer to Arabidopsis thaliana, a convenient model plant. Genes identified for enhanced metal tolerance and accumulation in this model plant will then be selected for transfer to plants more suited to phytoremediation applications.