Guo Jiangbo, Dai Xiaojing, Xu Wenzhong, Ma Mi
Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, 20 Nan XinCun XiangShan, Beijing 100093, PR China.
Chemosphere. 2008 Jul;72(7):1020-6. doi: 10.1016/j.chemosphere.2008.04.018. Epub 2008 May 27.
The goal of this study was to develop transgenic plants with increased tolerance for and accumulation of heavy metals and metalloids from soil by simultaneous overexpression of AsPCS1 and GSH1 (derived from garlic and baker's yeast) in Arabidopsis thaliana. Phytochelatins (PCs) and glutathione (GSH) are the main binding peptides involved in chelating heavy metal ions in plants and other living organisms. Single-gene transgenic lines had higher tolerance to and accumulated more Cd and As than wild-type. Compared to single-gene transgenic lines, dual-gene transformants exhibited significantly higher tolerance to and accumulated more Cd and As. One of the dual-gene transgenic lines, PG1, accumulated twice the amount of Cd as single-gene transgenic lines. Simultaneous overexpression of AsPCS1 and GSH1 led to elevated total PC production in transgenic Arabidopsis. These results indicate that such a stacking of modified genes is capable of increasing Cd and As tolerance and accumulation in transgenic lines, and represents a highly promising new tool for use in phytoremediation efforts.
本研究的目标是通过在拟南芥中同时过表达AsPCS1和GSH1（分别源自大蒜和面包酵母），培育出对土壤中重金属和类金属具有更高耐受性和积累能力的转基因植物。植物螯合肽（PCs）和谷胱甘肽（GSH）是植物和其他生物体中参与螯合重金属离子的主要结合肽。单基因转基因株系比野生型对镉和砷具有更高的耐受性，并且积累了更多的镉和砷。与单基因转基因株系相比，双基因转化体对镉和砷表现出显著更高的耐受性，并且积累了更多的镉和砷。其中一个双基因转基因株系PG1积累的镉量是单基因转基因株系的两倍。AsPCS1和GSH1的同时过表达导致转基因拟南芥中总PC产量升高。这些结果表明，这种修饰基因的叠加能够提高转基因株系对镉和砷的耐受性和积累能力，是植物修复中极具前景的新工具。
