Enhanced Cadmium Accumulation in Transgenic Tobacco Expressing the Phytochelatin Synthase Gene of Cynodon dactylon L  

作　　者：Jiangchuan Li Jiangbo Guo Wenzhong Xu Mi Ma 

机构地区：[1]Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China [2]Graduate School of the Chinese Academy of Sciences, Beijing 100039, China

出　　处：《Journal of Integrative Plant Biology》2006年第8期928-937,共10页植物学报（英文版）

基　　金：Supported by the Special Project of Transgenic Plants Research (JY03A2001)

摘　　要：Bermudagrass （Cynodon dactylon L. cv. Goldensun） is highly resistant to and accumulates large amounts of cadmium （Cd）. A phytochelatin synthase （PCS） cDNA （CdPCS1） was isolated from this grass by rapid amplification of cDNA ends. The putative CdPCS1 protein shared a high homology with PCS from other plants, with 79% homology at the N-terminal and 47% homology at the C-terminah However, 16 Cys residues were found at the C-terminal of CdPCS1, and among these residues, three positions were different from other PCS proteins. Semiquantitative reverse transcription-polymerase chain reaction analysis showed that Cd stress induced CdPCS1 expression in both roots and leaves in Bermudagrass. We verified that CdPCS1 plays an important role in Cd tolerance in yeast cells by expressing the gene in ABDE1, a Cdsensitive mutant. CdPCS1 was then introduced into tobacco plants. The phytochelatin level in some transgenic tobacco lines increased 3.88-fold more than in wild type plants and Cd accumulation in these transgenic plants was enhanced 3.21-fold accordingly. The results suggested that CdPCS1 could be used as a gene element for phytoremediation in the future.Bermudagrass （Cynodon dactylon L. cv. Goldensun） is highly resistant to and accumulates large amounts of cadmium （Cd）. A phytochelatin synthase （PCS） cDNA （CdPCS1） was isolated from this grass by rapid amplification of cDNA ends. The putative CdPCS1 protein shared a high homology with PCS from other plants, with 79% homology at the N-terminal and 47% homology at the C-terminah However, 16 Cys residues were found at the C-terminal of CdPCS1, and among these residues, three positions were different from other PCS proteins. Semiquantitative reverse transcription-polymerase chain reaction analysis showed that Cd stress induced CdPCS1 expression in both roots and leaves in Bermudagrass. We verified that CdPCS1 plays an important role in Cd tolerance in yeast cells by expressing the gene in ABDE1, a Cdsensitive mutant. CdPCS1 was then introduced into tobacco plants. The phytochelatin level in some transgenic tobacco lines increased 3.88-fold more than in wild type plants and Cd accumulation in these transgenic plants was enhanced 3.21-fold accordingly. The results suggested that CdPCS1 could be used as a gene element for phytoremediation in the future.

关 键 词：CADMIUM Cynodon dactylon PHYTOCHELATIN phytochelatin synthase phytoremediation. 

分 类 号：Q949[生物学—植物学]