Authors: Ksenija Gasic Schuyler S Korban
Publish Date: 2006/11/04
Volume: 225, Issue: 5, Pages: 1277-1285
Abstract
Phytochelatins PCs are heavy metal binding peptides that play an important role in sequestration and detoxification of heavy metals in plants In this study our goal was to develop transgenic plants with increased tolerance for and accumulation of heavy metals from soil by expressing an Arabidopsis thaliana AtPCS1 gene encoding phytochelatin synthase PCS in Indian mustard Brassica juncea L A 35S promoter fused to a FLAG–tagged AtPCS1 cDNA was expressed in Indian mustard and transgenic lines designated pc lines were evaluated for tolerance to and accumulation of Cd and Zn Transgenic plants with moderate AtPCS1 expression levels showed significantly higher tolerance to Cd and Zn stress but accumulated significantly less Cd and Zn than wild type plants in both shoot and root tissues However transgenic plants with highest expression of the transgene did not exhibit enhanced Cd and Zn tolerance Shoots of Cdtreated pc plants had significantly higher levels of phytochelatins and thiols than wildtype plants Significantly lower concentrations of gluthatione in Cdtreated shoot and root tissues of transgenic plants were observed Moderate expression levels of phytochelatin synthase improved the ability of Indian mustard to tolerate certain levels of heavy metals but at the same time did not increase the accumulation potential for Cd and ZnWe would like to thank Dr Norman Terry for supplying us with Indian mustard seed including transgenic line GS7 and Dr Peter Goldsbrough for helping us with PCs analyses This work was funded by a grant received from the Illinois Department of Natural Resources
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