US EPA

1020205 

Journal Article 

Engineering tolerance and hyperaccumulation of arsenic in plants by combining arsenate reductase and gamma-glutamylcysteine synthetase expression 

Dhankher, OP; Li, Y; Rosen, BP; Shi, J; Salt, D; Senecoff, JF; Sashti, NA; Meagher, RB 

2002 

1 

Nature Biotechnology
ISSN: 1087-0156
EISSN: 1546-1696 

20 

11 

1140-1145 

English 

12368812 

10.1038/nbt747 

WOS:000179041500026 

We have developed a genetics-based phytoremediation strategy for arsenic in which the oxyanion arsenate is transported aboveground, reduced to arsenite, and sequestered in thiol-peptide complexes. The Escherichia coli arsC gene encodes arsenate reductase (ArsC), which catalyzes the glutathione (GSH)-coupled electrochemical reduction of arsenate to the more toxic arsenite. Arabidopsis thaliana plants transformed with the arsC gene expressed from a light-induced soybean rubisco promoter (SRS1p) strongly express ArsC protein in leaves, but not roots, and were consequently hypersensitive to arsenate. Arabidopsis plants expressing the E. coli gene encoding gamma-glutamylcysteine synthetase (gamma-ECS) from a strong constitutive actin promoter (ACT2p) were moderately tolerant to arsenic compared with wild type. However, plants expressing SRS1p/ArsC and ACT2p/gamma-ECS together showed substantially greater arsenic tolerance than gamma-ECS or wild-type plants. When grown on arsenic, these plants accumulated 4- to 17-fold greater fresh shoot weight and accumulated 2- to 3-fold more arsenic per gram of tissue than wild type or plants expressing gamma-ECS or ArsC alone. This arsenic remediation strategy should be applicable to a wide variety of plant species.