Abstract
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.
Original language | English |
---|---|
Pages (from-to) | 1140-1145 |
Number of pages | 6 |
Journal | Nature Biotechnology |
Volume | 20 |
Issue number | 11 |
DOIs | |
Publication status | Published - Nov 2002 |
Keywords
- arabidopsis-thaliana
- saccharomyces-cerevisiae
- ABC-transporter
- drinking-water
- Indian mustard
- plasmid R773
- anion pump
- protein
- phosphate
- detoxification