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

Om Parkash Dhankher, Yujing Li, Barry P. Rosen, Jin Shi, David Salt, Julie F. Senecoff, Nupur A. Sashti, Richard B. Meagher, David Edward Salt

Research output: Contribution to journalArticle

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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 languageEnglish
Pages (from-to)1140-1145
Number of pages6
JournalNature Biotechnology
Volume20
Issue number11
DOIs
Publication statusPublished - Nov 2002

Keywords

  • arabidopsis-thaliana
  • saccharomyces-cerevisiae
  • ABC-transporter
  • drinking-water
  • Indian mustard
  • plasmid R773
  • anion pump
  • protein
  • phosphate
  • detoxification

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