The ABC transporter AtPDR8 is a cadmium extrusion pump conferring heavy metal resistance
Top Cited Papers
Open Access
- 21 March 2007
- journal article
- Published by Wiley in The Plant Journal
- Vol. 50 (2), 207-218
- https://doi.org/10.1111/j.1365-313x.2007.03044.x
Abstract
Cadmium (Cd) and lead (Pb) are widespread pollutants that are toxic to plant growth. The expression of AtPDR8 was upregulated in cadmium- or lead-treated Arabidopsis thaliana. To test whether AtPDR8 is involved in heavy metal resistance, we examined transgenic Arabidopsis that over-expressed AtPDR8 and RNAi plants that exhibited a severely reduced AtPDR8 transcript level, as well as T-DNA insertion mutants of this ABC transporter. AtPDR8-over-expressing plants were more resistant to Cd2+ or Pb2+ than the wild-type and had lower Cd contents. In contrast, AtPDR8 RNAi transgenic plants and T-DNA insertion lines were more sensitive to Cd2+ or Pb2+ compared to wild-type plants and had higher Cd contents. The GFP–AtPDR8 protein was targeted to the plasma membrane, and GUS activity was present in most cells but strongest in the root hair and epidermal cells. Cd extrusion was higher in the AtPDR8-over-expressing plants in a flux assay using isolated protoplasts and radioactive 109Cd, and was lower in the RNAi transgenic plants than in the wild-type. Together, these data strongly support a role for AtPDR8 as an efflux pump of Cd2+ or Cd conjugates at the plasma membrane of Arabidopsis cells. As AtPDR8 has been suggested to be involved in the pathogen response and in the transport of chemicals that mediate pathogen resistance, this ABC protein is likely to transport a very broad range of substrates.Keywords
This publication has 61 references indexed in Scilit:
- Loss of AtPDR8, a Plasma Membrane ABC Transporter of Arabidopsis thaliana, Causes Hypersensitive Cell Death Upon Pathogen InfectionPlant and Cell Physiology, 2006
- Yeast ABC transporters – A tale of sex, stress, drugs and agingFEBS Letters, 2005
- The plant P1B‐type ATPase AtHMA4 transports Zn and Cd and plays a role in detoxification of transition metals supplied at elevated levelsFEBS Letters, 2004
- Plant Cuticular Lipid Export Requires an ABC TransporterScience, 2004
- Inventory and Comparative Analysis of Rice and Arabidopsis ATP-binding Cassette (ABC) SystemsJournal of Molecular Biology, 2004
- PHYTOCHELATINS AND METALLOTHIONEINS: Roles in Heavy Metal Detoxification and HomeostasisAnnual Review of Plant Biology, 2002
- The Paradox of Lead Poisoning PreventionScience, 1998
- ABC Transporters: From Microorganisms to ManAnnual Review of Cell Biology, 1992
- Demonstration That CFTR Is a Chloride Channel by Alteration of Its Anion SelectivityScience, 1991
- A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue CulturesPhysiologia Plantarum, 1962