OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 143/4/1705    most recent pp.106.092015v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (18) Citing Articles via Google Scholar Google Scholar Articles by Haydon, M. J. Articles by Cobbett, C. S. Search for Related Content PubMed PubMed Citation Articles by Haydon, M. J. Articles by Cobbett, C. S. Agricola Articles by Haydon, M. J. Articles by Cobbett, C. S.

ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS

A Novel Major Facilitator Superfamily Protein at the Tonoplast Influences Zinc Tolerance and Accumulation in Arabidopsis^{1,[C],[W],[OA]}

Department of Genetics, University of Melbourne, Parkville, Victoria 3010, Australia

Zinc (Zn) is an essential micronutrient required by all cells but is toxic in excess. We have identified three allelic Zn-sensitive mutants of Arabidopsis (Arabidopsis thaliana). The gene, designated ZINC-INDUCED FACILITATOR1 (ZIF1), encodes a member of the major facilitator superfamily of membrane proteins, which are found in all organisms and transport a wide range of small, organic molecules. Shoots of zif1 mutants showed increased accumulation of Zn but not other metal ions. In combination with mutations affecting shoot-to-root Zn translocation, zif1 hma2 hma4 triple mutants accumulated less Zn than the wild type but remained Zn sensitive, suggesting that the zif1 Zn-sensitive phenotype is due to altered Zn distribution. zif1 mutants were also more sensitive to cadmium but less sensitive to nickel. ZIF1 promoter--glucuronidase fusions were expressed throughout the plant, with strongest expression in young tissues, and predominantly in the vasculature in older tissues. ZIF1 expression was highly induced by Zn and, to a lesser extent, by manganese. A ZIF1-green fluorescent protein fusion protein localized to the tonoplast in transgenic plants. MTP1 has been identified as a tonoplast Zn transporter and a zif1-1 mtp1-1 double mutant was more sensitive to Zn than either of the single mutants, suggesting ZIF1 influences a distinct mechanism of Zn homeostasis. Overexpression of ZIF1 conferred increased Zn tolerance and interveinal leaf chlorosis in some transgenic lines in which ZIF1 expression was high. We propose that ZIF1 is involved in a novel mechanism of Zn sequestration, possibly by transport of a Zn ligand or a Zn ligand complex into vacuoles.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Chris Cobbett (ccobbett{at}unimelb.edu.au).

^[C] Some figures in this article are displayed in color online but in black and white in the print edition.

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.106.092015

^* Corresponding author, e-mail ccobbett{at}unimelb.edu.au; fax 61–3–8344–5138.

Received October 26, 2006; accepted January 28, 2007; published February 2, 2007.

This article has been cited by other articles:

				M. Kawachi, Y. Kobae, H. Mori, R. Tomioka, Y. Lee, and M. Maeshima A Mutant Strain Arabidopsis thaliana that Lacks Vacuolar Membrane Zinc Transporter MTP1 Revealed the Latent Tolerance to Excessive Zinc Plant Cell Physiol., June 1, 2009; 50(6): 1156 - 1170. [Abstract] [Full Text] [PDF]

				B. Tauris, S. Borg, P. L. Gregersen, and P. B. Holm A roadmap for zinc trafficking in the developing barley grain based on laser capture microdissection and gene expression profiling J. Exp. Bot., March 1, 2009; 60(4): 1333 - 1347. [Abstract] [Full Text] [PDF]

				M. Morel, J. Crouzet, A. Gravot, P. Auroy, N. Leonhardt, A. Vavasseur, and P. Richaud AtHMA3, a P1B-ATPase Allowing Cd/Zn/Co/Pb Vacuolar Storage in Arabidopsis Plant Physiology, February 1, 2009; 149(2): 894 - 904. [Abstract] [Full Text] [PDF]

				P. Tennstedt, D. Peisker, C. Bottcher, A. Trampczynska, and S. Clemens Phytochelatin Synthesis Is Essential for the Detoxification of Excess Zinc and Contributes Significantly to the Accumulation of Zinc Plant Physiology, February 1, 2009; 149(2): 938 - 948. [Abstract] [Full Text] [PDF]

				M. Kuramata, S. Masuya, Y. Takahashi, E. Kitagawa, C. Inoue, S. Ishikawa, S. Youssefian, and T. Kusano Novel Cysteine-Rich Peptides from Digitaria ciliaris and Oryza sativa Enhance Tolerance to Cadmium by Limiting its Cellular Accumulation Plant Cell Physiol., January 1, 2009; 50(1): 106 - 117. [Abstract] [Full Text] [PDF]