OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 145/3/831    most recent pp.107.102236v1 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 (8) Citing Articles via Google Scholar Google Scholar Articles by Lee, S. Articles by An, G. Search for Related Content PubMed PubMed Citation Articles by Lee, S. Articles by An, G. Agricola Articles by Lee, S. Articles by An, G.

ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS

Rice P_1B-Type Heavy-Metal ATPase, OsHMA9, Is a Metal Efflux Protein^1,[W],[OA]

Division of Molecular and Life Science, Biotechnology Research Center, Pohang University of Science and Technology, Pohang 790–784, Korea

P_1B-type heavy-metal ATPases (HMAs) are transmembrane metal-transporting proteins that play a key role in metal homeostasis. Despite their importance, very little is known about their functions in monocot species. We report the characterization of rice (Oryza sativa) OsHMA9, a member of the P_1B-type ATPase family. Semiquantitative reverse transcription-polymerase chain reaction analyses of seedlings showed that OsHMA9 expression was induced by a high concentration of copper (Cu), zinc (Zn), and cadmium. We also determined, through promoter::-glucuronidase analysis, that the main expression was in the vascular bundles and anthers. The OsHMA9:green fluorescence protein fusion was localized to the plasma membrane. Heterologous expression of OsHMA9 partially rescued the Cu sensitivity of the Escherichia coli copA mutant, which is defective in Cu-transporting ATPases. It did not rescue the Zn sensitivity of the zntA mutant, which is defective in Zn-transporting ATPase. To further elucidate the functional roles of OsHMA9, we isolated two independent null alleles, oshma9-1 and oshma9-2, from the T-DNA insertion population. Mutant plants exhibited the phenotype of increased sensitivity to elevated levels of Cu, Zn, and lead. These results support a role for OsHMA9 in Cu, Zn, and lead efflux from the cells. This article is the first report on the functional characterization of a P_1B-type metal efflux transporter in monocots.

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: Gynheung An (genean{at}postech.ac.kr).

^[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.107.102236

^* Corresponding author; e-mail genean{at}postech.ac.kr.

Received May 10, 2007; accepted August 31, 2007; published September 7, 2007.

This article has been cited by other articles:

				E. Sudo, M. Itouga, K. Yoshida-Hatanaka, Y. Ono, and H. Sakakibara Gene expression and sensitivity in response to copper stress in rice leaves J. Exp. Bot., September 1, 2008; 59(12): 3465 - 3474. [Abstract] [Full Text] [PDF]

				Y.-Y. Kim, D.-Y. Kim, D. Shim, W.-Y. Song, J. Lee, J. I. Schroeder, S. Kim, N. Moran, and Y. Lee Expression of the Novel Wheat Gene TM20 Confers Enhanced Cadmium Tolerance to Bakers' Yeast J. Biol. Chem., June 6, 2008; 283(23): 15893 - 15902. [Abstract] [Full Text] [PDF]