This Article Full Text Full Text (PDF) A correction has been published All Versions of this Article: 15/12/2940    most recent tpc.015248v1 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 (30) Citing Articles via Google Scholar Google Scholar Articles by Catalá, R. Articles by Salinas, J. Search for Related Content PubMed PubMed Citation Articles by Catalá, R. Articles by Salinas, J. Agricola Articles by Catalá, R. Articles by Salinas, J.

Mutations in the Ca²⁺/H⁺ Transporter CAX1 Increase CBF/DREB1 Expression and the Cold-Acclimation Response in Arabidopsis

^a Departamento de Biotecnología, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria, 28040 Madrid, Spain
^b Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037

³ To whom correspondence should be addressed. E-mail salinas{at}inia.es; fax 34-91-357-3107

Transient increases in cytosolic free calcium concentration ([Ca²⁺]_cyt) are essential for plant responses to a variety of environmental stimuli, including low temperature. Subsequent reestablishment of [Ca²⁺]_cyt to resting levels by Ca²⁺ pumps and C-REPEAT BINDING FACTOR/DEHYDRATION RESPONSIVE ELEMENT BINDING FACTOR 1 (Ca²⁺/H⁺) antiporters is required for the correct transduction of the signal. We have isolated a cDNA from Arabidopsis that corresponds to a new cold-inducible gene, RARE COLD INDUCIBLE4 (RCI4), which was identical to CALCIUM EXCHANGER 1 (CAX1), a gene that encodes a vacuolar Ca²⁺/H⁺ antiporter involved in the regulation of intracellular Ca²⁺ levels. The expression of CAX1 was induced in response to low temperature through an abscisic acid–independent pathway. To determine the function of CAX1 in Arabidopsis stress tolerance, we identified two T-DNA insertion mutants, cax1-3 and cax1-4, that display reduced tonoplast Ca²⁺/H⁺ antiport activity. The mutants showed no significant differences with respect to the wild type when analyzed for dehydration, high-salt, chilling, or constitutive freezing tolerance. However, they exhibited increased freezing tolerance after cold acclimation, demonstrating that CAX1 plays an important role in this adaptive response. This phenotype correlates with the enhanced expression of CBF/DREB1 genes and their corresponding targets in response to low temperature. Our results indicate that CAX1 ensures the accurate development of the cold-acclimation response in Arabidopsis by controlling the induction of CBF/DREB1 and downstream genes.

This article has been cited by other articles:

				S. Kidokoro, K. Maruyama, K. Nakashima, Y. Imura, Y. Narusaka, Z. K. Shinwari, Y. Osakabe, Y. Fujita, J. Mizoi, K. Shinozaki, et al. The Phytochrome-Interacting Factor PIF7 Negatively Regulates DREB1 Expression under Circadian Control in Arabidopsis Plant Physiology, December 1, 2009; 151(4): 2046 - 2057. [Abstract] [Full Text] [PDF]

				W.-Y. Lin, S.-I Lin, and T.-J. Chiou Molecular regulators of phosphate homeostasis in plants J. Exp. Bot., April 1, 2009; 60(5): 1427 - 1438. [Abstract] [Full Text] [PDF]

				J. Zhao, T. Shigaki, H. Mei, Y.-q. Guo, N.-H. Cheng, and K. D. Hirschi Interaction between Arabidopsis Ca2+/H+ Exchangers CAX1 and CAX3 J. Biol. Chem., February 13, 2009; 284(7): 4605 - 4615. [Abstract] [Full Text] [PDF]

				C.-H. Dong, B. K. Zolman, B. Bartel, B.-h. Lee, B. Stevenson, M. Agarwal, and J.-K. Zhu Disruption of Arabidopsis CHY1 Reveals an Important Role of Metabolic Status in Plant Cold Stress Signaling Mol Plant, January 1, 2009; 2(1): 59 - 72. [Abstract] [Full Text] [PDF]

				E. Qudeimat, A. M. C. Faltusz, G. Wheeler, D. Lang, C. Brownlee, R. Reski, and W. Frank A PIIB-type Ca2+-ATPase is essential for stress adaptation in Physcomitrella patens PNAS, December 9, 2008; 105(49): 19555 - 19560. [Abstract] [Full Text] [PDF]

				E. Martinoia, M. Maeshima, and H. E. Neuhaus Vacuolar transporters and their essential role in plant metabolism J. Exp. Bot., January 1, 2007; 58(1): 83 - 102. [Abstract] [Full Text] [PDF]

				A. Endler, S. Meyer, S. Schelbert, T. Schneider, W. Weschke, S. W. Peters, F. Keller, S. Baginsky, E. Martinoia, and U. G. Schmidt Identification of a Vacuolar Sucrose Transporter in Barley and Arabidopsis Mesophyll Cells by a Tonoplast Proteomic Approach Plant Physiology, May 1, 2006; 141(1): 196 - 207. [Abstract] [Full Text] [PDF]

				T. Kamiya, T. Akahori, M. Ashikari, and M. Maeshima Expression of the Vacuolar Ca2+/H+ Exchanger, OsCAX1a, in Rice: Cell and Age Specificity of Expression, and Enhancement by Ca2+ Plant Cell Physiol., January 1, 2006; 47(1): 96 - 106. [Abstract] [Full Text] [PDF]

				T. Kamiya, T. Akahori, and M. Maeshima Expression Profile of the Genes for Rice Cation/H+ Exchanger Family and Functional Analysis in Yeast Plant Cell Physiol., October 1, 2005; 46(10): 1735 - 1740. [Abstract] [Full Text] [PDF]

				N.-H. Cheng, J. K. Pittman, T. Shigaki, J. Lachmansingh, S. LeClere, B. Lahner, D. E. Salt, and K. D. Hirschi Functional Association of Arabidopsis CAX1 and CAX3 Is Required for Normal Growth and Ion Homeostasis Plant Physiology, August 1, 2005; 138(4): 2048 - 2060. [Abstract] [Full Text] [PDF]