This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/2/485    most recent tpc.106.048538v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Plant Cell Similar articles in this journal Similar articles in ISI 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 ISI Web of Science (20) Citing Articles via Google Scholar Google Scholar Articles by Fujii, H. Articles by Zhu, J.-K. Search for Related Content PubMed PubMed Citation Articles by Fujii, H. Articles by Zhu, J.-K. Agricola Articles by Fujii, H. Articles by Zhu, J.-K.

Identification of Two Protein Kinases Required for Abscisic Acid Regulation of Seed Germination, Root Growth, and Gene Expression in Arabidopsis^[W]

Center for Plant Cell Biology, Institute for Integrative Genome Biology and Department of Botany and Plant Sciences, University of California, Riverside, California 92521

¹ To whom correspondence should be addressed. E-mail jian-kang.zhu{at}ucr.edu; fax 951-827-7115.

Abscisic acid (ABA) is an important phytohormone regulating various plant processes, including seed germination. Although phosphorylation has been suggested to be important, the protein kinases required for ABA signaling during seed germination and seedling growth remain elusive. Here, we show that two protein kinases, SNF1-RELATED PROTEIN KINASE2.2 (SnRK2.2) and SnRK2.3, control responses to ABA in seed germination, dormancy, and seedling growth in Arabidopsis thaliana. A snrk2.2 snrk2.3 double mutant, but not snrk2.2 or snrk2.3 single mutants, showed strong ABA-insensitive phenotypes in seed germination and root growth inhibition. Changes in seed dormancy and ABA-induced Pro accumulation consistent with ABA insensitivity were also observed. The snrk2.2 snrk2.3 double mutant had a greatly reduced level of a 42-kD kinase activity capable of phosphorylating peptides from ABF (for ABA Response Element Binding Factor) transcription factors. ABA-induced expression of several genes whose promoters contain an ABA response element (ABRE) was reduced in snrk2.2 snrk2.3, suggesting that the mechanism of SnRK2.2 and SnRK2.3 action in ABA signaling involves the activation of ABRE-driven gene expression through the phosphorylation of ABFs. Together, these results demonstrate that SnRK2.2 and SnRK2.3 are redundant but key protein kinases that mediate a major part of ABA signaling in Arabidopsis.

Related articles in Plant Cell:

Two Protein Kinases Required for ABA Signaling in Arabidopsis

Nancy A. Eckardt
Plant Cell 2007 19: 394a. [Full Text]  

This article has been cited by other articles:

				S. Rubio, A. Rodrigues, A. Saez, M. B. Dizon, A. Galle, T.-H. Kim, J. Santiago, J. Flexas, J. I. Schroeder, and P. L. Rodriguez Triple Loss of Function of Protein Phosphatases Type 2C Leads to Partial Constitutive Response to Endogenous Abscisic Acid Plant Physiology, July 1, 2009; 150(3): 1345 - 1355. [Abstract] [Full Text] [PDF]

				S.-Y. Park, P. Fung, N. Nishimura, D. R. Jensen, H. Fujii, Y. Zhao, S. Lumba, J. Santiago, A. Rodrigues, T.-f. F. Chow, et al. Abscisic Acid Inhibits Type 2C Protein Phosphatases via the PYR/PYL Family of START Proteins Science, May 22, 2009; 324(5930): 1068 - 1071. [Abstract] [Full Text] [PDF]

				H. Fujii and J.-K. Zhu Arabidopsis mutant deficient in 3 abscisic acid-activated protein kinases reveals critical roles in growth, reproduction, and stress PNAS, May 19, 2009; 106(20): 8380 - 8385. [Abstract] [Full Text] [PDF]

				K. Miura, J. Lee, J. B. Jin, C. Y. Yoo, T. Miura, and P. M. Hasegawa Sumoylation of ABI5 by the Arabidopsis SUMO E3 ligase SIZ1 negatively regulates abscisic acid signaling PNAS, March 31, 2009; 106(13): 5418 - 5423. [Abstract] [Full Text] [PDF]

				K. Nakashima, Y. Ito, and K. Yamaguchi-Shinozaki Transcriptional Regulatory Networks in Response to Abiotic Stresses in Arabidopsis and Grasses Plant Physiology, January 1, 2009; 149(1): 88 - 95. [Full Text] [PDF]

				U. Piskurewicz, Y. Jikumaru, N. Kinoshita, E. Nambara, Y. Kamiya, and L. Lopez-Molina The Gibberellic Acid Signaling Repressor RGL2 Inhibits Arabidopsis Seed Germination by Stimulating Abscisic Acid Synthesis and ABI5 Activity PLANT CELL, October 1, 2008; 20(10): 2729 - 2745. [Abstract] [Full Text] [PDF]

				A. Gianinetti and P. Vernieri On the role of abscisic acid in seed dormancy of red rice J. Exp. Bot., September 26, 2007; (2007) erm198v1. [Abstract] [Full Text] [PDF]