ORIGINAL ARTICLE Cell Research (2007): 411-421 CIPK9: a calcium sensor-interacting protein kinase required for low-potassium tolerance in ArabidopsisGirdhar K Pandey1, Yong Hwa Cheong1,2, Beom-Gi Kim1,3, John J Grant1, Legong Li1 and Sheng Luan1 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA2Present address: Department of Bio-Environmental Science, Sunchon National University, Suncheon, Jeonnam 540-742, Korea 3Present address: Department of molecular physiology and Biochemistry, National Institute of Agricultural Biotechnology, Suwon 441-707, Korea
Potassium is one of the major macro-nutrients essential for a number of cellular processes in plants. Low potassium level in the soil represents a limiting factor for crop production. Recent studies have identified potassium transporters that are involved in potassium acquisition, and some of them are critical for potassium nutrition under low potassium conditions. However, little is understood on the molecular components involved in low potassium signaling and responses. We report here the identification of a calcineurin B-like protein-interacting protein kinase (CIPK9) as a critical regulator of low potassium response in Arabidopsis. The CIPK9 gene was responsive to abiotic stress conditions, and its transcript was inducible in both roots and shoots by potassium deprivation. Disruption of CIPK9 function rendered the mutant plants hypersensitive to low potassium media. Further analysis indicated that K+ uptake and content were not affected in the mutant plants, implying CIPK9 in the regulation of potassium utilization or sensing processes. Cell Research (2007) 17: 411–421. doi: 10.1038/cr.2007.39; published online 8 May 2007 Keywords: calcium, calcineurin-B like protein, protein kinase, potassium nutrition, signal transduction |
copyright©2006 Institute of Biochemistry and Cell Biology,SIBS,CAS
ISSN:1001-0602(Print),1748-7838(Online);CN:31-1568
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