title: CIPK9: a calcium sensor-interacting protein kinase required for low-potassium tolerance in Arabidopsis.
abstract: 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.
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Girdhar K
authors.initials: GK
authors.lastname: Pandey
authors.forename: Yong Hwa
authors.initials: YH
authors.lastname: Cheong
authors.forename: Beom-Gi
authors.initials: BG
authors.lastname: Kim
authors.forename: John J
authors.initials: JJ
authors.lastname: Grant
authors.forename: Legong
authors.initials: L
authors.lastname: Li
authors.forename: Sheng
authors.initials: S
authors.lastname: Luan
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D020013:Calcium Signaling; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D009997:Osmotic Pressure; D030821:Plants, Genetically Modified; D011188:Potassium / Q000494:pharmacology / Q000502:physiology*; D011494:Protein Kinases / Q000235:genetics* / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D011494:Protein Kinases; C523347:CIPK9 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D011188:Potassium