Linked Life Data

18798873

Source:http://linkedlifedata.com/resource/pubmed/id/18798873

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-1-14
pubmed:abstractText
Nitrate, the major nitrogen source for most plants, is not only a nutrient but also a signaling molecule. For almost two decades, it has been known that nitrate can rapidly induce transcriptional expression of several nitrate-related genes, a process that is referred to as the primary nitrate response. However, little is known about how plants actually sense nitrate and how the signal is transmitted in this pathway. In this study, a calcineurin B-like (CBL) -interacting protein kinase (CIPK) gene, CIPK8, was found to be involved in early nitrate signaling. CIPK8 expression was rapidly induced by nitrate. Analysis of two independent knockout mutants and a complemented line showed that CIPK8 positively regulates the nitrate-induced expression of primary nitrate response genes, including nitrate transporter genes and genes required for assimilation. Kinetic analysis of nitrate induction levels of these genes in wild-type plants indicated that there are two response phases: a high-affinity phase with a K(m) of approximately 30 mum and a low-affinity phase with a K(m) of approximately 0.9 mm. As cipk8 mutants were defective mainly in the low-affinity response, the high-affinity and low-affinity nitrate signaling systems are proposed to be genetically distinct, with CIPK8 involved in the low-affinity system. In addition, CIPK8 was found to be involved in long-term nitrate-modulated primary root growth and nitrate-modulated expression of a vacuolar malate transporter. Taken together, our results indicate that CBL-CIPK networks are responsible not only for stress responses and potassium shortage, but also for nitrate sensing.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1365-313X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
264-78
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
AtCIPK8, a CBL-interacting protein kinase, regulates the low-affinity phase of the primary nitrate response.
pubmed:affiliation
Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't