Linked Life Data

17662034

Source:http://linkedlifedata.com/resource/pubmed/id/17662034

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-9-12
pubmed:abstractText
Most organisms have evolved a timing mechanism or circadian clock that is able to generate 24 h rhythmic oscillations in multiple biological events. The environmental fluctuations in light and temperature synchronize the expression and activity of key oscillator components that ultimately define the period, phase and amplitude of output rhythms. In Arabidopsis, overexpression of the casein kinase 2 (CK2) regulatory subunits, CKB3 or CKB4, alters the function of the clock under free-running conditions, and results in period-shortening of genes peaking at different phase angles. Here, we examine the effects of CKB4 overexpression (CKB4-ox) on a number of clock outputs that are modulated by day length or photoperiod. We have found a phase shift in gene expression, shortening of hypocotyl elongation and earlier than wild-type initiation of flowering under short-day conditions. Our study shows that the earlier expression phases of the floral induction genes GIGANTEA, FLAVIN-BINDING KELCH REPEAT F-BOX1 and CONSTANS correlate with higher abundance of the FLOWERING LOCUS T transcript under short-day conditions. Matching the period of the external light/dark cycles relative to the endogenous short period of the CKB4-ox oscillator restores the phase of gene expression and the flowering sensitivity to day length, indicating that a clock defect is responsible for the CKB4-ox phenotypes. Our studies suggest a function for CKB4 very close to the oscillator, as expression of the core components TIMING OF CAB EXPRESSION 1 and CIRCADIAN CLOCK ASSOCIATED 1 is also altered in CKB4-ox plants. Based on our results, we propose that oscillator dysfunction is responsible for the period defect of CKB4-ox plants that leads to clock dissonance with the environment and reduced sensitivity to day length.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Arabidopsis Proteins, http://linkedlifedata.com/resource/pubmed/chemical/CAB2 protein, Arabidopsis, http://linkedlifedata.com/resource/pubmed/chemical/CCA1 protein, Arabidopsis, http://linkedlifedata.com/resource/pubmed/chemical/CKB4 protein, Arabidopsis, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Casein Kinase II, http://linkedlifedata.com/resource/pubmed/chemical/Light-Harvesting Protein Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Luciferases, http://linkedlifedata.com/resource/pubmed/chemical/Protein Subunits, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/TOC1 protein, Arabidopsis, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
966-77
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Altered oscillator function affects clock resonance and is responsible for the reduced day-length sensitivity of CKB4 overexpressing plants.
pubmed:affiliation
Consorcio CSIC-IRTA, Laboratorio de Genética Molecular Vegetal, Instituto de Biología Molecular de Barcelona (IBMB-CSIC), C/Jordi Girona 18-26, 08034 Barcelona, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't