Linked Life Data

12244439

Source:http://linkedlifedata.com/resource/pubmed/id/12244439

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-9-23
pubmed:abstractText
Mutations in a component of phytochrome A (phyA)-specific light signal transduction, SPA1, result in enhanced responsiveness of Arabidopsis seedlings to red and far-red light. Here, we have examined the effects of spa1 mutations on the two known modes of phyA function, the high-irradiance responses (HIRs) to continuous irradiation with far-red light and the very-low-fluence responses (VLFRs) to inductive pulses of light that establish only a small proportion of active phyA. spa1 mutants exhibited an enhanced VLFR under hourly pulses of far-red light for hypocotyl growth inhibition, cotyledon unfolding, anthocyanin accumulation, block of greening in subsequent white light and negative regulation of phyB signaling. We provide evidence that the phenotype of spa1 mutants in red light is also caused by an increase in the VLFR. Taken together, our results indicate that light-induced hypocotyl growth inhibition in spa1 mutants is primarily due to a VLFR. While wild-type seedlings required hourly pulses of far-red light to induce a VLFR, infrequent irradiation with far-red pulses (every 12 h) was sufficient to induce a strong VLFR of hypocotyl elongation in spa1 mutants. This shows that the effect of the VLFR was more persistent in spa1 mutants than in the wild type. We, therefore, propose that SPA1 has an important function in reducing the persistence of phyA signaling. spa1 mutations also enhanced the HIRs of anthocyanin accumulation and of phyA-mediated responsivity amplification towards phyB. Thus, our results suggest that spa1 mutations amplify both the phyA-mediated VLFR and the HIR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
215
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
745-53
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
SPA1, a component of phytochrome A signal transduction, regulates the light signaling current.
pubmed:affiliation
Department of Plant Developmental and Molecular Biology, University of Düsseldorf, Geb. 26.03.02, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't