Publication Date:
2008-01-25
Description:
Cell elongation during seedling development is antagonistically regulated by light and gibberellins (GAs). Light induces photomorphogenesis, leading to inhibition of hypocotyl growth, whereas GAs promote etiolated growth, characterized by increased hypocotyl elongation. The mechanism underlying this antagonistic interaction remains unclear. Here we report on the central role of the Arabidopsis thaliana nuclear transcription factor PIF4 (encoded by PHYTOCHROME INTERACTING FACTOR 4) in the positive control of genes mediating cell elongation and show that this factor is negatively regulated by the light photoreceptor phyB (ref. 4) and by DELLA proteins that have a key repressor function in GA signalling. Our results demonstrate that PIF4 is destabilized by phyB in the light and that DELLAs block PIF4 transcriptional activity by binding the DNA-recognition domain of this factor. We show that GAs abrogate such repression by promoting DELLA destabilization, and therefore cause a concomitant accumulation of free PIF4 in the nucleus. Consistent with this model, intermediate hypocotyl lengths were observed in transgenic plants over-accumulating both DELLAs and PIF4. Destabilization of this factor by phyB, together with its inactivation by DELLAs, constitutes a protein interaction framework that explains how plants integrate both light and GA signals to optimize growth and development in response to changing environments.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉de Lucas, Miguel -- Daviere, Jean-Michel -- Rodriguez-Falcon, Mariana -- Pontin, Mariela -- Iglesias-Pedraz, Juan Manuel -- Lorrain, Severine -- Fankhauser, Christian -- Blazquez, Miguel Angel -- Titarenko, Elena -- Prat, Salome -- England -- Nature. 2008 Jan 24;451(7177):480-4. doi: 10.1038/nature06520.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Departamento de Genetica Molecular de Plantas, Centro Nacional de Biotecnologia-CSIC, Campus Univ. Autonoma de Madrid, Cantoblanco. c/ Darwin 3, 28049 Madrid, Spain.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18216857" target="_blank"〉PubMed〈/a〉
Keywords:
Arabidopsis/cytology/*drug effects/metabolism/*radiation effects
;
Arabidopsis Proteins/chemistry/genetics/*metabolism
;
Basic Helix-Loop-Helix Transcription Factors/chemistry/genetics/metabolism
;
Cell Shape/*drug effects/*radiation effects
;
Cell Size/drug effects/radiation effects
;
DNA, Plant/metabolism
;
Gibberellins/*pharmacology
;
Hypocotyl/genetics/growth & development/metabolism
;
*Light
;
Nuclear Proteins/chemistry/genetics/metabolism
;
Phytochrome B/genetics/metabolism
;
Plant Leaves/metabolism
;
Protein Binding
;
Seedlings/metabolism
;
Signal Transduction/drug effects
;
Tobacco/metabolism
;
Triazoles/pharmacology
;
Two-Hybrid System Techniques
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
