The regulation of circadian period by phototransduction pathways in Arabidopsis.
Transgenic Arabidopsis plants expressing a luciferase gene fused to a circadian-regulated promoter exhibited robust rhythms in bioluminescence. The cyclic luminescence has a 24.7-hour period in white light but 30- to 36-hour periods under constant darkness. Either red or blue light shortened the period of the wild type to 25 hours. A phytochrome-deficient mutation lengthened the period in continuous red light but had little effect in continuous blue light, whereas seedlings carrying mutations that activate light-dependent pathways in darkness maintained shorter periods in constant darkness. These results suggest that both phytochrome- and blue light-responsive photoreceptor pathways control the period of the circadian clock.
National Science Foundation (NSF) Center for Biological Timing, Department of Biology, University of Virginia, Charlottesville 22903.
A J
AJ
Millar
M
M
Straume
J
J
Chory
N H
NH
Chua
S A
SA
Kay
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins; D001683:Biological Clocks / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008156:Luciferases / Q000235:genetics; D049449:Luminescence; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins
D029681:Arabidopsis Proteins; C490217:CAB1 protein, Arabidopsis; D002352:Carrier Proteins; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D008156:Luciferases