RT Journal Article SR Electronic T1 The regulation of circadian period by phototransduction pathways in Arabidopsis JF Science JO Science FD American Association for the Advancement of Science SP 1163 OP 1166 DO 10.1126/science.7855596 VO 267 IS 5201 A1 Millar, AJ A1 Straume, M A1 Chory, J A1 Chua, NH A1 Kay, SA YR 1995 UL http://science.sciencemag.org/content/267/5201/1163.abstract AB 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.