title: Phytochromes and cryptochromes in the entrainment of the Arabidopsis circadian clock.
abstract: Circadian clocks are synchronized by environmental cues such as light. Photoreceptor-deficient Arabidopsis thaliana mutants were used to measure the effect of light fluence rate on circadian period in plants. Phytochrome B is the primary high-intensity red light photoreceptor for circadian control, and phytochrome A acts under low-intensity red light. Cryptochrome 1 and phytochrome A both act to transmit low-fluence blue light to the clock. Cryptochrome 1 mediates high-intensity blue light signals for period length control. The presence of cryptochromes in both plants and animals suggests that circadian input pathways have been conserved throughout evolution.
authors.affiliation: Department of Cell Biology and National Science Foundation Center for Biological Timing, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92307, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Somers
authors.forename: P F
authors.initials: PF
authors.lastname: Devlin
authors.forename: S A
authors.initials: SA
authors.lastname: Kay
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins; D001683:Biological Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics / Q000502:physiology*; D008027:Light; D009154:Mutation; D010786:Photoreceptor Cells; D017956:Photoreceptor Cells, Invertebrate; D010834:Phytochrome / Q000235:genetics / Q000502:physiology*; D051942:Phytochrome A; D051939:Phytochrome B; D030821:Plants, Genetically Modified; D043562:Receptors, G-Protein-Coupled; D015398:Signal Transduction; D014157:Transcription Factors
chemical_list: D029681:Arabidopsis Proteins; C538962:CRY1 protein, Arabidopsis; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; C497973:PHYA protein, Arabidopsis; C497952:PHYB protein, Arabidopsis; D051942:Phytochrome A; D043562:Receptors, G-Protein-Coupled; D014157:Transcription Factors; C119828:cry protein, Drosophila; D010834:Phytochrome; D051939:Phytochrome B