Phytochromes and cryptochromes in the entrainment of the Arabidopsis circadian clock.

@article{Somers1998PhytochromesAC,
  title={Phytochromes and cryptochromes in the entrainment of the Arabidopsis circadian clock.},
  author={David E. Somers and Paul F. Devlin and Steve A. Kay},
  journal={Science},
  year={1998},
  volume={282 5393},
  pages={
          1488-90
        }
}
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… Expand
Measuring Phytochrome-Dependent Light Input to the Plant Circadian Clock.
TLDR
The methods presented here use two automated methods of luciferase imaging in Arabidopsis to allow for high-throughput measurement of circadian clock components under a range of different light conditions. Expand
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TLDR
Observations indicate that the plant circadian clock controls the expression of these photoreceptors, revealing the formation of a new regulatory loop that could modulate gating and resetting of the circadian clock. Expand
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TLDR
Data suggest that photoreceptor gene expression patterns may be significant in the daily regulation of plant physiology and indicate an unexpectedly intimate relationship between the components of the input pathway and the putative circadian clock mechanism in higher plants. Expand
Cryptochromes and the Circadian Clock: The Story of a Very Complex Relationship in a Spinning World
TLDR
The molecular mechanisms by which plant cryptochromes control the synchronisation of the clock with the environmental light are reviewed and the circadian clock-mediated changes in cell cycle regulation and chromatin organisation are summarized. Expand
A Constitutively Active Allele of Phytochrome B Maintains Circadian Robustness in the Absence of Light1[OPEN]
TLDR
It is found that the YHB mutation is sufficient to phenocopy red light input into the circadian mechanism and to sustain robust rhythms in steady-state mRNA levels even in plants grown without light or exogenous sugars. Expand
Cryptochromes Enabling Plants and Animals to Determine Circadian Time
Cryptochromes are flavin-containing blue light photoreceptors related to photolyases-they are found in both plants and animals and have recently been described for bacteria. In plants, cryptochromesExpand
Cryptochromes--bringing the blues to circadian rhythms.
TLDR
Evidence has emerged pointing to a common role for cryptochromes in all of these organisms in entraining the circadian clock, a biochemical timing mechanism running within cells, synchronizing metabolism to the daily light-dark cycle and having consequences on a much larger scale in the regulation of behaviour such as the sleep-wake cycle. Expand
Cryptochromes integrate green light signals into the circadian system
TLDR
It is shown that low fluence rates of green light are sufficient to entrain and maintain circadian rhythms in Arabidopsis and that cryptochromes contribute to this response, and a distinct signalling mechanism enables entrainment of the circadian system in green light‐enriched environments, such as those found in undergrowth and in densely planted monoculture. Expand
Cryptochromes Are Required for Phytochrome Signaling to the Circadian Clock but Not for Rhythmicity
TLDR
It is demonstrated that the phytochromes phyA, phyB, phYD, and phyE act as photoreceptors in red light input to the clock and thatphyA and the cryptochromes cry1 and cry2 act asPhotoreceptor in blue light input, indicating that cryptochrome do not form a part of the central circadian oscillator in plants as they do in mammals. Expand
A Suite of Photoreceptors Entrains the Plant Circadian Clock
  • A. Millar
  • Medicine, Biology
  • Journal of biological rhythms
  • 2003
TLDR
This review concentrates on the resulting patterns of entrainment and on the multiple proposed mechanisms of light input to the circadian oscillator components. Expand
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