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CLOCK CYCLE. "Accumulation of the TOC1 protein at night promotes transcription from the LHY and CCA1 promoters, thus initiating a new cycle." https://lnkd.in/d_f7kfY View in LinkedIn

FRAGMENT FROM NATURE continues for the second of three weekends on the theme of plant clocks, why they exist, and how they work. These mechanisms are ubiquitous across taxa, and are sophisticated in construction. In many (or most) cases, when external stimuli are removed, they keep ticking. Living things, it seems, are obsessed with time, and have put a lot of ingenuity into marking its passage. I shall refrain from quoting TS Eliot. View in LinkedIn

CLOCK GENES. "Expression of the LHY and CCA1 mRNA levels oscillates and levels of both transcripts peak shortly after dawn. The LHY and CCA1 proteins also are synthesized rhythmically with a lag of approximately 2 h after their cognate mRNAs. Both transcription factors bind to a promoter element known as the evening element and act to inhibit transcription of evening-specific genes, including TOC1. In the evening, the level of both repressors declines and transcription of the TOC1 gene resumes." https://lnkd.in/d_f7kfY View in LinkedIn

POSSIBILITY OF LIFE TRANSITION. "Upon observing the seemingly unlimited complexity and variety of Life's evolving patterns, it becomes almost impossible to refrain from imagining, along with Conway, that, were the game really to be played on an infinite lattice, there must surely arise true living ‘life-forms’, perhaps themselves evolving into more complex, possibly sentient, ‘organisms’." https://lnkd.in/d3B2FKW View in LinkedIn

FEEDBACK LOOPS. "The circadian oscillator of higher plants comprises transcriptional– translational feedback loops similar to those described earlier for fungal and animal clocks." https://lnkd.in/d_f7kfY View in LinkedIn

CLOCK CENTRAL. "In plants, the circadian clock controls expression of approximately 6% of the transcriptome. This includes genes encoding components of all major metabolic pathways as well as genes involved in hormone biosynthesis, photoreceptors and floral regulators such as CO, FT and GI." https://lnkd.in/d_f7kfY View in LinkedIn

CLOCK GENE CO. "These results were consistent with a model in which expression of CO under the control of the circadian clock mediates rhythmic changes in photoresponsiveness and perception of external coincidence with light." https://lnkd.in/d_f7kfY View in LinkedIn

MIND GAMES. "When Arabidopsis plants were exposed to a range of these atypical light–dark cycles, floral responses were not determined by the number of light or dark hours within a cycle but reflected how much transcription of the clock-controlled gene CO coincided with light." https://lnkd.in/d_f7kfY View in LinkedIn

ENTRAINMENT. "One of the fundamental properties of the circadian clock is that it will advance or delay its phase (that is, shift its rhythm forward or back relative to dawn and dusk) when entrained to light–dark cycles that are either longer or shorter than 24 h, respectively." https://lnkd.in/d_f7kfY View in LinkedIn

MUTANTS. "Abnormal function of the circadian clock in Arabidopsis mutants was correlated with defective floral responses to photoperiod. For example, the short-period mutant timing of cab 1-1 (toc1-1) flowered earlier than wild-type under short day conditions, whereas the long-period mutant zeitlupe (ztl) exhibited delayed flowering under long day conditions." https://lnkd.in/d_f7kfY View in LinkedIn