Month: September 2022

DARK INHIBITION. "The protein does not accumulate when expression of the CO transcript takes place in darkness and FT transcription is not induced. Accumulation of the CO protein is promoted under monochromatic far-red and blue light by the action of PHYA- and CRY2-mediated pathways, respectively, but is prevented in red light via a PHYB-dependent pathway." https://lnkd.in/d_f7kfY View in LinkedIn

RED VS BLUE LIGHT SIGNALS. "Under natural conditions of white light where all of these photoreceptors are stimulated at the same time, the balance between the activity of these different pathways must determine the floral response. This is in good agreement with mutant analyses, which suggested that far-red light acting through PHYA and blue light acting through CRY1 and CRY2 may act to antagonize the repression of flowering mediated by PHYB." https://lnkd.in/d_f7kfY View in LinkedIn

CYCLE REGULATOR. "Rhythmic transcription of CO under the control of the circadian clock provides the basis for rhythmic responsiveness to light in photoperiodism, since the effects of CRY2 and PHYA on CO protein accumulation can take place only when the CO mRNA is expressed and actively translated." https://lnkd.in/d_f7kfY View in LinkedIn

"PERCEPTION OF DAYLENGTH is mediated by an interaction of a light and a circadian rhythm. The timing mechanism of the clock is composed of multiple transcriptional–translational feedback loops, whose oscillations are entrained to diurnal light–dark cycles through the action of phytochrome and cryptochrome photoreceptors." https://lnkd.in/d_f7kfY View in LinkedIn

"LIGHT RESETS THE CLOCK through at least two mechanisms, including transcriptional induction of LHY and CCA1 expression and light-induced degradation of the TOC1 protein. Effects of light on the clock are dampened at night through the action of the rhythmically expressed protein ELF3." https://lnkd.in/d_f7kfY View in LinkedIn

"DOWNSTREAM of the clock, expression of the floral regulator CO is rhythmic under diurnal light– dark cycles. Light promotes expression of the CO mRNA at the end of a long day through the action of the rhythmically expressed photoreceptor FKF1. In addition, the circadian oscillator mediates light-independent expression of the CO mRNA at night." https://lnkd.in/d_f7kfY View in LinkedIn

FLOWERING SIGNALS. "The role of a florigenic signal has also been confirmed and although its exact nature is still unknown, there are prospects of it being discovered in the foreseeable future. We can also soon expect to understand more fully the basis for the different requirements for light quantity and quality in different species." https://lnkd.in/d_f7kfY View in LinkedIn

LEAF GRAFT EXPERIMENTS. "It was proposed by Chailakhyan (1936) more than half a century ago that the signal passing between leaves and response sites is a specific flowering hormone: florigen. This idea was based on a series of experiments showing that grafting of leaves from one donor species to a separate receptor species could cause flowering. This strongly suggested the participation of common signals in different species." https://lnkd.in/d_f7kfY View in LinkedIn

CONTROL BY INHIBITION. "Other grafting experiments suggested that other substances inhibiting flowering may be involved; the appropriate day-length would then lead to removal of an antiflorigen rather than (or in addition to) synthesis of a floral hormone." https://lnkd.in/d_f7kfY View in LinkedIn

DEFAULT FLOWERING. "Flowering is generally regarded as a default process that will occur at some point in the plant’s life. The time that a plant flowers, however, is affected by many environmental and endogenous factors and consequently there are numerous genetic pathways that are involved in the control of flowering time." https://lnkd.in/d_f7kfY View in LinkedIn