Similar Datasets
Project description:We report the transcriptomic response of Arabidopsis thaliana seedlings grown in continuous white light, darkness or darkness and 1 hour of red light
2022-03-09 | GSE181167 | GEO
Project description:We report the changes in H3K9ac in Arabidopsis thaliana seedlings grown in continuous white light, darkness or darkness and 1 hour of red light
2022-03-09 | GSE181432 | GEO
Project description:Light initiates the seedling deetiolation transition by promoting major changes in gene expression mainly regulated by phytochrome (phy) photoreceptors. During the initial dark-to-light transition, phy photoactivation induces rapid changes in gene expression that eventually lead to the photomorphogenic development. Recent reports indicate that this process is achieved by phy-induced degradation of Phy-Interacting bHLH transcription Factors (PIFs) PIF1, PIF3 PIF4 and PIF5, which are partly redundant constitutive repressors of photomorphogenesis that accumulate in darkness. In order to test whether light/phy-regulated gene expression occurs through these PIFs, we have performed whole-genome expression analysis in the pif1pif3pif4pif5 quadruple mutant (pifq). Wild-type and pifq mutant seeds were plated on GM medium without sucrose at room temperature. During this procedure the seeds were routinely exposed to white light (WL) for a total of 1.5 hours after imbibition. Seeds were then stratified for 5 days at 4ºC in darkness, induced to germinate with a 5-min red pulse (Rp) (46 μmol/m2/s) and then incubated in the dark for 3h at 21°C before exposure to a terminal 5-min far red pulse (FRp) (58 μmol/m2/s) to suppress pseudo-dark effects. Seeds were then placed in either dark (D) or constant red light (Rc) (6.7 μmol/ m2/s) at 21°C for 45h (2d-old seedlings). Alternatively, 2d-old dark-grown seedlings were treated with 1h of red light (R1) (7.5 μmol/m2/s). Seed samples were harvested after stratification (5d stratified seeds).
2009-10-31 | E-GEOD-17159 | biostudies-arrayexpress
Project description:Circadian clocks are gene networks producing 24-h oscillations at the level of clock gene expression that is synchronized to environmental cycles via light signals. The ELONGATED HYPOCOTYL 5 (HY5) transcription factor is a signalling hub acting downstream of several photoreceptors and is a key regulator of photomorphogenesis. Here we describe a mechanism by which light quality could modulate the pace of the circadian clock through controlling abundance of HY5. We show that hy5 mutants display remarkably shorter period rhythms in blue but not in red light or darkness and blue light is more efficient than red to induce accumulation of HY5 at transcriptional and post-transcriptional levels. We demonstrate that the pattern and level of HY5 accumulation modulates its binding to specific promoter elements of majority of clock genes, but only a few of these show altered transcription in the hy5 mutant. Mathematical modelling suggests that the direct effect of HY5 on the apparently non-responsive clock genes could be masked by feed-back from the clock gene network. We conclude that the information on the ratio of blue and red components of the white light spectrum is decoded and relayed to the circadian oscillator, at least partially, by HY5.
2018-09-05 | GSE117797 | GEO
Project description:To determine the functional relevance of the HY5 binding sites to the transcriptional regulation, we performed genome wide expression analysis using WT and hy5 grown in continuous white light for 4 days. Keywords: mutant/widetype comparative
2007-03-01 | GSE6517 | GEO
Project description:Plants respond to changes in the red:far red ratio (R:FR) of incident light. A reduction in this ratio (increase in FR) results in the Shade Avoidance Response (SAR) with associated changes in gene expression. The Phyotchrome-Interacting Factors (PIFs) are bHLH transcription factors known to be involved in the SAR. An analysis of changes in gene expression in WT and quadruple pif1pif3pif4pif5 (pifq; Leivar et al., 2008 (PMID 19920208)) mutant seedlings in response to an increase in FR should identify primary targets of PIF signaling. We used microarrays to examine the SAR in WT (Columbia) and pifq mutant Arabidopsis seedlings. Arabidopsis WT and pifq mutant seeds were plated on GM medium without sucrose at room temperature. During this procedure, the seeds were routinely exposed to white light (WL) for a total of 1.5 hours after imbibition. Seeds were then stratified for 5 days at 4ºC in darkness, and then grown in WL (19 umol/m2/s, R/FR ratio of 6.48) for 2 days at 21°C (WL0 samples). Two-day-old WL-grown seedlings were then maintained in the same fluence rate of WL supplemented with far-red light (WL-FR, R/FR ratio of 0.006) for 1 (FR1), 3 (FR3) or 24 (FR24) hours before harvesting. Control seedlings were also maintained in parallel in the same fluence rate of WL for 24h (WL24) before harvesting. Three different biological replicates of each treatment were grown separately and extracted, processed, and analyzed independently.
2012-08-01 | E-GEOD-28297 | biostudies-arrayexpress
Project description:RNA-seq experiment of WT and pifq mutant seedlings grown for 3 days in darkness in presence or absence of Lincomycin.
2016-03-08 | GSE78969 | GEO
Project description:Although landscapes of several epigenetic marks are now available for Arabidopsis and rice, such profiles remain static and do not provide information about dynamic changes of plant epigenomes in response to developmental or environmental cues. Here we analyzed the effects of light regulation on four epigenetic histone modifications (H3K9ac, H3K9me3, H3K27ac, H3K27me3). Our genome-wide profiling of H3K9ac and H3K27ac revealed that these modifications are gene-specific. In contrast, we found that H3K9me3 and H3K27me3 target genes, but also intergenic-regions and transposable elements. Specific light conditions affected the number of epigenetically modified regions, as well as the overall correlation strength between the presence of specific epigenetic modifications and transcription. Futhermore, we observed that acetylation is an important contributor to light-regulated genome expression not only through its activating action on HY5 and HYH but also on their downstream targets. We found that dynamic acetylation changes in response to light have a major role in the active regulation of photosynthetic gene expression, while H3K27ac and H3K27me3 are major contributors to light regulation of the gibberellin metabolism. We also identified distinct epigenetic patterns in the epigenome of the photomorphogenic mutant cop1-4, suggesting that COP1 might have a role in the establishment of specific epigenetic modifications. Thus, this work provides a dynamic portrait of the variations in histone modifications in response to the plantM-bM-^@M-^Ys changing light environment and strengthens the concept that epigenetic modifications represent another layer of control for light-regulated genes involved in photomorphogenesis. Arabidopsis ecotype Columbia (Col-0) was the genetic background used for this study. Seeds were stratified for two days at 4M-BM-0C, then germinated and grown for five days at 22M-BM-0C in continuous darkness (D). Six hours before harvest, a number of plates were transferred to continuous white light (D to L). The cop1-4 mutant was also used in this study. Seedlings from the different conditions and genotypes were harvested at the same time of day. Chromatin was immunoprecipitated, washed, reverse crosslinked, amplified and hybridized according to AffymetrixM-bM-^@M-^Y Chromatin Immunoprecipitation Assay Protocol Rev.3. Three M-NM-<l of the following antibodies were used: anti-H3K9ac (Upstate 06-942), anti-H3K9me3 (Upstate 07-442), anti-H3K27ac (Upstate 07-360), anti-H3K27me3 (Upstate 07-449), and anti-H3 (Upstate 07-690). Four biological replicates were hybridized to tiling arrays.
2009-12-30 | E-GEOD-15597 | biostudies-arrayexpress
Project description:Light initiates the seedling deetiolation transition by promoting major changes in gene expression mainly regulated by phytochrome (phy) photoreceptors. During the initial dark-to-light transition, phy photoactivation induces rapid changes in gene expression that eventually lead to the photomorphogenic development. Recent reports indicate that this process is achieved by phy-induced degradation of Phy-Interacting bHLH transcription Factors (PIFs) PIF1, PIF3 PIF4 and PIF5, which are partly redundant constitutive repressors of photomorphogenesis that accumulate in darkness. In order to test whether light/phy-regulated gene expression occurs through these PIFs, we have performed whole-genome expression analysis in the pif1pif3pif4pif5 quadruple mutant (pifq).
2009-11-01 | GSE17159 | GEO
Project description:A tuberization inhibitor has long been postulated, but not yet found. We found that blue light inhibits tuberization in Norland, a day-neutral variety of Solanum tuberosum L. Tissue-cultured plants formed tubers within 8 weeks under continuous darkness, and white, red, or far-red light. Preliminary experiments indicated that a one- or two-day exposure to blue light after 3-4 weeks of dark treatment will inhibit tuber formation in ‘Norland’ plants. Using this system and expression profiling, we may be able to identify candidate tuberization inhibitors. 'Norland' plants (subcultured from existing cultures and grown for two weeks under continuous 100 umol/m2-s white fluorescent light) were placed in tuber-inducing media containing 6% sucrose, vitamins, MS salts, and kinetin (2.5 mg/L). Tubes containing plants were wrapped in two layers of aluminum foil. After 3 weeks and 2 days, half of the tubes were exposed to 6-7 umol/m2-s blue light. The other half of the tubes were left in darkness (controls). After 2 days, all plants were harvested and frozen in liquid nitrogen. Plants exposed to blue light were harvested under blue light. Control plants were harvested under < 2 umol/m2-s light conditions. All plant transfers were done at 1700 (5 PM) to avoid possible complications due to circadian effects. Experiments were performed four times, from subculture to harvest. RNA was extracted from stem and leaf tissue of plants using the Qiagen RNeasy Plant Mini kit. Extracted RNA was then converted to dsDNA using the Invitrogen protocol and reagents for double stranded cDNA synthesis. The resulting dsDNA was in vitro transcribed into amplified RNA using the Ambion procedure and reagents for in vitro transcription. cDNA was purified using Qiagen MinElute columns and protocol. Amplified RNA was purified using Ambion columns or Qiagen RNeasy columns and the Ambion protocol, and quantified using RiboGreen dye fluorometry. Keywords: Direct comparison
2008-02-13 | GSE10491 | GEO