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).
Project description:Transcriptional profiling of 60h-old Arabidopsis whole seedlings comparing control Col-0 wild-type plants with pifQ mutant plants The expression profile of dark-grown pifQ mutant shows similar pattern of Rc-grown Col-0 wild-type Keywords: Genetic modification
