Project description:Transcriptional profiling of dark-grown Arabidopsis seedlings comparing SCR:PIF1/pifQ transgenic plant with pif1pif3pif4pif5 quadruple mutant (pifQ). Seedlings were grown under dark condition for 2.5 days. Goal was to determine the effects of endodermal PIF1 in dark-grown seedlings. Two-condition experiment, SCR:PIF1/pifQ vs. pifQ Biological replicates: 3 pifQ replicates, 3 SCR:PIF1 replicates.
Project description:Transcriptional profiling of dark-grown Arabidopsis seedlings comparing SCR:PIF1/pifQ transgenic plant with pif1pif3pif4pif5 quadruple mutant (pifQ). Seedlings were grown under dark condition for 2.5 days. Goal was to determine the effects of endodermal PIF1 in dark-grown seedlings.
Project description:Seedling hypocotyls display negative gravitropism in the dark but agravitropism in the light. The Arabidopsis thaliana pif quadruple mutant (pifQ), which lacks four PHYTOCHROME-INTERACTING FACTORS (PIFs), is agravitropic in the dark. Endodermis-specific expression of PIF1 rescues gravitropism in pifQ mutant seedlings. Since phytochromes induce light responses by inhibiting PIFs and the COP1-SPA ubiquitin E3 ligase complex in the nucleus, we asked whether phyB can cell autonomously inhibit hypocotyl negative gravitropism in the endodermis. We found that while epidermis-specific expression of PHYB rescues hypocotyl negative gravitropism and all other phyB mutant phenotypes, endodermis-specific expression of PHYB does not. Epidermal phyB induces the phosphorylation and degradation of endodermal PIFs in response to red light. This induces a global gene expression pattern similar to that induced by red light treatment of seedlings expressing PHYB under the control of its own endogenous promoter. Our results imply that epidermal phyB generates an unidentified mobile signal that travels to the endodermis where it promotes PIF degradation and inhibits hypocotyl negative gravitropism.
Project description:Transcriptional profiling of the vegetative part of Arabidopsis comparing wild type with the shr scl23 scr triple mutant. The latter is produced by crossing the strong null alleles of shr (shr-2), scl23 (scl23-1) and scr (scr-5). The goal was to determine the effects of the GRAS transcription factors SHR, SCL23 and SCR on growth and development of the Arabidopsis shoot system by global transcriptome analysis. Two-condition experiment: Col-0 vs. shr scl23 scr triple mutant. Biological replicates: 2 WT vs. triple mutant replicates, 2 WT vs. triple mutant replicates dye-swap replicates.
Project description:We sequenced mRNA from WT and PhytochromeInteractingFactor (pif) mutant seedlings grown for 2d in darkness. Transcriptome profiles of the wild-type (WT), pif1, pif3, pif, pif5 monogenic mutants, pif3pif4pif5 (pif345), pif1pif4pif5(pif145), pif1pif3pif5 (pif135) and pif1pif3pif4 (pif134) triple mutants and pif1pif3pif4pif5 (pifq) quadruple mutant seedlings. Biological triplicate samples were analyzed from libraries constructed using a 3'-capture, 5' to 3' directional method.
Project description:First series collects endodermal cells using the SCR::GFP promoter after treatment with auxin Second series includes comparative samples of jkd vs. wild type plants for specific tissues; QC and meristem
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).
Project description:The Saccharomyces cerevisiae gene PIF1 encodes a conserved eukaryotic DNA helicase required for both mitochondrial and nuclear DNA integrity. Our previous work revealed that a pif1D strain is tolerant to zinc overload. We demonstrate here that this effect is independent of the Pif1 helicase activity and is only observed when the protein is absent from the mitochondria. pif1 cells accumulate abnormal amounts of mitochondrial zinc and iron. Transcriptional profiling reveals that pif1 cells under standard growth conditions overexpress aconitase-related genes. When exposed to zinc, pif1 cells show lower induction of genes encoding iron (siderophores) transporters and higher expression of genes related to oxidative stress responses than wild type cells. Coincidently, pif1 mutants are less prone to zinc-induced oxidative stress and display a higher reduced/oxidized glutathione ratio. Strikingly, although pif1 cells contain normal amounts of the Aco1 protein, they completely lack aconitase activity. Loss of Aco1 activity is also observed when the cell expresses a non-mitochondrially targeted form of Pif1. We postulate that lack of Pif1 forces aconitase to play its DNA protective role as nucleoid protein and that this would trigger a domino effect on iron homeostasis resulting in increased zinc tolerance. Four samples were analyzed: WT and pif1 mutant both, in the presence and in the absence of 5 mM ZnCl2 for 1 h. We compared the expression profile of: 1) WT+Zn vs WT-Zn, 2) pif1 mutant+Zn vs pif1 mutant-Zn, 3) pif1 mutant vs WT, and 4) pif1 mutant+Zn vs WT+Zn. A Dye-swap was carried out for each comparison of samples. Total number of chips analyzed: 8.