Project description:The plant hormone gibberellin (GA) represents an important regulator of growth and development. Early transcriptional events controlled by GA are not well characterised. Previous microarray studies have identified genes responsive to GA treatment in the whole seedling. The whole seedling represents many tissues where subtle effects of GA treatment in specific tissues may be masked. When treated with GA, an effect on the growth rate of roots was observed. More specifically, the shorter root of a GA-deficient plant can be rescued to wild-type length by the application of GA. This experiment was designed to identify GA-regulated genes in the root tips of Arabidopsis. The use of a GA-deficient mutant provides a greater potential to identify genes responding to GA treatment. Root tips are ideally suited for the quick uptake of the hormone treatment. There will be two biological replicates which will each consist of a control treatment at 0 minutes and 2 hours, as well as the experimental GA-treated 2 hour time point. This system provides an opportunity to compare gene expression between treated and non-treated root tips and allow the identification of early GA-responsive genes.
Project description:The plant hormone gibberellin (GA) represents an important regulator of growth and development. Early transcriptional events controlled by GA are not well characterised. Previous microarray studies have identified genes responsive to GA treatment in the whole seedling. The whole seedling represents many tissues where subtle effects of GA treatment in specific tissues may be masked. When treated with GA, an effect on the growth rate of roots was observed. More specifically, the shorter root of a GA-deficient plant can be rescued to wild-type length by the application of GA. This experiment was designed to identify GA-regulated genes in the root tips of Arabidopsis. The use of a GA-deficient mutant provides a greater potential to identify genes responding to GA treatment. Root tips are ideally suited for the quick uptake of the hormone treatment. There will be two biological replicates which will each consist of a control treatment at 0 minutes and 2 hours, as well as the experimental GA-treated 2 hour time point. This system provides an opportunity to compare gene expression between treated and non-treated root tips and allow the identification of early GA-responsive genes. 6 samples were used in this experiment.
Project description:The Arabidopsis thaliana REPRESSOR OF GA gene (RGA) encodes a DELLA protein that associates with multiple transcription factors to control plant growth in response to the hormone gibberellin (GA) (1). As part of a screen for genes that mediate the function of RGA in stem growth and shoot meristem function, we performed ChIP-seq to identify genome-wide loci associated with RGA in inflorescence apices. To detect genes controlled by RGA in a gain-of-function semi-dwarf background, we used a GFP-tagged, gibberellin-insensitive version of RGA (RGAp:GFP-rga-delta17) (2). (1) J.-M. Daviere, P. Achard, Gibberellin signaling in plants. Development 140, 1147-1151 (2013). (2) A. Dill, T. P. Sun, Synergistic derepression of gibberellin signaling by removing RGA and GAI function in Arabidopsis thaliana. Genetics 159, 777-785 (2001).
Project description:Transcriptional profiling in the root between ga1, ga1 scl3 and ga1 SCL3 OE. We used Affymetrix ATH1 microarrays to determine the effect of GRAS transcription factor SCL3 and gibberellin on the growth and development of the Arabidopsis root system by global transcriptome analysis and to identify new regulators in the regulatory pathway.
Project description:The aim of the experiment was to identify early gibberellin (GA) responsive genes in the roots of an Arabidopsis GA deficient mutant.The GA deficient mutant used in this study is a transgenic line overexpressing the PcGA2ox1 gene. This mutant has an identical phenotype to ga1-3, but it does not require exogenous GA treatment for germination.Seeds were germinated on 1xMS + 1% (w/v) sucrose plates containing 0.7% gelrite, and grown under continous light. The plates were orientated vertically.After six days growth the plates were treated with or without 5uM GA4 for 0, 30, 60 and 180 minutes.Approximately 400 hypocotyls were harvested per timepoint using a razorblade and after excision the hypocotyls were frozen in liquid nitrogen giving a total of 7 experimental samples (1: untreated, 2: 30 mins GA4, 3: 30 mins untreated, 4: 60 mins GA4, 5: 60 mins untreated, 6: 180 mins GA4, 7: 180 mins untreated. Three biological replicates were performed giving a total of 21 root samples. Total RNA was isolated from the roots using the QIAGEN RNeasy method. Keywords: Expression profiling by array