In response to WRKY40 and WRKY60 perturbation (and high light stress), significant transcriptional re-programming occurs particularly for genes encoding stress responsive mitochondrial and choloplast proteins.
AtWRKY40 and AtWRKY63 modulate the expression of stress-responsive nuclear genes encoding mitochondrial and chloroplast proteins.
Specimen part, Treatment
View SamplesDrought is an important environmental factor affecting plant growth and biomass production. Despite this importance, little is known on the molecular mechanisms regulating plant growth under water limiting conditions. The main goal of this work was to investigate, using a combination of growth and molecular profiling techniques, how Arabidopsis thaliana leaves adapt their growth to prolonged mild osmotic stress. Fully proliferating, expanding and mature leaves were harvested from plants grown on plates without (control) or with 25mM mannitol (osmotic stress) and compared to seedlings at stage 1.03.
Developmental stage specificity and the role of mitochondrial metabolism in the response of Arabidopsis leaves to prolonged mild osmotic stress.
Specimen part
View SamplesMitochondrial stress stimuli such as AA caused a transient suppression of auxin signaling and conversely, auxin treatment represses a part of the response to AA treatment.
A Functional Antagonistic Relationship between Auxin and Mitochondrial Retrograde Signaling Regulates Alternative Oxidase1a Expression in Arabidopsis.
Treatment
View SamplesOverexpression of VEGF (vascular endothelial growth factor) in the germinal matrix of the brain causes GMH-IVH-like anomalies (Germinal matrix hemorrhage [GMH]; intraventricular hemorrhage [IVH]).
Overexpression of vascular endothelial growth factor in the germinal matrix induces neurovascular proteases and intraventricular hemorrhage.
Specimen part
View SamplesStresses that target mitochondrial function lead to altered transcriptional responses for 100-1000s of genes genome wide, and are signalled via retrograde communication pathways within the cell. rao2 mutants contain a mutation in the NAC family transcription factor ANAC017 and cannot induce stress responsive genes (such as the mitochondrial alternative oxidase 1a) in response to mitochondrial dysfunction. We sought to define the global gene network regulated through RAO2 function in response to mitochondrial stress (mimicked through treatment of plants with antimycin A - a specific inhibitor of complex III in the mitochondrial electron transfer chain), and non-specific stress signals such as hydrogen peroxide. We have defined global stress responses that are positively and negatively mediated by RAO2 function, and show that greater than 80% of transcripts that are differentially regulated under H2O2 stress require proper functioning of ANAC017 for a normal stress responses.
A membrane-bound NAC transcription factor, ANAC017, mediates mitochondrial retrograde signaling in Arabidopsis.
Treatment
View SamplesArabidopsis ATH1 Genome Arrays were used to analyse changes in transcript abundance between Col-0 (wild-type) Arabidopsis seedlings and either single T-DNA insertional KO mutants of LETM1 (At3g59820)(T-DNA lines; SALK_067558C (letm1-1) and SALK_058471 (letm1-2)) or LETM2 (At1g65540) (T-DNA line; SALK_068877 (letm2-1)). Additionally, letm1 and letm2 knock out Arabidopsis lines were crossed to generate double mutants, however a double knock-out of these two genes results in an embryo lethal phenotype. Hemizygous plants were generated that were homozygous knock out for LETM1 and heterozygous knock out for LETM2, and visa versa, termed (letm1(-/-)LETM2(+/-) and (LETM1(+/-)letm2(-/-) respectively. Note that (letm1(-/-)LETM2(+/-) displays a mild developmental defective phenotype in the first 10-14 days of growth, while (LETM1(+/-)letm2(-/-) shows no phenotype. Microarray analysis was carried out on all three single homozygous knock out lines, and also on both combinations of the hemizygous mutation between the two genes, and compared with a wild-type Col-0 control to gain insight into global transcript abundance changes in these mutant lines. Arrays were performed in triplicate for each genotype, from RNA isolated from 3 independent pools of 5-10 Arabidopsis seedlings at 10 days old.
LETM proteins play a role in the accumulation of mitochondrially encoded proteins in Arabidopsis thaliana and AtLETM2 displays parent of origin effects.
Age, Specimen part
View SamplesThe translocase of the inner membrane 17-1 (Tim17-1) plays a defined role in germination in Arabidopsis thaliana
The mitochondrial protein import component, TRANSLOCASE OF THE INNER MEMBRANE17-1, plays a role in defining the timing of germination in Arabidopsis.
Specimen part, Time
View SamplesTranscript profiling of transgenic Arabidopsis thaliana seedlings constitutively overexpressing UGT74E2 (35S::UGT74E2).
Perturbation of indole-3-butyric acid homeostasis by the UDP-glucosyltransferase UGT74E2 modulates Arabidopsis architecture and water stress tolerance.
Specimen part
View SamplesGene expression levels are determined by the balance between rates of mRNA transcription and decay, and genetic variation in either of these processes can result in heritable differences in transcript abundance. Although the genetics of gene expression has been the subject of intense interest, the contribution of heritable variation in mRNA decay rates to gene expression variation has received far less attention. To this end, we developed a novel statistical framework and measured allele-specific differences in mRNA decay rates in a diploid yeast hybrid created by mating two genetically diverse parental strains. In total, we estimate that 31% of genes exhibit allelic differences in mRNA decay rate, of which 350 can be identified at a false discovery rate of 10%. Genes with significant allele-specific differences in mRNA decay rate have higher levels of polymorphism compared to other genes, with all gene regions contributing to allelic differences in mRNA decay rate. Strikingly, we find widespread evidence for compensatory evolution, such that variants influencing transcriptional initiation and decay having opposite effects, suggesting steady-state gene expression levels are subject to pervasive stabilizing selection. Our results demonstrate that heritable differences in mRNA decay rates are widespread, and are an important target for natural selection to maintain or fine-tune steady-state gene expression levels. Overall design: We measured rates of allele-specific mRNA decay (ASD) in a diploid yeast produced by mating two genetically diverse haploid Saccharomyces cerevisiae strains: the laboratory strain BY4716 (BY), which is isogenic to the reference sequence strain S288C, and the wild Californian vineyard strain RM11-1a (RM). Briefly, we introduced rpb1-1, a temperature sensitive mutation in an RNA polymerase II subunit, to each of the haploid yeast strains, mated the strains, and grew the resulting hybrid diploid to mid-log phase at 24 °C, before rapidly shifting the culture to 37 °C to inhibit transcription. RNA-seq was performed on culture samples taken at 0, 6, 12, 18, 24, and 42 minutes subsequent to the temperature shift. To identify ASD, we used transcribed polymorphisms to distinguish between parental transcripts, and compared the relative levels of transcript abundance over the time course. Note, this experimental design internally controls for trans-acting regulatory variation as well as environmental factors. Under the null hypothesis of no ASD, the proportion of reads from the BY transcript (p_BY = N_BY / (N_BY + N_RM)) observed over the time course remains unchanged. However, genes with ASD will exhibit an increasing or decreasing proportion of BY reads as a function of time. In total, we measured ASD from three independent biological replicates.
Heritable variation of mRNA decay rates in yeast.
Disease, Cell line, Subject
View SamplesWe report the transcriptome changes that result of the genomic deletion of one or two alleles of an islet-specific long non-coding RNA (Blinc1) in isolated pancreas from e15.5 mouse embryos. Overall design: Pancreas from e15.5 embryos were dissected and total RNA extracted. Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the mouse genome (UCSC/mm9) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq.
βlinc1 encodes a long noncoding RNA that regulates islet β-cell formation and function.
Specimen part, Subject
View Samples