Project description:Virus infection and over expression of protein in cytosol induce a subset of HSP70s. We named this response the Cytosolic Protein Response (CPR) and have been investigating it in the context of a parallel mechanism in the soluble cytosol with the UPR, and as a subcomponent of the larger HS response. This experiment was carried out to study the transcriptional aspect of CPR. In this analysis, we have triggered CPR by infiltrating proline analogue, L-azetidine-2-carboxylic acid (AZC) into Arabidopsis mature leaves. Since AZC trigger unfolded protein response(UPR) in ER as well as CPR, we have included tunicamycin treatment, which is a specific inducer of UPR to subtract the effect of UPR from the AZC response. Heat shocked samples were included to identify CPR as a subcomponent of larger HS response. We used microarray data to identify the genes upregurated by CPR. These genes were commonly upregulated by AZC and HS but not by tunicamycin treatment. Experiment Overall Design: Arabidopsis mature leaves were infiltrated with AZC or L-Proline (control of AZC) and tunicamycin or DMF(solvent control of tunicamycin). For the heat shock treatment, six mature leaves were detached from plant and incubated at 37 °C or 20°C (as a control) for a period of 1h. The experiment was repeated three times for AZC and HS treatment (3 biological replication). Tunicamycin experiment was repeated five times due to large valiation in the responses (5 biological replication).
Project description:Anoxia induces several heat shock proteins and a heat pre-treatment can acclimatize Arabidopsis seedlings to a subsequent anoxic treatment. In this work we analyzed the response of Arabidopsis seedlings to anoxia, heat and a combined heat+anoxia stress. A significant overlapping between the anoxic and heat shock responses has been observed by whole-genome microarray analysis.
Project description:Heat Shock Factor 1 (Hsf1) in yeast drives the basal transcription of key proteostasis factors and its activity is induced as part of the core heat shock response. In this study we stringently test the role of Hsf1 under basal and stress conditions using a newly constructed hsf1∆ strain. To assess how cells mount transcriptional stress responses when Hsf1 is inactivated, we performed mRNA-sequencing (mRNA-seq) upon hear shock (HS) or treatment with azetidine-2-carboxylic acid (AzC).
Project description:Summary: The non-protein amino acid beta-aminobutyric acid (BABA) primes Arabidopsis to respond more quickly and strongly to pathogen and osmotic stress. Here, we report that BABA also significantly enhanced acquired thermotolerance in Arabidopsis. This thermotolerance was dependent on heat shock protein 101, a critical component of the normal heat shock response. BABA did not enhance basal thermotolerance under a severe heat shock treatment. No roles for the hormones ethylene and salicylic acid in BABA-induced acquired thermotolerance were identified by mutant analysis. By global gene expression analysis, transcript levels for several transcription factors and DNA binding proteins regulating responses to the stress hormone abscisic acid (ABA) were found to be elevated in BABA-treated relative to water-treated plants. The role of ABA in BABA-induced thermotolerance was complex. BABA-enhanced thermotolerance was partially compromised in the ABA-insensitive mutant, abi1-1, but was augmented in abi2-1. In an unrelated process, BABA, like ABA, inhibited root growth and the level of inhibition was roughly additive in roots treated with both compounds. Root growth of both abi1-1 and abi2-1 was also inhibited by BABA. Unexpectedly, abi1-1 and abi2-1 root growth was inhibited more strongly by combined ABA and BABA treatments than by BABA alone. Our results together with previously published data suggest that BABA is a general enhancer of plant stress resistance and that cross-talk occurs between BABA and ABA signalling cascades. Specifically, the BABA-mediated accumulation of ABA transcription factors without concomitant activation of a downstream ABA response could represent one component of the BABA-primed state in Arabidopsis. Overall design: A replicate experimental design type is where a series of replicates are performed to evaluate reproducibility or as a pilot study to determine the appropriate number of replicates for a subsequent experiments. Keywords: replicate_design
Project description:Subspecies of the Atlantic killifish, Fundulus heteroclitus, differ in their maximum thermal tolerance. To determine whether there is a link between the heat shock response (HSR) and maximum thermal tolerance, we exposed 20ºC acclimated killifish from these subspecies to a 2hr heat shock at 34ºC and examined gene expression during heat shock and recovery using real time quantitative PCR and a heterologous cDNA microarray designed for salmonid fishes. Keywords: Expression profiling by array
Project description:We evaluated the effect of a 2h pre-treatment at 38°C on the response of Arabidopsis thaliana 6d-old seedlings to a 2h heat shock at 43°C applied 24 h later. A shotgun proteomics approach using total protein extracts was used to compare the proteome of seedlings from four type of samples, using 4 replicates: C=Control (just before heat shock on day 7) P= Primed (on day 7, 22 h after priming performed on day 6) H= Heat shock (on day 7, 2h after heat shock) PH= Priming + heat shock (on day 7, for primed seedlings, 2h after heat shock).
Project description:ESTs in which transcription levels in oyster gill differed among sampling times after heat shock and between families with high or low survival of heat shock were identified through expression profiling of 1,675 spot pairs Keywords: comparison of families characterized by low or high survival after heat shock