Heat shock response in Arabidopsis Hsa32 knockout mutant
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE4062 | GEO | 2006/03/20
SECONDARY ACCESSION(S): PRJNA95209
REPOSITORIES: GEO
Similar Datasets
Project description:Plants and animals share similar mechanisms in the heat-shock (HS) response, such as synthesis of the conserved HS proteins (Hsps). However, because plants are confined to a growing environment, in general they require unique features to cope with heat stress. We have analyzed the function of a novel Hsp, heat-stress-associated 32-kD protein (Hsa32), which is highly conserved in land plants but absent in most other organisms. The gene responds to HS at the transcriptional level in moss, Arabidopsis, and rice. Like other Hsps, Hsa32 protein accumulates greatly in Arabidopsis seedlings after HS treatment. Disruption of Hsa32 by T-DNA insertion does not affect growth and development under normal conditions. However, the acquired thermotolerance in the knockout line was compromised following a long recovery period (> 24 h) after an acclimation HS treatment, when a severe HS challenge killed the mutant but not the wild-type plants, but no significant difference was observed if they were challenged within a short recovery period. Microarray analysis of the knockout mutant indicates that only the expression of Hsa32 was significantly altered in HS response. Taken together, our results suggest that Hsa32 is not required for the induction but maintenance of acquired thermotolerance. This report provides direct evidence that a plant-specific Hsp plays an important role in thermotolerance.
2007-06-27 | E-GEOD-4062 | biostudies-arrayexpress
Project description:The expression of heat-shock proteins (Hsps) induced by a non-lethal heat treatment confers acquired thermotolerance (AT) to organisms against a subsequent challenge of otherwise lethal temperature. After stress signal lifted, AT gradually decayed with the decline of Hsps during recovery period. The duration of AT may be critical for sessile organisms, such as plants, to survive repeated heat stress in the environment. To identify heat-induced genes involved in duration of AT, we took a reverse-genetics approach by screening for Arabidopsis T-DNA insertion mutants that show decreased thermotolerance after a long recovery at non-stress condition following a conditioning treatment. Among the tested mutants corresponding to 47 genes, only the HsfA2 knockout mutant showed significant phenotype. The mutant plants were more sensitive to severe heat stress than the wild type after long but not short recovery following a pretreatment at 37oC, which can be complemented by introducing a wild-type copy of the gene. Quantitative hypocotyl elongation assay also revealed that AT decayed faster in the absence of HsfA2. Significant decline of the transcript levels of several highly heat-induced genes was observed in the HsfA2 knockout plants after a 4-h recovery or after 2 h of prolonged heat stress. Immunoblot anlysis showed that Hsa32 and class I small Hsp were lower in the mutant than in the wild type after a long recovery. Our results suggest that HsfA2 as a heat-induced transactivator sustains the post-stress expression of Hsp genes and extends the duration of AT in Arabidopsis. Experiment Overall Design: Total RNA was isolated from the seedlings of 5-d old wild-type and HsfA2 knockout mutant seedlings (a pool of about 100 plants per treatment in duplicates) harvested immediately after heat shock treatment. In this experiment, total 12 chips were used, 1 each for 2 biological replicates of the control and HS-treated samples for the wild type and mutant plants.
2008-06-13 | E-GEOD-4760 | biostudies-arrayexpress
Project description:The expression of heat-shock proteins (Hsps) induced by a non-lethal heat treatment confers acquired thermotolerance (AT) to organisms against a subsequent challenge of otherwise lethal temperature. After stress signal lifted, AT gradually decayed with the decline of Hsps during recovery period. The duration of AT may be critical for sessile organisms, such as plants, to survive repeated heat stress in the environment. To identify heat-induced genes involved in duration of AT, we took a reverse-genetics approach by screening for Arabidopsis T-DNA insertion mutants that show decreased thermotolerance after a long recovery at non-stress condition following a conditioning treatment. Among the tested mutants corresponding to 47 genes, only the HsfA2 knockout mutant showed significant phenotype. The mutant plants were more sensitive to severe heat stress than the wild type after long but not short recovery following a pretreatment at 37oC, which can be complemented by introducing a wild-type copy of the gene. Quantitative hypocotyl elongation assay also revealed that AT decayed faster in the absence of HsfA2. Significant decline of the transcript levels of several highly heat-induced genes was observed in the HsfA2 knockout plants after a 4-h recovery or after 2 h of prolonged heat stress. Immunoblot anlysis showed that Hsa32 and class I small Hsp were lower in the mutant than in the wild type after a long recovery. Our results suggest that HsfA2 as a heat-induced transactivator sustains the post-stress expression of Hsp genes and extends the duration of AT in Arabidopsis. Keywords: heat shock response
2006-11-01 | GSE4760 | GEO
Project description:The expression of heat shock proteins is considered a central adaptive mechanism to heat stress. This study investigated the expression of heat shock proteins (HSPs) and other stress-protective proteins against heat stress in cowpea genotypes under field (IT-96D-610 and IT-16) and controlled (IT-96D-610) conditions. Plants in the control environment were under 25/20°C (day/night) in a warm chamber and 40/25 °C in a hot chamber. In the field, plants grew at Eensaamheid with 26 to 28°C and at Marapyane with 30 to 32°C monthly average maximum temperatures. Heat stress response analysis of proteins at 72 h in the controlled environment showed 270 differentially regulated proteins identified using label-free quantitative proteomics in IT-96D-610 plants. These plants expressed HSPs and chaperones (BAG family molecular chaperone 6 (BAG6), Multiprotein bridging factor1c (MBF1C) and cold shock domain protein 1 (CSDP1)) in the controlled environment. However, IT-96D-610 plants expressed a wider variety of small HSPs and more HSPs in the field. IT-96D-610 plants also responded to heat stress by exclusively expressing chaperones (DnaJ chaperones, universal stress protein and heat shock binding protein (HSBP)) and non-HSP proteins (Deg1, EGY3, ROS protective proteins, temperature-induced lipocalin and succinic dehydrogenase). Photosynthesis recovery and induction of proteins related to photosynthesis, were better in IT-96D-610 because of the concurrent induction of heat stress response proteins for chaperone functions, protein degradation for repair and ROS scavenging proteins and PSII operating efficiency (Fq’/Fm’) than IT-16. This study contributes to identification of thermotolerance mechanisms in cowpea that can be useful in knowledge-based crop improvement.
2022-08-08 | PXD035418 | Pride
Project description:In Drosophila larvae, acquired synaptic thermotolerance following heat shock has previously been shown to correlate with the induction of heat shock proteins (Hsps) including HSP70. We tested the hypothesis that synaptic thermotolerance would be significantly diminished in a temperature-sensitive strain (hsf4) which has been reported not to be able to produce inducible Hsps in response to heat shock. Contrary to our hypothesis, considerable thermoprotection was still observed at hsf4 larval synapses following heat shock. To investigate the cause of this thermoprotection, we conducted DNA microarray experiments to identify heat-induced transcript changes in these organisms. Transcripts of the hsp83, dnaJ-1(hsp40) and gstE1 genes were significantly up-regulated in hsf4 larvae after heat shock. In addition, increases in the levels of Hsp83 and DnaJ-1 proteins but not in the inducible form of Hsp70 were detected by Western blotting. The mode of heat shock administration differentially affected the relative transcript and translational changes for these chaperones. These results indicate that the compensatory up-regulation of constitutively expressed Hsps, in the absence of the synthesis of inducible Hsps including HSP70, could still provide substantial thermoprotection to both synapses and the whole organism. Keywords: heat shock response
2005-12-01 | GSE2998 | GEO
Project description:Maintenance of the epigenome is of utmost importance to warrant appropriate cellular functioning Here we analyzed PRC1/2 function, in response to cellular stress. We observe that heat shock (HS) leads to nucleolar accumulation of CBX proteins, and are strongly immobilized in a 1,6-hexanediol insensitive manner, suggestive of a HS-induced liquid-to-solid phase transition of the nucleolus. CBX protein recovery from the nucleolus is dependent on heat shock protein (HSP) activity. LC-MS/MS analyses of nucleoli shows HS-induced nucleolar accumulation of PRC1/2 subunits, various chromatin regulators, HSPs, and the 26S proteasome. Finally, we find that HS leads to a strong reduction of PRC1/2 chromatin binding at target genes and loss of H2AK119ub and H3K27me3. Our findings demonstrate that thermal stress results in a rapid accumulation of epigenetic regulators in the nucleolus, and a concomitant loss of PRC1/2 complex chromatin binding and associated epimarks, underlining that environmental stress directly alters the epigenome.
2019-05-31 | GSE121182 | GEO
Project description:In Drosophila larvae, acquired synaptic thermotolerance following heat shock has previously been shown to correlate with the induction of heat shock proteins (Hsps) including HSP70. We tested the hypothesis that synaptic thermotolerance would be significantly diminished in a temperature-sensitive strain (hsf4) which has been reported not to be able to produce inducible Hsps in response to heat shock. Contrary to our hypothesis, considerable thermoprotection was still observed at hsf4 larval synapses following heat shock. To investigate the cause of this thermoprotection, we conducted DNA microarray experiments to identify heat-induced transcript changes in these organisms. Transcripts of the hsp83, dnaJ-1(hsp40) and gstE1 genes were significantly up-regulated in hsf4 larvae after heat shock. In addition, increases in the levels of Hsp83 and DnaJ-1 proteins but not in the inducible form of Hsp70 were detected by Western blotting. The mode of heat shock administration differentially affected the relative transcript and translational changes for these chaperones. These results indicate that the compensatory up-regulation of constitutively expressed Hsps, in the absence of the synthesis of inducible Hsps including HSP70, could still provide substantial thermoprotection to both synapses and the whole organism. Two strains were used in this study; the mutant cn bw hsf4 strain, and the dp cn bw cl control strain from which the mutant was derived. For each strain, co-reared larvae were separated into a control group and a treatment group at random. RNA from the heat-shocked larvae and from the respective controls were directly compared on cDNA microarrays (GPL311). Two independent biological samples from each genotype were collected. In addition, an inter-strain comparison was made using the RNA from the untreated controls from each genotype. This was also performed in duplicate.
2005-11-30 | E-GEOD-2998 | biostudies-arrayexpress
Project description:Heat shock proteins (Hsps) are molecular chaperones primarily involved in maintenance of protein homeostasis. Their function has been best characterized in heat stress (HS) response during which Hsps are transcriptionally controlled by heat stress transcription factors (Hsfs). The role of Hsfs and Hsps in HS-response in tomato was initially examined by transcriptome analysis using the Massive Analysis of cDNA Ends (MACE) method. Approximately 9.6% of all genes expressed in leaves are enhanced in response to HS, including a subset of Hsfs and Hsps. The underlying Hsp-Hsf networks with potential functions in stress responses or developmental processes were further explored by meta-analysis of existing microarray datasets. We identified clusters with differential transcript profiles with respect to abiotic stresses, plant organs and developmental stages. The composition of two clusters points toward two major chaperone networks. One cluster consisted of constitutively expressed plastidial chaperones and other genes involved in chloroplast protein homeostasis. The second cluster represents genes strongly induced by heat, drought and salinity stress, including HsfA2 and many stress-inducible chaperones, but also potential targets of HsfA2 not related to protein homeostasis. This observation attributes a central regulatory role to HsfA2 in controlling different aspects of abiotic stress response and tolerance in tomato. 2 samples
2014-08-01 | E-GEOD-56611 | biostudies-arrayexpress
Project description:Heat shock proteins (Hsps) are molecular chaperones primarily involved in maintenance of protein homeostasis. Their function has been best characterized in heat stress (HS) response during which Hsps are transcriptionally controlled by heat stress transcription factors (Hsfs). The role of Hsfs and Hsps in HS-response in tomato was initially examined by transcriptome analysis using the Massive Analysis of cDNA Ends (MACE) method. Approximately 9.6% of all genes expressed in leaves are enhanced in response to HS, including a subset of Hsfs and Hsps. The underlying Hsp-Hsf networks with potential functions in stress responses or developmental processes were further explored by meta-analysis of existing microarray datasets. We identified clusters with differential transcript profiles with respect to abiotic stresses, plant organs and developmental stages. The composition of two clusters points toward two major chaperone networks. One cluster consisted of constitutively expressed plastidial chaperones and other genes involved in chloroplast protein homeostasis. The second cluster represents genes strongly induced by heat, drought and salinity stress, including HsfA2 and many stress-inducible chaperones, but also potential targets of HsfA2 not related to protein homeostasis. This observation attributes a central regulatory role to HsfA2 in controlling different aspects of abiotic stress response and tolerance in tomato.
2014-08-01 | GSE56611 | GEO
Project description:Analysis of transcriptome in moss Physcomitrella patens CNGCb null mutant at 25 and 34 degrees C for 30 minutes. Results provide insight into role of CNGCb in acquired thermotolerance induced by non-lethal heat treatment. Typically at dawn of a hot summer day, land plants need precise molecular thermometers to sense harmless increments in the ambient temperature to timely develop a heat-shock response (HSR) and accumulate protective heat shock proteins (Hsps), in anticipation of upcoming harmful temperatures at mid-day. Here, we found that the CNGCb gene from Physcomitrella patens and its Arabidopsis ortholog CNGC2, encode for a component of cyclic nucleotide gated Ca2+ channels acting as the primary thermosensors of land plant cells. Disruption of CNGCb or CNGC2 produced a hyper-thermosensitive phenotype, giving rise to a HSR and acquired thermotolerance at significantly milder heat-priming treatments than in wild type plants. In an aequorin-expressing moss, CNGCb loss-of-function caused altered Ca2+ signaling and a sustained Ca2+ influx. Patch clamp recordings on moss protoplasts showed the presence of three distinct thermo-responsive Ca2+-channels in wild type cells. Deletion of CNGCb led to a total absence of one, and it increased the open probability of the remaining two thermo-responsive Ca2+ channels. Thus, both in Arabidopsis and moss, CNGC2 and CNGCb are expected to form with other related CNGCs, heteromeric Ca2+ channels in the plasma membrane that respond to mild increments in the ambient temperature by triggering an optimal HSR, leading to the onset of plant acquired thermotolerance.
2012-03-06 | GSE36301 | GEO