Project description:Heat stress is the primary obstacle for landscape application of azalea in hot-summer areas. Heat acclimation can confer acquired thermotolerance to R. hainanense even after a long recovery. The mechanisms and key factors involved in the heat acclimation memory were investigated.
Project description:Heat acclimation (AC) allows its faster re-induction following its decline. Constitutively preserved euchromatin state in hsp70 promoter during acclimation decline/regain pushed forward the hypothesis that acclimation decline is a period of “dormant memory” involving molecular program including epigenetic controlled transcriptional regulation leading to heat acclimation mediated cytoprotective memory. We used microarray to uncover hallmark pathways in the induction of heat-acclimation-mediated memory, focusing on markers of epigenetic processes.
Project description:Heat acclimation (AC) allows its faster re-induction following its decline. Constitutively preserved euchromatin state in hsp70 promoter during acclimation decline/regain pushed forward the hypothesis that acclimation decline is a period of M-bM-^@M-^\dormant memoryM-bM-^@M-^] involving molecular program including epigenetic controlled transcriptional regulation leading to heat acclimation mediated cytoprotective memory. We used microarray to uncover hallmark pathways in the induction of heat-acclimation-mediated memory, focusing on markers of epigenetic processes. Rats subjected to heat acclimation, deacclimation, reacclimation and untreated controls were used. We showed here that (i) AC2d provides the molecular switch for acclimation (ii) AC30 heart demonstrates qualitative adaptations (iii) specific molecular program encompassing up/down regulated gene during DeAC, of which epigenetic markers such as class A histones, chromatin modifiers and microRNA suggest epigenetic transcriptional regulation linked to acclimation memory (iv) constitutive upregulation of MAPK P38 module and targets as well as jak/stat and AKT associated pathways during DeAC imply its major role in this process. Noteworthy are players such as poly-(ADP-ribose)polymerase-1 (PARP1) and linker histones (histones H1 cluster in this process).
Project description:Abiotic stress is a major factor for crop productivity, a problem likely to be exacerbated by climate change. Improving the tolerance to environmental stress is one of the most important goals of crop breeding programmes. While the early responses to abiotic stress in plants are well studied, plant adaptation to enduring or recurring stress conditions has received little attention. This project investigates the molecular mechanism of the maintenance of acquired thermotolerance as a model case of stress memory in Arabidopsis. Arabidopsis seedlings acquire thermotolerance through a heat treatment at sublethal temperatures. To investigate the underlying mechanisms, we are investigating changes in the transcriptome at two timepoints after a heat acclimation treatment using Arabidopsis thaliana seedlings. Microarrays were used to compare gene expression at two timepoints after a heat acclimation treatment.
Project description:Abiotic stress is a major factor for crop productivity, a problem likely to be exacerbated by climate change. Improving the tolerance to environmental stress is one of the most important goals of crop breeding programmes. While the early responses to abiotic stress in plants are well studied, plant adaptation to enduring or recurring stress conditions has received little attention. This project investigates the molecular mechanism of the maintenance of acquired thermotolerance as a model case of stress memory in Arabidopsis. Arabidopsis seedlings acquire thermotolerance through a heat treatment at sublethal temperatures. To investigate the underlying mechanisms, we are investigating changes in the transcriptome at two timepoints after a heat acclimation treatment using Arabidopsis thaliana seedlings. Microarrays were used to compare gene expression at two timepoints after a heat acclimation treatment.
Project description:We compared two groups of abalones (from the same population) with different temperature acclimation history, through their survival at acute heat treatment and metabolites changes. The results indicated significantly higher survival for the high temperature acclimation group. Both groups experienced mitochondrial homeostasis break down during heat treatment, while the higher temperature acclimation group accumulated more metabolites beneficial to metabolic homeostasis, including various dipeptides, antioxidants, and neuroprotective substances.
Project description:Heat waves caused by global warming severely challenge photosynthesis and hence plant biomass production, but the mechanisms of its adjustment, repair and biogenesis during heat acclimation are elusive. We provide a global and time-resolved insight, how these processes are modulated during heat acclimation in chloroplasts, revealing profound modulation of protein biogenesis. Ribosome profiling with Chlamydomonas reinhardtii showed early translational downregulation during synthesis of photosynthesis core antenna proteins, a response that is conserved in Nicotiana tabacum. Our data suggest that these early effects may be caused by reduced translocation of ribosomes synthesizing thylakoid proteins, and that later heat acclimation alleviates these effects. Analysis of the proteinaceous interactome of plastid ribosomes demonstrates widespread remodeling of ribosome-associated processes that could be responsible for the early translational impacts and subsequent acclimation responses. The role of chlorophyll metabolism, protein targeting, and assembly of photosystem complexes as co-translational bottlenecks during heat acclimation are discussed.
Project description:The processes of adaptation to environmental heat and aerobic exercise training improve efficiency in various body systems and bring about acclimatory homeostasis. In order to examine the global genomic responses of the soleus and heart following exposure of rats to these stressors, nylon cDNA Atlas Array was used. Male rats were exposed to one of the following stressors: heat acclimation, aerobic training (treadmill), and combined heat acclimation and aerobic training for short (2, 3 days) and long (1 mo) time period. The study comprised seven experimental groups: Controls-untreated. Heat acclimated groups (2dac, Acc)â exposure to environmental heat at 34C for 2 or 30 days. Exercise groups (3dex, Ex)â graduated training protocol under normothermic conditions for 3 and 30 days at 24C. Exercise training and heat acclimation â (3dexac, ExAc)- exposed to both environmental heat and aerobic exercise as above. The Series data tables appended below: 1) Heart - normalized log2 ratio of geomeans defined as treatment/control 2) Soleus - normalized log2 ratio of geomeans defined as treatment/control 21 samples, 3 pool each, of: 1)Â Control untreated rats 2)Â Long-term heat acclimated rats 3)Â Long-term aerobic-exercised trained rats. 4)Â Rats exposed to long-term heat acclimation and exercise training. 5)Â Short term heat acclimated rats. 6)Â Short term aerobic exercised trained rats 7)Â Rats exposed to short-term heat acclimation and exercise training.
Project description:We studied the global genomic response in the hypothalamus during heat acclimation, with and without combined hypohydration stress. Rats were acclimated for 2 days or for 30 days at 34°C. Hypohydration (10% decrease in body weight) was attained by water deprivation. Functional analyses demonstrated a bi-phasic acclimatory profile with a transient upregulation of genes encoding ion channels, transporters, and transmitter signaling upon 2 days acclimation, suggesting enhanced neuronal excitability at that acclimation phase. Following long acclimation most genes returned to their pre-acclimation expression levels. In both acclimation phases, genes encoding hormones and neuropeptides, linked with metabolic rate and food intake, were downregulated. The response to hypohydration was characterized by an upregulation of a large number of genes primarily associated with the regulation of ion channels and cell-volume and neuronal excitability. During 2 days acclimation, the response was transiently desensitized, recovering upon LTHA. The results suggest that hypohydration overrides the heat acclimatory status. Keywords: other