Project description:Here we use a transcriptomic approach to investigate the molecular underpinnings of thermal stress in the model cyanobacteria species Synechocystis. We impose gradual heat stress by increasing the temperature in a stepwise fashion (1.5 °C h-1) from their optimal growth temperature of 30 °C to a maximum temperature of 46.5 °C over a period of 12h.
Project description:High temperature is increasingly becoming one of the prominent environmental factors affecting the growth and development of maize (Zea mays L.). Therefore, it is critical to identify key genes and pathways related to heat stress (HS) tolerance in maize. Here, we identified a heat-resistant (Z58D) and heat-sensitive (AF171) maize inbred lines at seedling stage. Transcriptomic analysis identified 3,006 differentially expressed genes (DEGs) in AF171 and 4,273 DEGs in Z58D under HS treatments, respectively. Subsequently, GO enrichment analysis showed that shared upregulated genes in AF171 and Z58D involved in response to HS, protein folding, abiotic and temperature stimulus pathway. Moreover, the comparison between the two inbred lines under HS showed that response to heat and response to temperature stimulus significantly overrepresented for the 1,234 upregulated genes. Furthermore, commonly upregulated genes in Z58D and AF171 had higher expression level in Z58D than AF171. In addition, maize inbred CIMBL55 had been verified to be more tolerant than B73 and commonly upregulated genes had higher expression level in CIMBL55 than B73 under HS. The consistent results indicated that heat-resistant inbred lines may coordinate the remarkable expression of genes in order to recover from HS. Additionally, 35 DEGs were conserved among 5 inbred lines by a comparative transcriptomic analysis. Most of them were more pronounced in Z58D than AF171 at expression level. Those candidate genes may confer thermotolerance in maize.
Project description:Transcriptional profiling of the digestive gland tissue of female mussel Mytilus galloprovincialis exposed to nickel along with a temperature gradient Background: The exposure of marine organisms to stressing agents may affect the level and pattern of gene expression. Although many studies have examined the ecological effects of heat stress on mussels, little is known about the physiological mechanisms that might be affected by co-exposure to heat stress and environmental contaminants such as nickel (Ni). In the present work we investigated the effects of simultaneous changes in temperature and Ni supply on lysosomal membrane stability (LMS) and malondialdehyde accumulation (MDA) in the digestive gland (DG) of the blue mussel Mytilus galloprovincialis (Lam.). To shed some light into how the molecular response to environmental stressors is modulated, we employed a cDNA microarray with 1,673 sequences to measure the relative transcript abundances in the DG of mussels exposed to Ni along with the temperature increase. Temperature and Ni rendered additive effects on LMS and MDA accumulation, increasing the toxic effects of metal cations. Ni loads in DG tissues was also affected by co-exposure to 26°C. In animals exposed only to heat stress, functional genomics analysis of the microarray data (171 DEGs) revealed 7 biological processes, largely dominated by the up-regulation of folding protein-related genes, and the down regulation of genes involved in cell migration and cellular component assembly. Exposure to Ni at 18°C and 26°C rendered respectively 188 and 262 DEGs showing distinct pattern in term of biological processes. In particular, the response of mussels exposed to Ni at 26°C was characterized by the up regulation of proteolysis, ribosome biogenesis, response to unfolded proteins and catabolic-related genes as well as the down-regulation of genes encoding cellular metabolic processes. Our data provide new insights on the transcriptomic response in mussels challenging temperature increases and Ni exposure and should be carefully considered in view of the biological effects of heat stress and particularly in polluted areas.
Project description:We designed an experimental setup to investigate the transcriptomic and proteomic responses of the hyperthermophilic archaeon Pyrococcus furiosus to heat and cold shock. P. furiosus is a model organism for studying microbial adaptation to extreme environments, including deep-sea hydrothermal vents with temperature gradients ranging from 1°C to 400°C. We aimed to simulate critical conditions where P. furiosus cannot grow and to examine the immediate response to thermal stress as well as the recovery process.
Project description:Plants transcriptome react to environment temperature changes profoundly. In Arabidopsis seedlings, genes respond to temperature fluctuations to adopt the ever-changing ambient environment. We used microarrays to detail the global programme of gene expression underlying heat stress response progress in Arabidopsis.
Project description:Jujube (Ziziphus jujuba Mill.) is an economically and agriculturally significant fruit crop and is widely cultivated throughout the world. Heat stress has recently become one of the major abiotic stresses limiting plant growth and productivity. However, there are few studies on the transcriptome profiling of jujube subjected to heat stress. In this study, we analyzed the physiological and transcriptomic changes of heat-resistant jujube cultivar ‘HR’ and heat-sensitive cultivar ‘HS’ caused by high temperature stress. We statistically determined 984, 1468, 1727 and 2098 differentially expressed genes (DEGs) between ‘HR’ and ‘HS’ after 0, 1, 3, 5 d of heat stress, respectively. Gene Ontology (GO) enrichment analysis indicated that Aa great deal of heat-responsive genes were identified in these DEGs by Gene Ontology (GO) enrichment analysis. It suggests the distinct molecular mechanism of jujube response to heat stress. Furthermore, we validated the expression profiles of 12 candidates using qRT-PCR to further confirm the accuracy of the RNA-seq data. These results will advance our knowledge of the genes involved in the complex regulatory networks of heat stress and provide genetic resources for further improving the heat tolerance in jujube.
Project description:High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, we employed a microarray analysis with silique walls and seeds from the developing siliques (20 days after flowering) of Brassica napus that had undergone heat stress.