Project description:Soil transplant serves as a proxy to simulate climate change in realistic climate regimes. Here, we assessed the effects of climate warming and cooling on soil microbial communities, which are key drivers in Earth’s biogeochemical cycles, four years after soil transplant over large transects from northern (N site) to central (NC site) and southern China (NS site) and vice versa. Four years after soil transplant, soil nitrogen components, microbial biomass, community phylogenetic and functional structures were altered. Microbial functional diversity, measured by a metagenomic tool named GeoChip, and phylogenetic diversity are increased with temperature, while microbial biomass were similar or decreased. Nevertheless, the effects of climate change was overridden by maize cropping, underscoring the need to disentangle them in research. Mantel tests and canonical correspondence analysis (CCA) demonstrated that vegetation, climatic factors (e.g., temperature and precipitation), soil nitrogen components and CO2 efflux were significantly correlated to the microbial community composition. Further investigation unveiled strong correlations between carbon cycling genes and CO2 efflux in bare soil but not cropped soil, and between nitrogen cycling genes and nitrification, which provides mechanistic understanding of these microbe-mediated processes and empowers an interesting possibility of incorporating bacterial gene abundance in greenhouse gas emission modeling.
Project description:Soil transplant serves as a proxy to simulate climate change in realistic climate regimes. Here, we assessed the effects of climate warming and cooling on soil microbial communities, which are key drivers in EarthM-bM-^@M-^Ys biogeochemical cycles, four years after soil transplant over large transects from northern (N site) to central (NC site) and southern China (NS site) and vice versa. Four years after soil transplant, soil nitrogen components, microbial biomass, community phylogenetic and functional structures were altered. Microbial functional diversity, measured by a metagenomic tool named GeoChip, and phylogenetic diversity are increased with temperature, while microbial biomass were similar or decreased. Nevertheless, the effects of climate change was overridden by maize cropping, underscoring the need to disentangle them in research. Mantel tests and canonical correspondence analysis (CCA) demonstrated that vegetation, climatic factors (e.g., temperature and precipitation), soil nitrogen components and CO2 efflux were significantly correlated to the microbial community composition. Further investigation unveiled strong correlations between carbon cycling genes and CO2 efflux in bare soil but not cropped soil, and between nitrogen cycling genes and nitrification, which provides mechanistic understanding of these microbe-mediated processes and empowers an interesting possibility of incorporating bacterial gene abundance in greenhouse gas emission modeling. Fifty four samples were collected from three soil types (Phaeozem,Cambisol,Acrisol) in three sites (Hailun, Fengqiu and Yingtan) along a latitude with reciprocal transplant; Both with and without maize cropping in each site; Three replicates in every treatments.
Project description:Microgravity is known to affect the organization of the cytoskeleton, cell and nuclear morphology and to elicit differential expression of genes associated with the cytoskeleton, focal adhesions and the extracellular matrix. Although the nucleus is mechanically connected to the cytoskeleton through the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex, the role of this group of proteins in these responses to microgravity has yet to be defined. Therefore, we used simulated microgravity achieved by growing cells on a 3d clinostat to investigate whether the LINC complex acts to mediate responses to the microgravity environment. We show that nuclear shape and differential gene expression are both responsive to simulated microgravity in a LINC-dependent manner and that this response changes with the duration of exposure to simulated microgravity. These LINC-dependent genes likely represent elements normally regulated by the mechanical forces imposed by gravity on Earth.
Project description:Grapevines cv Sauvignon Blanc were subjected to different stress regimes by simulating the most common extreme weather events occurring within the current climate change scenario. During spring, just before bud break, the vines were either flooded or kept under normal conditions. Both vines were then split in two groups and put in differnt tunnels, either undergoing a simulated heatwave or not. Berry samples were collected from the four groups of plants (control, only flooded, only heatwave, flooded + heatwave) at different timepoints before, during and after the stress. Transcriptomic analyses were carried out on these samples along with some metabolomic assessments to characterize the response to stress in the different samples and the effect of the combined stresses.
Project description:Astronauts have been previously shown to exhibit decreased salivary lysozyme and increased dental calculus and gingival inflammation in response to space flight, host factors that could contribute to oral diseases such as caries and periodontitis. However, the specific physiological response of caries-causing bacteria such as Streptococcus mutans to space flight and/or ground-based simulated microgravity has not been extensively investigated. In this study, High Aspect Ratio Vessel (HARV) S. mutans simulated microgravity and normal gravity cultures were assessed for changes in metabolite and transcriptome profiles, H2O2 resistance, and competence in sucrose-containing biofilm media. Stationary phase S. mutans simulated microgravity cultures displayed increased killing by H2O2 compared to normal gravity control cultures, but competence was not affected. RNA-seq analysis revealed that expression of 153 genes was up-regulated ≥ 2-fold and 94 genes down-regulated ≥ 2-fold during simulated microgravity HARV growth. These included a number of genes located on extrachromosomal elements, as well as genes involved in carbohydrate metabolism, translation, and stress responses. Collectively, these results suggest that growth under microgravity analog conditions promotes changes in S. mutans gene expression and physiology that may translate to an altered cariogenic potential of this organism during space flight missions.
Project description:Directional selection in the domestication of fish species has resulted in rapid gains of growth, body size, and other production-relevant traits in relatively few generations. While there is clear evidence of genetic divergence contributing to selection-related phenotypic changes, emerging research suggests that intergenerational epigenetic inheritance may also be a relevant mechanism explaining rapid evolutionary change in domestic fish lines. Epigenetic changes have also been implicated in fish species’ responses to warming associated with climate change. Domestic lines of Brook Charr (Salvelinus fontinalis) are the primary source of fish used for recreational fisheries stocking in many parts of Eastern North America and there are concerns about how these fish will fare when stocked into lakes in the coming decades. We jointly investigated the effects of directional selection for performance traits (i.e., absence of early sexual maturation and increased growth) and exposure to elevated temperatures on DNA methylation in sperm cells of two experimental lines (hereafter: Selected and Control lines) of Brook Charr . We used whole-genome bisulfite sequencing to characterize DNA methylation at over 17 million methylated sites and identified 393 selection-related differentially methylated regions (DMR). The putative functions of genes in proximity to these DMRs are consistent with well-characterized phenotypic differences between the lines, including lipid metabolism and precocial maturation, and support the hypothesis that rapid evolution of traits may be partially mediated by epigenetic inheritance. We subsequently detected 85 warming-related DMRs in the Control line and 302 DMRs in the Selected line. None of these regions were shared between the two lines, indicating that the directional selection regime significantly altered the environmentally sensitive epigenetic landscape.