Abstract Background Soil fungi play crucial roles in ecosystem functions. However, how snow cover change associated with winter warming affects soil fungal communities remains unclear in the Tibetan forest. Methods We conducted a snow manipulation experiment to explore immediate and legacy effects of snow exclusion on soil fungal community diversity and composition in a spruce forest on the eastern Tibetan Plateau. Soil fungal communities were performed by the high throughput sequencing of gene-fragments. Results Ascomycota and Basidiomycota were the two dominant fungal phyla and Archaeorhizomyces , Aspergillus and Amanita were the three most common genera across seasons and snow manipulations. Snow exclusion did not affect the diversity and structure of soil fungal community in both snow-covered and snow-free seasons. However, the relative abundance of some fungal communities was different among seasons. Soil fungal groups were correlated with environmental factors (i.e., temperature and moisture) and soil biochemical variables (i.e., ammonium and enzyme). Conclusions These results suggest that the season-driven variations had stronger impacts on soil fungal community than short-term snow cover change. Such findings may have important implications for soil microbial processes in Tibetan forests experiencing significant decreases in snowfall.
Abstract Background: Soil fungi play crucial roles in ecosystem functions. However, how snow cover change associated with winter warming affects soil fungal communities remains unclear in the Tibetan forest. Methods: We conducted a snow manipulation experiment to explore immediate and legacy effects of snow exclusion on soil fungal community diversity and composition in a spruce forest on the eastern Tibetan Plateau. Soil fungal communities were performed by the high throughput sequencing of gene-fragments. Results: Ascomycota and Basidiomycota were the two dominant fungal phyla and Archaeorhizomyces , Aspergillus and Amanita were the three most common genera across seasons and snow manipulations. Snow exclusion did not affect the diversity and structure of soil fungal community in both snow-covered and snow-free seasons. However, the relative abundance of some fungal communities was different among seasons. Soil fungal groups were correlated with environmental factors (i.e., temperature and moisture) and soil biochemical variables (i.e., ammonium and enzyme). Conclusions: These results suggest that the season-driven variations had stronger impacts on soil fungal community than short-term snow cover change. Such findings may have important implications for soil microbial processes in Tibetan forests experiencing significant decreases in snowfall.
The Cre recombinase from bacteriophage P1 can recognize specific DNA sequences, cleave DNA at specific target sites, and then ligate it to the cleaved DNA of a second site. In this study, cre gene was cloned into the pGEM-T Easy vector via PCR procedure. Then the cre gene was inserted into an expression vector pET-29a and expressed in E. coli BL21 (DE3). A 38 kD soluble protein was expressed and named CRE. CRE was purified by DEAE-52 chromatography. Bioassay of the partially purified product showed that CRE can cleave the plasmid pGLGFP which contains two loxP site with the same direction.
Introduction: Loss of skin integrity due to a wound or disease can lead to severe disability or even life threat. The highly expressed microRNAs in the skin are of great significance for skin development. The investigation purposed to explore the effect and mechanism of miR-211 on inflammation, oxidative stress and migration in keratinocytes. Methods: The HaCaT keratinocytes were treated with hydrogen peroxide (H2O2) to establish a wound-healing model. The expression of miR-211 was examined by quantitative real-time PCR (qRT-PCR). The cell function was reflected in proliferative ability, migration, apoptosis, and inflammation, which were evaluated by Cell Counting Kit-8 (CCK-8) assay, Transwell test, flow cytometry technique, and enzyme-linked immunosorbent assay (ELISA). The target of miR-211 was verified by luciferase luminescence measurements. Results: H2O2 inhibited HaCaT cell proliferation, migration, and promoted cell apoptosis, accompanied with the downregulation of miR-211. H2O2 led to inflammatory response and oxidative damage to HaCaT. MiR-211 promoted proliferation and migration, but improved cell apoptosis of HaCaT. The role of H2O2 on inflammatory response and oxidative stress was alleviated by miR-211. SRY-box transcription factor 11 (SOX11) was a targeted mediator of miR-211. SOX11 reversed the influence of miR-211 on cell proliferation, migration, apoptosis, inflammatory response and oxidative stress. Conclusion: MiR-211 regulated proliferation, migration, apoptosis, inflammation and oxidative stress of keratinocytes by mediating SOX11, thus participating in cutaneous wound healing.
With the development of marine economy and climate changing, the ecological value of mangrove ecosystem has become increasingly prominent. In this study, the ecological values of China’s mangrove ecosystem services was evaluated based on the four services and nine functions of mangrove ecosystem. On this basis, the dynamic changing characteristics of the nine mangrove ecological values from 2001 to 2019 were analyzed. The results indicated that the top four service values were that of preventing coastal erosion, raw material supply, regulating water resources, and regulating climate and maintaining air quality. Significant changes were found in China’s mangrove areas which increased during 2001–2013 and decreased during 2013–2019, while the unit area value of mangrove ecosystem services generally showed an upward trend. Subsequently, the evaluation results were applied to mangrove asset management with balance sheets, ecological compensation standard determination, and carbon trading in blue carbon sink. Based on the above analysis, the corresponding countermeasures and suggestions were proposed for mangrove protection and value application to guide effective management on mangroves and further to realize a higher ecological value of mangrove ecosystem.
Three minitype subsurface-horizontal flow constructed wetlands planted with Calamagrostis angustifolia and Phragmites australis and filled with soil and slag were used to investigate the N, P and pH for upper layer and underlayer wetland system by intermission operation. Results demonstrated that TN removal rates in the superstratum of Calamagrostis angustifolia and Phragmites australis wetlands were 0.771 g x (m2 x d)(-1), 1.481 g x(m2 x d)(-1) with 10 days of the hydraulic retention, which were 1.15 and 1.31 times higher than that of underlayer wetland systems, respectively. Simultaneity, TP removal rates in the superstratum of Calamagrostis angustifolia and Phragmites australis wetlands were 1.655 g x (m2 x d)(-1), 6.838 g x (m2 x d)(-1), respectively, which were 1.13 and 1.28 times higher than that of underlayer wetland systems, respectively. The purification ability of upper layer in the wetland system was higher than that of underlayer. A regular trend of pH changes and upstanding buffer ability of wetland system were found. The pH values in the upper layer of soil-slag wetlands were smaller than that of underlayer which was contrary to the soil wetland. The break-point of pH curve indicates the termination of NH4(+) -N reaction in constructed wetland.
In autumn 2008, a total of 65 plough layer soil samples were collected from the paddy fields in Qianguo Irrigation Area located at the downstream of the Second Songhua River. These paddy fields were irrigated with water from the River, and had different irrigation histories. The Cu, Pb, Zn, Cd, Ni, As, and Hg concentrations in the soil samples were determined, and the accumulation characteristics, input approaches, and pollution sources of these heavy metals were analyzed. The Cu, Pb, Zn, Cd, Ni, As, and Hg concentrations in the samples were 14.1-28.4 mg x kg(-1), 37.6-57.4 mg x kg(-1), 53.3-84.4 mg x kg(-1), 0.044-0.367 mg x kg(-1), 18.4-37.0 mg x kg(-1), 3.25-12.11 mg x kg(-1), and 0.031-0.155 mg x kg(-1), respectively. The Pb, Hg, and Cd exhibited an obvious accumulation trend, with their concentrations being 100.0%, 38.7%, and 66.1% higher than the baselines, respectively, while Cu, Zn, Ni, and As had less accumulation. With the increase of irrigation history, the Pb concentration showed a decreasing trend, while the Hg concentration was in reverse. There was no significant correlation between the Cd concentration and the irrigation history. According to source analysis, soil Pb mainly originated from the atmospheric Pb deposition via historical use of leaded gasoline, soil Hg was from the polluted irrigation water from the Second Songhua River, and soil Cd was from the use of chemical fertilizers, pesticides, and other agrochemicals. Though the Pb, Hg, and Cd had obviously accumulated in the paddy fields in Qianguo Irrigation Area, their potential ecological risk was still low, and would not pose threat on the local agricultural production and food security.
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