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Degradation shaped bacterial and archaeal communities with predictable taxa and their association patterns in Zoige wetland at Tibet plateau
No full textSoil microbes provide important ecosystem services. Zoige Plateau wetland, the largest alpine peat wetland in the world, has suffered from serious degradation in the past 30 years. We studied the composition of the Zoige Plateau alpine wetland soil microbiota and relations among specific taxa using 16S rRNA amplicon sequencing combined with association network analysis. Compared to the pristine swamp soil, taxons DA101, Aeromicrobium, Bradyrhizobium, and Candidatus Nitrososphaera were enriched and several methanogenic Euryarchaeota were depleted in the moderately degraded meadow soil and highly degraded sandy soil. Soil total potassium contents in soils with different degradation levels were significantly different, being the highest in meadow soil and lowest in swamp soil. The association network analysis showed that total potassium positively correlated with specific bacterial and archaeal taxa. Jiangella, Anaerolinea, Desulfobulbus, Geobacter, Flavobacterium, Methanobacterium and Methanosaeta were identified as the keystone genera in the networks. Soil degradation affected soil properties, and caused changes in the bacterial and archaeal community composition and the association patterns of community members. The changes could serve as early warning signals of soil degradation in alpine wetlands
Environmental factors driving fungal distribution in freshwater lake sediments across the Headwater Region of the Yellow River, China
No full textDispersal limitation and environmental filtering are two primary processes involved in shaping microbial community structure. The pristine environmental and geographical relatively isolation of small lakes distributed in the Headwater Region of Yellow River (HRYR) offer a unique opportunity to test the relative roles of these two processes on fungal communities. Here, we investigated the fungal community in sediment samples from 10 lakes located in the HRYR using high-throughput sequencing. The results showed that the fungal community was dominated by Sordariomycetes, Leotiomycetes, Dothideomycetes, Pezizomycetes and Agaricomycetes. The results revealed that altitude, mean annual temperature, C/N ration, dissolve organic carbon and total nitrogen were the best predictors for shaping fungal community structure in these lakes. Significant spatial and environmental distance decay relationships in the fungal community were detected. The partial Mantel test indicated that the fungal community structure was significantly correlated with environmental distance but not with geographic distance. Overall, environmental filtering plays a more important role than dispersal limitation in fungal community structure at a local scale in such an pristine and isolated region
Metagenomic analysis of microbial community and function involved in cd-contaminated soil
No full textBackground: Soil contaminated with the heavy metal Cadmium (Cd) is a widespread problem in many parts of the world. Based on metagenomic analysis, we investigated the functional potential and structural diversity of the microbial community in Cd-contaminated and non-contaminated soil samples and we explored the associated metabolic pathway network in cluster of orthologous groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Results: The results showed that microorganisms in these soils were quite abundant, and many of them possessed numerous physiological functions. However, Cd-contamination has the potential to reduce the microbial diversity and further alter the community structure in the soil. Notably, function analysis of the crucial microorganisms (e.g. Proteobacteria, Sulfuricella and Thiobacillus) indicated that these bacteria and their corresponding physiological functions were important for the community to cope with Cd pollution. The COG annotation demonstrated that the predominant category was the microbial metabolism cluster in both soil samples, while the relative abundance of metabolic genes was increased in the Cd-contaminated soil. The KEGG annotation results exhibited that the non-contaminated soil had more genes, pathways, modules, orthologies and enzymes involved in metabolic pathways of microbial communities than the Cd-contaminated soil. The relative abundance of some dominant KEGG pathways increased in the Cd contaminated soil, and they were mostly enriched to the metabolism, biosynthesis and degradation of amino acids, fatty acids and nucleotides, which was related to Cd tolerance of the microorganisms. Conclusions: Cd-contamination can decrease the taxonomic species of microbes in soil and change the soil microbial composition. The functional pathways involved in the soil change with microbial structure variation, many of which are related to the heavy metal tolerance of soil microbes. The Cd-contaminated soil microbes is a potential resource for exploring cadmium resistant or tolerant bacteria
Delaying chloroplast turnover increases water-deficit stress tolerance through the enhancement of nitrogen assimilation in rice
No full textAbiotic stress-induced senescence in crops is a process particularly affecting the photosynthetic apparatus, decreasing photosynthetic activity and inducing chloroplast degradation. A pathway for stress-induced chloroplast degradation that involves the CHLOROPLAST VESICULATION (CV) gene was characterized in rice (Oryza sativa) plants. OsCV expression was up-regulated with the age of the plants and when plants were exposed to water-deficit conditions. The down-regulation of OsCV expression contributed to the maintenance of the chloroplast integrity under stress. OsCV-silenced plants displayed enhanced source fitness (i.e. carbon and nitrogen assimilation) and photorespiration, leading to water-deficit stress tolerance. Co-immunoprecipitation, intracellular co-localization, and bimolecular fluorescence demonstrated the in vivo interaction between OsCV and chloroplastic glutamine synthetase (OsGS2), affecting source-sink relationships of the plants under stress. Our results would indicate that the OsCV-mediated chloroplast degradation pathway is involved in the regulation of nitrogen assimilation during stress-induced plant senescence
Remediation of hydrocarbon-heavy metal co-contaminated soil by electrokinetics combined with biostimulation
No full textSuccessful remediation of organics and heavy metals compound pollution is challenging, and their removal using conventional techniques is often difficult. This study developed an enhanced electrokinetics technology to decontaminate a hydrocarbon-heavy metal co-contaminated soil by applying biostimulation and selective membranes (cationic and anionic). A 30-day experiment was conducted in the laboratory to remediate the soil co-contaminated with total petroleum hydrocarbon (TPH) (9075 mg/kg) and Ni (446.6 mg/kg). The results demonstrated that the addition of anion-and cation-exchange membranes maintained soil pH stability. BioEK remediation under pH control improved microbial growth, microbial degradation of petroleum and reduced biological toxicity. Microbial action immobilized metals (e.g., reduction in exchangeable Ni and the increase in residual Ni). The degradation rate of TPH in contaminated soil was linearly correlated with the increase in TPH degradation population (P < 0.05). Under the optimum operating conditions, electro-bioremediation achieved 77.4% TPH degradation and 58.5% Ni removal after 30 days. Thus, the application of EK with the use of anion-and cation-exchange membranes improved microbial growth and biodegradation, and indigenous bacteria could effectively reduce metal toxicity. The proposed technique can effectively remediate the soil contaminated by heavy metal and organic pollutants
Inhibition of TPL2 by interferon- suppresses bladder cancer through activation of PDE4D
No full textBackgroundDrugs that inhibit the MEK/ERK pathway have therapeutic benefit in bladder cancer treatment but responses vary with patients, for reasons that are still not very clear. Interferon- (IFN-) is also used as a therapeutic agent for bladder cancer treatment but the response rate is low. It was found that IFN- could enhance the cytotoxic effect of MEK inhibition. However, the potential mechanisms of that are still unclear. Understanding of the cross-talk between the IFN- and MEK/ERK pathway will help enhance the efficacy of IFN- or MEK inhibitors on bladder cancer.MethodsImmunoprecipitation and pull-down assay were used to reveal the formation of signaling complex. The protein expressions were detected by western blot and immunohistochemistry. The cAMP level, Phosphodiesterase 4D (PDE4D) activity and Prostaglandin E-2 (PGE(2)) concentration in cells, serum and tissues were detected by enzyme-linked immunosorbent assay. The role of PDE4D in bladder tumorigenesis in vivo was examined by the xenograft model. Tissue microarray chips were used to investigate the prognostic roles of PDE4D and tumor progression locus 2 (TPL2) in bladder cancer patients.ResultsIFN- down-regulated the cyclooxygenase-2 (COX-2) expression in bladder cancer cells through the inhibition of TPL2/NF-B pathway; IFN- also inhibited COX-2 expression by suppressing cAMP signaling through TPL2-ERK mediated PDE4D activity. Reduction of the intracellular cAMP level by PDE4D potentiated the antitumor effect of IFN- against bladder cancer in vitro and in vivo. Further analysis of clinical samples indicated that low PDE4D expression and high level of TPL2 phosphorylation were correlated to the development and poor prognosis in bladder cancer patients.ConclusionsOur data reveal that IFN- can exert its antitumor effect through a non-canonical JAK-STAT pathway in the bladder cancer cells with low activity of IFN pathway, and the TPL2 inhibition is another function of IFN- in the context of bladder cancer therapy. The antitumor effects of IFN- and MEK inhibition also depend on the PDE4D-mediated cAMP level in bladder cancer cells. Suppression of the TPL2 phosphorylation and intracellular cAMP level may be possible therapeutic strategies for enhancing the effectiveness of IFN- and MEK inhibitors in bladder cancer treatment
A efficient method to identify cardioprotective components of Astragali Radix using a combination of molecularly imprinted polymers-based knockout extract and activity evaluation
No full textAlthough herb medicines have become the major source for new drug discovery, many of them are largely under-explored due to the purity-activity relationship. Efficient identification of bioactive compounds in conventional stepwise separation and isolation has not yet been elucidated. Therefore, we proposed a new separation strategy for holism understanding of herb pharmacology using molecularly imprinted polymers (MIPs). Astragali Radix (AR), important in traditional Chinese medicine, was chosen in this study for multicomponent knockout followed by bioactivity evaluation. We prepared calycosin molecularly imprinted polymers (calycosin-MIPs) which could selectively recognize flavonoid aglycons in AR. The molecular selectivity of calycosin-MIPs as a critical parameter was evaluated using the template and other high content compounds in AR. Based on it, using the calycosin-MIPs material via solid-phase extraction procedures was applied for the knockout of flavonoid aglycons in AR. Finally, hypoxia/reoxygenation model in H9c2 cells was used to evaluate the activity of the AR extract before and after knockout. The results showed that calycosin-MIPs as recognition materials for flavonoid aglycons in AR are applied in one-step separation with high selectivity and tunability. The subextract in the absence of flavonoid aglycons has been demonstrated to clarify the cardio-protective components of AR. In conclusion, this proof-of-principle study is the first one showing that molecular imprinting technology coupled with a bioassay can be used to explore the bioactive variability from the perspective of multicomponent separation of herbal medicine. (C) 2018 Elsevier B.V. All rights reserved
A novel PAX7 10-bp indel variant modulates promoter activity, gene expression and contributes to different phenotypes of Chinese cattle
No full textPaired box 7 (PAX7) gene regulates the conversion of muscle satellite cells into myogenic cells and participates in multi-step processes in myogenesis. Expression levels of PAX7 are decisive for its regulatory function. Previous reports revealed that PAX7 were responsible for the developmental traits of muscle. The relationship of the PAX7 promoter variants and livestock phenotypic traits has not been fully elucidated. We detected a novel 10-bp insertion/deletion (indel) polymorphism in the bovine PAX7 promoter and revealed that the indel altered the binding of the transcriptional factor ZNF219. Luciferase reporter assay showed that deletion-deletion (Del-Del) genotype of the PAX7 gene showed 2.79-fold higher promoter activity than the insertion-insertion (Ins-Ins) genotype (P < 0.05), and ZNF219 overexpression significantly diminished the luciferase activity in Ins-Ins groups. Moreover, the expression of PAX7 and its down-stream genes were detected in fetal skeletal muscle of cattle with different PAX7 genotypes, where the Del-Del genotype also displayed high expression levels. Statistical association analysis demonstrated that this indel had significant effects on early growth traits in cattle. These findings provide a complete overview of the function of the PAX7 10-bp variant, which may have potential as a genetic marker for marker-assisted selection in improving economically significant traits of cattle
Three new species of the fern genus Arachniodes (Dryopteridaceae) from Vietnam
No full textThree new species of the fern genus Arachniodes (Dryopteridaceae) are described from Vietnam: A. daklakensis, A. longicaudata, and A. quangnamensis. The first two occur in Central Highlands and Central Vietnam, respectively, while the last is found in the north (Bavi, Langson and Tamdao) as well as in the central Vietnam (Nghean, Quangbinh, Quangtri)
Thiourea-catalyzed asymmetric domino Michael-cyclization reaction of 3-isothiocyanato oxindoles with beta,gamma-unsaturated alpha-keto esters for the synthesis of spirocyclic oxindoles
No full textA reaction between 3-isothiocyanato oxindoles and beta,gamma-unsaturated alpha-keto esters catalyzed by a chiral thiourea organocatalyst via a domino Michael-cyclization process is described, which delivers a range of biologically important 2'-thioxospiro[indoline-3,4'-oxazolidin]-2-one compounds in high yields with good diastereo- and enantioselectivities (up to 99% yield, >99:1 dr, >99% ee). Moreover, two of 2'-thioxospiro[indoline-3,4'-oxazolidin]-2-one compounds were found to significantly behave in antiinflammatory activities in a preliminary biological evaluation. (C) 2019 Published by Elsevier Ltd