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1.
Environ Res ; 263(Pt 1): 120030, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39299450

RESUMO

Referring to the natural succession to restore polluted land is one of the most vital assignments to solving the environmental problems. However, there is little understanding of the natural restoration of nutrient biogeochemical cycles in abandoned land with severe metal pollution. To clarify the nutrient cycling process and the influence of organisms on it, we investigated the magnitude of rhizosphere effects on soil nitrogen (N), phosphorus (P) and sulphur (S) cycles in natural restoration of an abandoned metal mine, as well as the roles of plants and microorganisms in the nutrient cycles. Our data revealed that the rhizosphere had higher levels of ammoniation than non-rhizosphere soil at both stages of restoration. In the early stage, the rhizosphere had greater levels of inorganic phosphorus and organophosphorus solubilisation, as well as sulphite oxidation, compared to non-rhizosphere soil. The bacterial composition influenced the N and S cycles, while the fungal composition had the greatest effect on the P cycles. Furthermore, rhizosphere nutrition cycles and microbial communities altered according plant strategy. Overall, the plants that colonize the early stages of natural recovery demonstrate enhanced restoration of nutrient efficiency. These results contribute to further knowledge of nutrient recovery in mining areas, as well as suggestions for selecting remedial microorganisms and plants in metal-polluted environments.

2.
Int J Mol Sci ; 25(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38892238

RESUMO

Flavonoids are secondary metabolites that play important roles in the resistance of plants to abiotic stress. Despite the widely reported adverse effects of lead (Pb) contamination on maize, the effects of Pb on the biosynthetic processes of flavonoids in maize roots are still unknown. In the present work, we employed a combination of multi-omics and conventional assay methods to investigate the effects of two concentrations of Pb (40 and 250 mg/kg) on flavonoid biosynthesis in maize roots and the associated molecular regulatory mechanisms. Analysis using conventional assays revealed that 40 and 250 mg/kg Pb exposure increased the lead content of maize root to 0.67 ± 0.18 mg/kg and 3.09 ± 0.02 mg/kg, respectively, but they did not result in significant changes in maize root length. The multi-omics results suggested that exposure to 40 mg/kg of Pb caused differential expression of 33 genes and 34 metabolites related to flavonoids in the maize root system, while 250 mg/kg of Pb caused differential expression of 34 genes and 31 metabolites. Not only did these differentially expressed genes and metabolites participate in transferase activity, anthocyanin-containing compound biosynthetic processes, metal ion binding, hydroxyl group binding, cinnamoyl transferase activity, hydroxycinnamoyl transferase activity, and flavanone 4-reductase activity but they were also significantly enriched in the flavonoid, isoflavonoid, flavone, and flavonol biosynthesis pathways. These results show that Pb is involved in the regulation of maize root growth by interfering with the biosynthesis of flavonoids in the maize root system. The results of this study will enable the elucidation of the mechanisms of the effects of lead on maize root systems.


Assuntos
Flavonoides , Regulação da Expressão Gênica de Plantas , Chumbo , Raízes de Plantas , Estresse Fisiológico , Transcriptoma , Zea mays , Zea mays/genética , Zea mays/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Flavonoides/biossíntese , Flavonoides/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Chumbo/toxicidade , Chumbo/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Fisiológico/genética , Metabolômica/métodos , Metaboloma/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
J Environ Manage ; 353: 120244, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38335599

RESUMO

On a global scale, the restoration of metal mine ecosystem functions is urgently required, and soil microorganisms play an important role in this process. Conventional studies frequently focused on the relationship between individual functions and their drivers; however, ecosystem functions are multidimensional, and considering any given function in isolation ignores the trade-offs and interconnectedness between functions, which complicates obtaining a comprehensive understanding of ecosystem functions. To elucidate the relationships between soil microorganisms and the ecosystem multifunctionality (EMF) of metal mines, this study investigated natural restoration of metal mines, evaluated the EMF, and used high-throughput sequencing to explore the bacterial and fungal communities as well as their influence on EMF. Bacterial community diversity and composition were more sensitive to mine restoration than fungal community. Bacterial diversity exhibited redundancy in improving N-P-K-S multifunctionality; however, rare bacterial taxa including Dependentiae, Spirochaetes, and WPS-2 were important for metal multifunctionality. Although no clear relationship between fungal diversity and EMF was observed, the abundance of Glomeromycota had a significant effect on the three EMF categories (N-P-K-S, carbon, and metal multifunctionality). Previous studies confirmed a pronounced positive association between microbial diversity and multifunctionality; however, the relationship between microbial diversity and multifunctionality differs among functions' categories. In contrast, the presence of critical microbial taxa exerted stronger effects on mine multifunctionality.


Assuntos
Ecossistema , Microbiota , Solo , Microbiologia do Solo , Bactérias/genética , Metais
4.
Ecotoxicol Environ Saf ; 250: 114498, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36608568

RESUMO

The understanding of bacterial resistance to hexavalent chromium [Cr(VI)] are crucial for the enhancement of Cr(VI)-polluted soil bioremediation. However, the mechanisms related to plant-associated bacteria remain largely unclear. In this study, we investigate the resistance mechanisms and remediation potential of Cr(VI) in a plant-associated strain, AN-B15. The results manifested that AN-B15 efficiently reduced Cr(VI) to soluble organo-Cr(III). Specifically, 84.3 % and 56.5 % of Cr(VI) was removed after 48 h in strain-inoculated solutions supplemented with 10 and 20 mg/L Cr(VI) concentrations, respectively. Transcriptome analyses revealed that multiple metabolic systems are responsible for Cr(VI) resistance at the transcriptional level. In response to Cr(VI) exposure, strain AN-B15 up-regulated the genes involved in central metabolism, providing the reducing power by which enzymes (ChrR and azoR) transformed Cr(VI) to Cr(III) in the cytoplasm. Genes involved in the alleviation of oxidative stress and DNA repair were significantly up-regulated to neutralize Cr(VI)-induced toxicity. Additionally, genes involved in organosulfur metabolism and certain ion transporters were up-regulated to counteract the starvation of sulfur, molybdate, iron, and manganese induced by Cr(VI) stress. Furthermore, a hydroponic culture experiment showed that toxicity and uptake of Cr(VI) by plants under Cr(VI) stress were reduced by strain AN-B15. Specifically, strain AN-B15 inoculation increased the fresh weights of the wheat root and shoot by 55.5 % and 18.8 %, respectively, under Cr(VI) stress (5 mg/L). The elucidation of bacterial resistance to Cr(VI) has an important implication for exploiting microorganism for the effective remediation of Cr(VI)-polluted soils.


Assuntos
Cromo , Pseudomonas , Pseudomonas/genética , Pseudomonas/metabolismo , Cromo/análise , Bactérias/metabolismo , Ferro/metabolismo , Biodegradação Ambiental
5.
Ecotoxicol Environ Saf ; 266: 115527, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37806135

RESUMO

Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Plântula/metabolismo , Ferro/metabolismo , Estresse Oxidativo , Bactérias/metabolismo , Poluentes do Solo/análise , Raízes de Plantas/metabolismo
6.
Int J Mol Sci ; 24(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37298252

RESUMO

Stomata are one of the important structures for plants to alleviate metal stress and improve plant resistance. Therefore, a study on the effects and mechanisms of heavy metal toxicity to stomata is indispensable in clarifying the adaptation mechanism of plants to heavy metals. With the rapid pace of industrialization and urbanization, heavy metal pollution has been an environmental issue of global concern. Stomata, a special physiological structure of plants, play an important role in maintaining plant physiological and ecological functions. Recent studies have shown that heavy metals can affect the structure and function of stomata, leading to changes in plant physiology and ecology. However, although the scientific community has accumulated some data on the effects of heavy metals on plant stomata, the systematic understanding of the effects of heavy metals on plant stomata remains limited. Therefore, in this review, we present the sources and migration pathways of heavy metals in plant stomata, analyze systematically the physiological and ecological responses of stomata on heavy metal exposure, and summarize the current mechanisms of heavy metal toxicity on stomata. Finally, the future research perspectives of the effects of heavy metals on plant stomata are identified. This paper can serve as a reference for the ecological assessment of heavy metals and the protection of plant resources.


Assuntos
Metais Pesados , Poluentes do Solo , Metais Pesados/metabolismo , Plantas/metabolismo , Poluição Ambiental , Fenômenos Fisiológicos Vegetais , Poluentes do Solo/metabolismo , Solo/química
7.
Bull Environ Contam Toxicol ; 104(3): 358-365, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31975014

RESUMO

Variations of phytoaccumulation and tolerance in different growth stages of plant are important factors for effective removal of pollutants in phytoremediation. The present work investigated arsenic (As) accumulation, As-tolerance and the physiological tolerance mechanisms of Typha angustifolia under different As-level during the seedling, fast-growing and breeding stages. The results showed that As mainly distributed in the underground part and total As accumulation increased with growth stages. Maximum growth rates under lower As occurred in seedling stage, whereas occurred in breeding stage under higher As. T. angustifolia exhibited the highest tolerance ability under 150 mg kg-1 As and tolerance index (TI) varied from seedling to breeding stages. During seedling stage, TI was affected by plant height (Hshoot) and net photosynthesis, which control biomass production. During fast-growing stage, Hshoot and root glutathione (GSH) co-regulated plant As-tolerance. During breeding stage, physiological metabolic processes, especially GSH-mediated processes, played a critical role in improving plant As-tolerance.


Assuntos
Aclimatação , Arsênio/análise , Typhaceae/crescimento & desenvolvimento , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Biomassa , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Typhaceae/metabolismo
8.
Environ Pollut ; 359: 124601, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39047889

RESUMO

An in-depth understanding of the micro-ecological mechanisms underlying the remediation of heavy metal-contaminated soils by biochar amendment is crucial for enhancing the efficacy of biochar-microbe combination. Nevertheless, this remediation mechanism remains elusive. Consequently, we performed a pot experiment to investigate the effects of biochar on soil fungal communities in a cadmium (Cd) and lead (Pb) contaminated soil. The results demonstrated that the amendment of biochar derived from rice straw significantly reshaped soil fungal communities, leading to the enrichment of members of the genus Aspergillus, which was found to correlate significantly with the remediation of heavy metal-contaminated soil. A representative of the targeted Aspergillus species (strain F8) was successfully isolated. The results of the pot experiments demonstrated that the inoculation with the isolate F8 can promote plant growth, immobilize soil Cd and Pb, and decrease tomato plant uptake of Cd and Pb. These results indicate that the enrichment of specific taxa induced by biochar amendment is associated with the remediation of heavy metal-contaminated soil. Therefore, this study provides new evidence to support the indirect mechanism of biochar in the remediation of heavy metal-contaminated soil by reshaping the soil microbiome.


Assuntos
Aspergillus , Biodegradação Ambiental , Cádmio , Carvão Vegetal , Chumbo , Microbiologia do Solo , Poluentes do Solo , Carvão Vegetal/química , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Chumbo/metabolismo , Aspergillus/metabolismo , Solo/química , Oryza/microbiologia , Recuperação e Remediação Ambiental/métodos
9.
Environ Sci Pollut Res Int ; 31(2): 1941-1953, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38044401

RESUMO

The combination of biochar and bacteria is a promising strategy for the remediation of Cd-polluted soils. However, the synergistic mechanisms of biochar and bacteria for Cd immobilization remain unclear. In this study, the experiments were conducted to evaluate the effects of the combination of biochar and Pseudomonas sp. AN-B15, on Cd immobilization, soil enzyme activity, and soil microbiome. The results showed that biochar could directly reduce the motility of Cd through adsorption and formation of CdCO3 precipitates, thereby protecting bacteria from Cd toxicity in the solution. In addition, bacterial growth further induces the formation of CdCO3 and CdS and enhances Cd adsorption by bacterial cells, resulting in a higher Cd removal rate. Thus, bacterial inoculation significantly enhances Cd removal in the presence of biochar in the solution. Moreover, soil incubation experiments showed that bacteria-loaded biochar significantly reduced soil exchangeable Cd in comparison with other treatments by impacting soil microbiome. In particular, bacteria-loaded biochar increased the relative abundance of Bacillus, Lysobacter, and Pontibacter, causing an increase in pH, urease, and arylsulfatase, thereby passivating soil exchangeable Cd and improving soil environmental quality in the natural alkaline Cd-contaminated soil. Overall, this study provides a systematic understanding of the synergistic mechanisms of biochar and bacteria for Cd immobilization in soil and new insights into the selection of functional strain for the efficient remediation of the contaminated environments by bacterial biochar composite.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Poluentes do Solo/análise , Carvão Vegetal , Solo , Bactérias
10.
Life Sci ; 354: 122952, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39127317

RESUMO

The bidirectional regulation between the gut microbiota and brain, known as gut-brain axis, has received significant attention. The myelin sheath, produced by oligodendrocytes or Schwann cells, is essential for efficient nervous signal transmission and the maintenance of brain function. Growing evidence shows that both oligodendrogenesis and myelination are modulated by gut microbiota and its metabolites, and when dysbiosis occurs, changes in the microbiota composition and/or associated metabolites may impact developmental myelination and the occurrence of neurodevelopmental disabilities. Although the link between the microbiota and demyelinating disease such as multiple sclerosis has been extensively studied, our knowledge about the role of the microbiota in other myelin-related disorders, such as neurodegenerative diseases, is limited. Mechanistically, the microbiota-oligodendrocyte axis is primarily mediated by factors such as inflammation, the vagus nerve, endocrine hormones, and microbiota metabolites as evidenced by metagenomics, metabolomics, vagotomy, and morphological and molecular approaches. Treatments targeting this axis include probiotics, prebiotics, microbial metabolites, herbal bioactive compounds, and specific dietary management. In addition to the commonly used approaches, viral vector-mediated tracing and gene manipulation, integrated multiomics and multicenter clinical trials will greatly promote the mechanistic and interventional studies and ultimately, the development of new preventive and therapeutic strategies against gut-oligodendrocyte axis-mediated brain impairments. Interestingly, recent findings showed that microbiota dysbiosis can be induced by hippocampal myelin damage and is reversible by myelin-targeted drugs, which provides new insights into understanding how hippocampus-based functional impairment (such as in neurodegenerative Alzheimer's disease) regulates the peripheral homeostasis of microbiota and associated systemic disorders.


Assuntos
Eixo Encéfalo-Intestino , Doenças Desmielinizantes , Microbioma Gastrointestinal , Homeostase , Oligodendroglia , Microbioma Gastrointestinal/fisiologia , Humanos , Animais , Oligodendroglia/metabolismo , Homeostase/fisiologia , Doenças Desmielinizantes/metabolismo , Doenças Desmielinizantes/microbiologia , Eixo Encéfalo-Intestino/fisiologia , Disbiose/microbiologia , Bainha de Mielina/metabolismo
11.
Sci Total Environ ; 920: 171018, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38378054

RESUMO

The mechanism through which soil microorganisms mediate carbon and nutrient cycling during mine wasteland restoration remained unknown. Using soil metagenome sequencing, we investigated the dynamic changes in soil microbial potential metabolic functions during the transition from biological soil crusts (BSC) to mixed broad-conifer forest (MBF) in a typical PbZn mine. The results showed soil microorganisms favored carbon sequestration through anaerobic and microaerobic pathways, predominantly using efficient, low-energy pathways during succession. Genes governing carbon degradation and aerobic respiration increased by 19.56 % and 24.79 %, respectively, reflecting change toward more efficient and intensive soil carbon utilization in late succession. Nitrogen-cycling genes mediated by soil microorganisms met their maximum influence during early succession (sparse grassland, SGL), leading to a respective increase of 75.29 % and 76.81 % in the net potential nitrification rate and total nitrogen content. Mantel and correlation analyses indicated that TOC, TN, Zn and Cd contents were the main factors affecting the soil carbon and phosphorus cycles. Soil AP content emerged as the primary influencer of genes associated with the nitrogen cycle. These results shed light on the dynamic shifts in microbial metabolic activities during succession, providing a genetic insight into biogeochemical cycling mechanisms and underscoring crucial factors influencing soil biogeochemical processes in mining regions.


Assuntos
Nitrogênio , Solo , Solo/química , Nitrogênio/análise , Carbono/análise , Fósforo , Florestas , Microbiologia do Solo
12.
Chemosphere ; 340: 139770, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37562505

RESUMO

Globally, reducing carbon emissions and mitigating soil heavy metal pollution pose pressing challenges. We evaluated the effects of lead (Pb) and cadmium (Cd) contamination in the field over 20 years. The five treatment groups featured Pb concentrations of 40 and 250 mg/kg, Cd concentrations of 10 and 60 mg/kg, and a combination of Pb and Cd (60 and 20 mg/kg, respectively); we also included a pollution-free control group. After 20 years, soil pH decreased notably in all treatments, particularly by 1.02 in Cd10-treated soil. In addition to the increase of SOC in Cd10 and unchanged in Pb40 treatment, the SOC was reduced by 9.62%-12.98% under the other treatments. The α diversities of bacteria and fungi were significantly changed by Cd10 pollution (both p < 0.05) and the microbial community structure changed significantly. However, there were no significant changes in bacterial and fungal communities under other treatments. Cd10 pollution reduced the numbers of Ascomycota and Basidiomycota fungi, and enhanced SOC accumulation. Compared to the control, long-term heavy Cd, Pb, and Pb-Cd composite pollution caused SOC loss by increasing Basidiomycota which promoting carbon degradation, and decreasing Proteobacteria which promoting carbon fixation via the Krebs cycle. Our findings demonstrate that heavy metal pollution mediates Carbon-cycling microorganisms and genes, impacting SOC storage.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/análise , Carbono/metabolismo , Solo/química , Chumbo/metabolismo , Metais Pesados/análise , Fungos , Poluentes do Solo/análise
13.
Sci Total Environ ; 904: 166871, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37683844

RESUMO

The drivers and mechanisms underlying succession and the spontaneous formation of plant communities in mining wasteland remain largely unknown. This study investigated the use of nature-based restoration to facilitate the recovery of viable plant communities in mining wasteland. It was found that scientific analyses of spontaneously formed plant communities in abandoned mining areas can provide insights for nature-based restoration. A chronosequence ("space for time") approach was used to establish sites representing three successional periods with six successional stages, and 90 quadrats were constructed to investigate changes in plant species and functional diversity during succession in abandoned PbZn mining areas. A total of 140 soil samples were collected to identify changes in soil properties, including plant nutrient and heavy metal concentrations. Then, this paper used structural equation models to analyze the mechanisms that drive succession. It was found that the functional diversity of plant communities fluctuated substantially during succession. Species had similar functional traits in early and mid-succession, but traits tended to diverge during late succession. Soil bulk density and soil organic matter gradually increased during succession. Total nitrogen (N), pH, and soil Zn concentrations first increased and then decreased during succession. Concentrations of Mn and Cd gradually decreased during succession. During early succession, soil organic matter was the key factor driving plant colonization and succession. During mid-succession, soil Zn functioned as an environmental filter factor limiting the rates of succession in mining wasteland communities. During late succession, soil bulk density and competition for nutrient resources contributed to more balanced differentiation among plant species. This thesis proposed that a nature-based strategy for the stabilization of abandoned mining lands could facilitate effective plant community restoration that promotes ecosystem services and functioning.


Assuntos
Ecossistema , Metais Pesados , China , Metais Pesados/análise , Plantas , Solo/química
14.
Sci Total Environ ; 806(Pt 2): 150626, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34597554

RESUMO

Mining is the most destructive human activity towards ecosystems through changing the terrain, substrate properties, and vegetation community structure. Vegetation succession, the theoretical basis of restoration, is influenced by site conditions and anthropogenic intervention. In order to provide general practical applications for mine restoration, it is critical to identify the optimal intervention that promotes succession, and the influence of climates. Here, we hypothesized that high-intervention contributes to positive characteristics and more successful succession, while increasing climatic severity presents negative characteristics and succession is hard to succeed. In this study, we collected 55 global studies (n = 804) on the vegetation succession of abandoned metal mines, and evaluated the ecological characteristics and successional trends under spontaneous succession and anthropogenic intervention conditions by conducting meta-analyses. Furthermore, we considered factors that may affect the vegetation succession after closing mines, including geological conditions, mining area (area of degraded land in mine field) and mining time (duration of mining operations). Species richness and evenness increased with the age of succession under low- and non- intervention conditions, while coverage increased under high-intervention, and species diversity decreased significantly with increasing mining time in cold areas. There were significant differences in succession trends under different climate types. The vegetation structure was more likely to develop towards the target vegetation in megathermal and mesothermal than in microthermal regions. We contend that a low level of intervention can help succession, while high-intervention will not. Vegetation succession can be achieved more easily with less climatic severity, and the reduction of large-scale mining processes (area and time) can increase vegetation evenness, especially for continental or microthermal regions.


Assuntos
Ecossistema , Solo , Humanos , Metais , Mineração
15.
Ecol Evol ; 12(5): e8882, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35509610

RESUMO

The mechanisms governing community assembly is fundamental to ecological restoration and clarification of the assembly processes associated with severe disturbances (characterized by no biological legacy and serious environmental problems) is essential. However, a systematic understanding of community assembly in the context of severe anthropogenic disturbance remains lacking. Here, we explored community assembly processes after metal mining, which is considered to be a highly destructive activity to provide insight into the assembly rules associated with severe anthropogenic disturbance. Using a chronosequence approach, we selected vegetation patches representing different successional stages and collected data on eight plant functional traits from each stage. The traits were classified as establishment and regenerative traits. Based on these traits, null models were constructed to identify the processes driving assembly at various successional stages. Comparison of our observations with the null models indicated that establishment and regenerative traits converged in the primary stage of succession. As succession progressed, establishment traits shifted to neutral assembly, whereas regeneration traits alternately converged and diverged. The observed establishment traits were equal to expected values, whereas regenerative traits diverged significantly after more than 20 years of succession. Furthermore, the available Cr content was linked strongly to species' ecological strategies. In the initial stages of vegetation succession in an abandoned metal mine, the plant community was mainly affected by the available metal content and dispersal limitation. It was probably further affected by strong interspecific interaction after the environmental conditions had improved, and stochastic processes became dominant during the stage with a successional age of more than 20 years.

16.
Transl Pediatr ; 10(4): 790-806, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34012829

RESUMO

BACKGROUND: The composition of intestinal flora in Chinese and Japanese has been reported in many studies but that in infants aged 0-6 years old has not been studied yet. METHODS: The distribution characteristics of the fecal flora of infants in Beijing (n=84) and Japan (n=53) were analyzed using 16S rRNA gene sequencing analysis. RESULTS: This study showed the higher relative abundance of Erysipelotrichaceae_ UCG-003 and Anaerostipes in male group that of Ruminiclostridium, Eubacterium, Senegalimassilia and Senegalimassilia in female group, especially Senegalimassilia, which was not detected in male group. Defecation trait groups indicated significantly higher relative abundance of Bifidobacterium in abnormal bowel trait group than that in the normal group (P<0.05). The feeding groups' analysis showed significantly higher relative abundance of Bifidobacterium and Enterococcus and lower abundance of Bacteroides and Lacetospirillaceae in the breast-feeding group than that in the formula feeding and mixed-feeding groups. The relative abundance of Parasutterella and Ruminococcaceae_UCG-003 in the halitosis group was significantly higher than that in the normal group. The comparison of cold and fever group and normal group indicated significantly higher relative abundance of Erysipelatoclostridium and lower relative abundance of Lachnospiraceae _UCG-001 in the fever and cold group than that in the normal group (P<0.05). The regional comparison of intestinal flora of Beijing and Japan showed significant increase in the relative abundance of Bacillus, Lactobacillus, Prevotella, megamonas and Veillonella in the intestinal flora of 0-6 years old infants in Beijing. CONCLUSIONS: These findings improve the understanding of intestinal bacterial and viral communities of infants from the two Asian countries.

17.
Artigo em Inglês | MEDLINE | ID: mdl-32013097

RESUMO

Much of the supervision incivility research has focused on the supervisor-subordinate dyad when examining the effects of supervision incivility on employee outcomes. Our study examines a trickle-down effect of supervision incivility across three hierarchical levels, i.e., from the department leader (middle manager), through group leader (supervisor), and to group members (employees), and how it affects group psychological safety. Drawing on a sample of 346 employees and 78 group leaders in 78 work groups, our research found a negative relationship between department leader incivility and group psychological safety, and that this negative relationship was mediated by group leader incivility and moderated by group leader attribution for performance-promotion or injury-initiation motives. We further discuss the theoretical and practical implications of these findings.


Assuntos
Processos Grupais , Incivilidade , Saúde Ocupacional , Local de Trabalho/psicologia , Humanos , Liderança , Motivação , Percepção Social
18.
Artigo em Inglês | MEDLINE | ID: mdl-33198286

RESUMO

Previous research on antecedents to constructive deviance remains scattered and inclusive. Our study conceptualizes constructive deviance from the perspective of ethical decision making and explores its antecedents, mechanism, and conditions. Drawing on moral licensing theory and social information processing theory, we propose that group citizenship behavior facilitates moral justification and constructive deviance when environmental dynamism is high and inhibits them when it is low; and moral justification fully mediates the relationship between the interaction of group citizenship behavior and environmental dynamism and constructive deviance. With two-wave panel data collected from 339 employees in 54 groups of five service companies in retailing, finance, and tourism randomly selected from three provinces in southern China, these hypotheses are all supported empirically. Our findings broaden the antecedents and occurrence mechanism of constructive deviance through an ethical decision-making lens. Our study contributes to the moral licensing literature by enriching the sources of moral licensing in the workplace and empirically demonstrating that moral justification may function as an underlying mechanism of moral licensing.


Assuntos
Tomada de Decisões , Princípios Morais , Local de Trabalho , China , Tomada de Decisões/ética , Feminino , Processos Grupais , Humanos , Masculino , Local de Trabalho/psicologia , Local de Trabalho/estatística & dados numéricos
19.
Artigo em Inglês | MEDLINE | ID: mdl-32784824

RESUMO

This research investigates the role of emotional exhaustion and supervisor incivility in explaining the relationship between work-related identity discrepancy and counterproductive work behavior. Based on resource conservation theory, our study hypothesizes a moderated mediation model that work-related identity discrepancy impacts counterproductive work behavior through emotional exhaustion, and supervisor incivility is deemed as the boundary condition in the indirect effect. Drawing on a sample of 863 employees, we found support for the moderated mediation model in which the positive relationship between work-related identity discrepancy and counterproductive work behavior was mediated by emotional exhaustion, such that the mediating relationship was strengthened for new leaders with a low level of supervisor incivility and weakened for those with high level of supervisor incivility. We further discuss the theoretical and practical implications of these findings.


Assuntos
Incivilidade , Local de Trabalho , Emoções , Feminino , Humanos , Relações Interpessoais , Masculino , Ocupações , Autoimagem
20.
Artigo em Inglês | MEDLINE | ID: mdl-32842458

RESUMO

Extant research on work-related identity discrepancy mostly has probed its effects on employees' attitudes and emotions but has paid little attention to its impact on employee behaviors. Drawing on self-discrepancy theory, we examined the influencing mechanism and conditions of work-related identity discrepancy on employee innovation behavior. With data collected from 563 employees who personally experienced leadership transition in the workplace, we found that work-related identity discrepancy predicts employee innovation behavior through workplace anxiety. We also discovered that employees' personality traits-promotion regulatory focus and prevention regulatory focus in particular-can intensify or buffer the negative relationship between work-related identity discrepancy and employee innovation behavior. We further discuss the conceptual and practical implications of these findings.


Assuntos
Ansiedade/psicologia , Criatividade , Relações Interpessoais , Estresse Ocupacional/psicologia , Autoeficácia , Local de Trabalho/psicologia , Adulto , Idoso , Transtornos de Ansiedade , Estudos Transversais , Feminino , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Ocupações , Cultura Organizacional , Inovação Organizacional , Apoio Social
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