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1.
Chemosphere ; 363: 143015, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39103103

RESUMEN

Due to the bioavailability and movement of antimony in trophic web, the overexploitation of antimony mine resulted in antimony contamination that harmed the ecology nearby, raising concerns for public health. Whereas, most researches focused on the removal of antimony in the aqueous instead of the immobilization of antimony in the soil. Herein, the immobilized performance of biochar (BC) loaded with nano zero-valent iron (nZVI-BC) on antimony in the soil near the smelting area was researched through pot experiments for the first time, and its stabilization mechanism on antimony was investigated by valent state variation of antimony. The results demonstrated that BC restricted the cation exchange capacity and catalase activity in the soil, while nZVI-BC had a favorable and negative impact on two variables, respectively. The nZVI-BC showed more stable immobilization capacity on antimony over time than BC, whose exchangeable speciation only marginally rose (2%-6%), although the exchangeable speciation of antimony fell both from 15% to 2% after adding the BC and nZVI-BC, The electron attraction force between nZVI-BC and antimony was also intensified owing to the oxidation-reduction process, which was considered as the stabilizing principle of nZVI-BC on antimony in soil. Furthermore, the decreased bioaccumulation factor for the perennial ryegrass (0.46-0.21) and Galinsoga parviflora Cav. (0.26-0.17) stated that the BC effectively mitigated the bioaccumulation risk of antimony.


Asunto(s)
Antimonio , Carbón Orgánico , Restauración y Remediación Ambiental , Hierro , Minería , Contaminantes del Suelo , Suelo , Antimonio/química , Carbón Orgánico/química , Contaminantes del Suelo/química , Contaminantes del Suelo/análisis , Hierro/química , Restauración y Remediación Ambiental/métodos , Suelo/química , Disponibilidad Biológica
2.
J Hazard Mater ; 470: 133740, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38569335

RESUMEN

The fate of fluoroquinolone antibiotics norfloxacin and ofloxacin were investigated in mesocosmic wetlands, along with their effects on nutrients removal, antibiotic resistance genes (ARGs) and epiphytic microbial communities on Hydrilla verticillate using bionic plants as control groups. Approximately 99% of norfloxacin and ofloxacin were removed from overlaying water, and H. verticillate inhibited fluoroquinolones accumulation in surface sediments compared to bionic plants. Partial least squares path modeling showed that antibiotics significantly inhibited the nutrient removal capacity (0.55) but had no direct effect on plant physiology. Ofloxacin impaired wetland performance more strongly than norfloxacin and more impacted the primary microbial phyla, whereas substrates played the most decisive role on microbial diversities. High antibiotics concentration shifted the most dominant phyla from Proteobacteria to Bacteroidetes and inhibited the Xenobiotics biodegradation function, contributing to the aggravation in wetland performance. Dechloromonas and Pseudomonas were regarded as the key microorganisms for antibiotics degradation. Co-occurrence network analysis excavated that microorganisms degrade antibiotics mainly through co-metabolism, and more complexity and facilitation/reciprocity between microbes attached to submerged plants compared to bionic plants. Furthermore, environmental factors influenced ARGs mainly by altering the community dynamics of differential bacteria. This study offers new insights into antibiotic removal and regulation of ARGs accumulation in wetlands with submerged macrophyte.


Asunto(s)
Antibacterianos , Biodegradación Ambiental , Microbiota , Norfloxacino , Contaminantes Químicos del Agua , Humedales , Antibacterianos/farmacología , Contaminantes Químicos del Agua/metabolismo , Norfloxacino/farmacología , Microbiota/efectos de los fármacos , Hydrocharitaceae/metabolismo , Hydrocharitaceae/genética , Farmacorresistencia Microbiana/genética , Ofloxacino , Bacterias/genética , Bacterias/metabolismo , Bacterias/efectos de los fármacos , Genes Bacterianos , Fluoroquinolonas/metabolismo
3.
Sci Total Environ ; 915: 170122, 2024 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-38232840

RESUMEN

Antibiotic pollution and the evolution of antibiotic resistance genes (ARGs) are increasingly viewed as major threats to both ecosystem security and human health, and have drawn attention. This study investigated the fate of antibiotics in aqueous and sedimentary substrates and the impact of ecosystem shifts between water and sedimentary phases on resistome profiles. The findings indicated notable variations in the concentration and distribution patterns of antibiotics across various environmental phases. Based on the partition coefficient (Kd), the total antibiotic concentration was significantly greater in the surface water (1405.45 ng/L; 49.5 %) compared to the suspended particulate matter (Kd = 0.64; 892.59 ng/g; 31.4 %) and sediment (Kd = 0.4; 542.64 ng/g; 19.1 %). However, the relative abundance of ARGs in surface water and sediment was disproportionate to the abundance of antibiotics concentration, and sediments were the predominant ARGs reservoirs. Phylogenetic divergence of the microbial communities between the surface water and the sedimentary ecosystems potentially played important roles in driving the ARGs profiles between the two distinctive ecosystems. ARGs of Clinical importance; including blaGES, MCR-7.1, ermB, tet(34), tet36, tetG-01, and sul2 were significantly increased in the surface water, while blaCTX-M-01, blaTEM, blaOXA10-01, blaVIM, tet(W/N/W), tetM02, and ermX were amplified in the sediments. cfxA was an endemic ARG in surface-water ecosystems while the endemic ARGs of the sedimentary ecosystems included aacC4, aadA9-02, blaCTX-M-04, blaIMP-01, blaIMP-02, bla-L1, penA, erm(36), ermC, ermT-01, msrA-01, pikR2, vgb-01, mexA, oprD, ttgB, and aac. These findings offer a valuable information for the identification of ARGs-specific high-risk reservoirs.


Asunto(s)
Genes Bacterianos , Agua , Humanos , Ecosistema , Filogenia , Ríos , Antibacterianos/análisis
4.
Sci Total Environ ; 904: 166710, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37652383

RESUMEN

Wetlands are the largest natural methane source, but how submerged macrophytes affect methane emission remains controversial. In this study, the impacts of submerged macrophytes on methane fluxes, water purification, and epiphytic microbial community dynamics were investigated in simulated wetlands (with and without Hydrilla verticillata) treated with norfloxacin (NOR) for 24 days. Mean methane fluxes were significantly lower in treatments with Hydrilla verticillata (56.84-90.94 mg/m2/h) than bulks (65.96-113.21 mg/m2/h) (p < 0.05) during the experiment regardless of NOR. The relative conductivity (REC) values, H2O2, and malondialdehyde (MDA) contents increased in plant leaves, while water nutrients removal rates decreased with increasing NOR concentration at the same sampling time. The partial least squares path model analysis revealed that plant physiological indices and water nutrients positively affected methane fluxes (0.72 and 0.49, p < 0.001). According to illumina sequencing results of 16S rRNA and pmoA genes, α-proteobacteria (type II) and γ-proteobacteria (type I) were the dominant methanotroph classes in all epiphytic biofilms. The ratio of type I/type II methanotrophs and pmoA gene abundance in epiphytic biofilm was considerably lower in treatment with 16 mg/L NOR than without it (p < 0.05). pmoA gene abundance was negatively correlated with methane fluxes (p < 0.05). Additionally, the assembly of epiphytic bacterial community was mainly governed by deterministic processes, while stochastic dispersal limitation was the primary assembly process in the epiphytic methanotrophic community under NOR stress. The deterministic process gained more importance with time both in bacterial and methanotrophic community assembly. Network analysis revealed that relationships among bacteria in epiphytic biofilms weakened with time but associations among methanotrophic members were enhanced under NOR stress over time. It could be concluded that submerged macrophytes-epiphytic biofilms symbiotic system exhibited potential prospects to reduce methane emissions from wetlands under reasonable management.


Asunto(s)
Antibacterianos , Hydrocharitaceae , Antibacterianos/farmacología , Humedales , Metano , ARN Ribosómico 16S , Peróxido de Hidrógeno , Bacterias , Hydrocharitaceae/microbiología , Biopelículas , Norfloxacino , Agua
5.
Chin Med Sci J ; 38(2): 147-158, 2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37280723

RESUMEN

Objective To systematically analyze the current status of outcomes reporting in clinical trials on treating stasis acute mastitis with Traditional Chinese Medicine breast massage.Methods We searched CNKI, Wanfang, VIP, SinoMed, PubMed, Web of Science, Embase, Cochrane library, JBI, CINAHL, PsycINFO, Clinical Trials Registry Platform portal, Clinical Trials Registry, Australian New Zealand Clinical Trials Registry, Center Watch Registry from inception to May 15, 2022 to find randomized controlled trials, non-randomized controlled trials, case series and cohort studies which reported the outcomes of stasis acute mastitis managed with Traditional Chinese Medicine breast massage, with search terms of mastitis, acute mastitis, lactation mastitis, puerperal mastitis, breast problem, breast engorgement, milk stasis, blocked ducked, breast pain, breast massage, and acupoint massage. Outcomes and the measurement schemes (measurement methods, timing of assessing outcome, frequency of assessing outcome, measurers) were extracted from the included studies. We used the Management of Otitis Media with Effusion in Children with Cleft Palate (MOMENT) to assess the quality of each study, then categorized outcomes derived from the included studies into different domains according to the Outcome Measures in Rheumatology Arthritis Clinic Trials (OMERACT) Filter 2.1 framework.Results We identified 85 clinical trials, in which 54 different outcomes were reported. A total of 81.2% (69/85) of studies were assessed as medium quality with a mean score of 2.6, and 18.8% (16/85) as low quality with a mean score of 0.9. These outcomes were organized in three core areas. Lump size (89.4%, 76/85) was the most frequently reported outcome, followed by breast pain (69.4%, 59/85) and milk excretion (68.2%, 58/85). Five methods were used to assess lump size and four methods to assess breast pain.Conclusions The outcomes reported in clinical trials regarding stasis acute mastitis treated by Traditional Chinese Medicine breast massage are heterogeneous. Developing a core outcome set to achieve consistent standards for reporting outcomes and modalities for validation of the outcomes is clearly warranted.


Asunto(s)
Mastitis , Mastodinia , Niño , Femenino , Humanos , Australia , Masaje , Mastitis/terapia , Medicina Tradicional China
6.
Environ Sci Pollut Res Int ; 30(25): 66431-66444, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37101213

RESUMEN

Antibiotic residues in aquatic environments pose a potential hazard, and microbes, which play important roles in aquatic ecosystems, are vulnerable to the impacts of antibiotics. This study aimed to analyze the research progress, trends, and hot topics of the impact of antibiotics on microbial community and biodegradation mechanism using bibliometric analysis. An in-depth analysis of the publication characteristics of 6143 articles published between 1990 and 2021 revealed that the number of articles published increased exponentially. The research sites have been mainly concentrated in the Yamuna River, Pearl River, Lake Taihu, Lake Michigan, Danjiangkou Reservoir, etc., illustrating that research around the world is not even. Antibiotics could change the diversity, structure, and ecological functions of bacterial communities, stimulate a widespread abundance of antibiotic-resistant bacteria and antibiotic-resistant genes, and increase the diversity of eukaryotes, thus triggering the shift of food web structure to predatory and pathogenic. Latent Dirichlet allocation theme model analysis showed three clusters, and the research hotspots mainly included the effect of antibiotics on the denitrification process, microplastics combined with antibiotics, and methods for removing antibiotics. Furthermore, the mechanisms of microbe-mediated antibiotic degradation were unraveled, and importantly, we provided bottlenecks and future research perspectives on antibiotics and microbial diversity research.


Asunto(s)
Microbiota , Plásticos , Antibacterianos/farmacología , Bacterias/genética , Bibliometría
8.
J Oncol ; 2023: 2339732, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36644234

RESUMEN

Background: Ubiquilin 2 (UBQLN2) is an adaptor of ubiquitinated proteins and the proteasome. The potential role of UBQLN2 in carcinogenesis has been demonstrated. However, its role in modulating the radiosensitivity of cancer is not clear. Here, we explored the radiosensitizing effect of silencing UBQLN2 on esophageal squamous cell carcinoma (ESCC) and its mechanisms. Methods: We analyzed the prognostic role of UBQLN2 in the ESCC patient cohort from the Cancer Genomic Atlas (TCGA) database and our hospital. We also conducted a series of experiments in vivo and in vitro to investigate the effect of silencing UBQLN2 on ESCC radiosensitivity and its mechanisms. Results: UBQLN2 is highly expressed in ESCC tissues and positively correlated with poor overall survival (OS). The knockdown of UBQLN2 dramatically increased the radiosensitivity of ESCC cells. Mechanically, UBQLN2 suppression substantially upregulated p38 mitogen-activated protein kinases (MAPK). The p38 MAPK inhibitor SB203580 could reverse the radiation-enhancing effect induced by UBQLN2 knockdown. The direct interaction between UBQLN2 and p38 MAPK was confirmed by co-immunoprecipitation (CO-IP) assay. Furthermore, silencing UBQLN2 also inhibited the expression of phosphorylated DNA-dependent protein kinase catalytic subunit (p-DNA-PKcs) after irradiation. Finally, the xenografted tumor experiment confirmed the radiosensitizing effect of silencing UBQLN2 on ESCC in vivo. Conclusion: Our results suggest that silencing UBQLN2 enhances the radiosensitivity of ESCC by activating p38 MAPK, and UBQLN2 may be a potential target to enhance the radiosensitivity of ESCC.

9.
Bioresour Technol ; 332: 125134, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33845319

RESUMEN

The impacts of water flow and low temperature on nutrient removal and underlying ecological mechanism of epiphytic microbial community in constructed wetlands remain to be fully illustrated. In this study, low temperature inhibited the decrease of TN, NH4+-N, TP, and COD concentrations in water, but water flow decreased NH4+-N and COD concentrations strikingly. The relative conductivity, soluble sugar, and protein of M. spicatum increased, while the total chlorophyll contents decreased significantly under the stress of water flow and low temperature. Temperature affected the alpha-diversity and composition of the microbial community, while water flow caused differences in community distribution. Deterministic processes dominated in microbial community assembly with increasing environmental stress. Co-occurrence network analysis demonstrated that Chlorophyta, Verrucomicrobia, Proteobacteria, Bacteroidetes, and Firmicutes phyla were the dominant hubs in September, however, low temperatures caused a shift to Metazoan dominated network, demonstrating diminished nutrient removal capacity.


Asunto(s)
Microbiota , Humedales , Animales , Nitrógeno , Nutrientes , Temperatura , Eliminación de Residuos Líquidos , Agua
10.
Bioresour Technol ; 321: 124469, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33296776

RESUMEN

The impacts of WWTPs effluents on nutrients removal and epiphytic microbial community in constructed wetlands dominated by submersed macrophytes remain to be fully illustrated. In this study, compared to M. Spicatum, artificial submersed macrophytes (control) generally had higher NH4+-N (78.35% vs 80.52%) and TN (73.35% vs 90.25%) removal rates and similar COD (70.64% vs 70.80%) and TP (59.86% vs 60.82%) removal rates in wetlands receiving simulated effluents of WWTPs (GB18918-2002). Microbial population richness was higher in epiphytic biofilms on M. Spicatum than artificial ones, and substrates played the most decisive role in determining the microbial diversities. Network analysis revealed that there were more complex interactions among environmental parameters, bacteria and eukaryotes in M. Spicatum systems than in artificial ones. Nutrients in effluents could cause damage to M. Spicatum. The results highlight that artificial plants have better performance on effluents deep treatments than submerged plants.


Asunto(s)
Microbiota , Humedales , Bacterias , Biopelículas , Nitrógeno , Nutrientes
11.
Bioresour Technol ; 318: 124058, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32905946

RESUMEN

The mechanisms behind water flow on contaminant removal by a submerged macrophyte-biofilm complex in surface flow wetlands remain to be fully elucidated. In this study, water flow (2.02 ~ 2.12 or 4.06 ~ 4.5 L s-1; hydraulic retention time, 7d) significantly enhanced NH4+-N and COD but inhibited TN and TP removal compared to the static ones. No more than 30% of TN and TP were assimilated by V. natans-biofilm complex in wetland system. Water flow remarkably affected alpha-diversity of microbial community in epiphytic biofilm. As revealed by beta-diversity analysis, turnover played greater contribution to the total dissimilarity than nestedness. Network analyses revealed that the microbial interactions including predation, symbiosis and competition in epiphytic biofilms were much more intensive in the Sept.- Oct. than the Nov.-Dec group. Redundancy and Mantel correlation analyses revealed that temperature played a key role in determining microbial community structure, especially for bacteria.


Asunto(s)
Hydrocharitaceae , Microbiota , Nitrógeno , Nutrientes , Temperatura , Humedales
12.
Environ Pollut ; 266(Pt 2): 115203, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32711247

RESUMEN

The mechanisms behind nitrogen removal by the submersed macrophyte-biofilm complex in wetlands remain to be fully elucidated. This study investigated the role of Myriophyllum spicatum and the biofilm on their leaves in nitrogen removal in mesocosm experiments. 15N tracking showed that 61.9% and 30% of the 15N, respectively, was removed from the system and assimilated by the macrophyte-biofilm complex after loading with 5.4 mg L-115N labelled NH4+ for 17 days. Nitrogen budget results showed that about 0.2%, 0.2% and 3.6% of the nitrogen were emitted as water-, HCl- and NaOH-soluble nitrogen-gas species, respectively. Bacteria (76.7-91.8%) were the predominant domain in all samples, followed by eukaryotes (8.0-23.0%), archaea and viruses. Network analyses showed that there were positive- and negative-correlative relationships among nitrogen-cycling genes and nitrifiers and denitrifiers. Our data highlight the important role of biofilm on submersed macrophytes for nitrogen removal.


Asunto(s)
Nitrógeno/análisis , Humedales , Biopelículas , Desnitrificación , Metagenómica , Nitrificación , Aguas Residuales
13.
J Environ Manage ; 269: 110814, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32561016

RESUMEN

Among nitrogen species, nitrate is more stable than ammonium and nitrite, and it is an important nitrogenous pollutant in surface water. However, little is known about the characterization of epiphytic microbial communities on submersed macrophytes under nitrate loading. In this study, we investigated the co-occurring pattern and response of bacteria and microeukaryotes in epiphytic biofilms under nitrate loading. Nitrate loading significantly affected bacterial and eukaryotic communities, and turnover played greater contribution to the total dissimilarity than nestedness by partitioning beta-diversity analysis. Cyanobacteria, α-proteobacteria, ß-proteobacteria, Actinobacteria, Planctomycetes, Bacteroidetes, and γ-proteobacteria were dominant bacterial phyla/classes. Metazoan (phylum Arthropoda, Rotifera, Gastrotricha, Annelida, and Nematoda) and algae (phylum Bacillariophyta, Chlorophyta, and Streptophyta) were dominated in eukaryotic communities. The abundances of denitrifying bacteria (Rhodobacter, Acinetobacter, Bacillus, Flavobacterium, and Pseudomonas) and genes (nirS, cnorB, and nosZ) increased with nitrate loading. The network analysis showed there were complex interactions among photosynthetic microbes, metazoan, and bacteria (including denitrifiers) that they were potentially interrelated via photosynthesis, predation or feeding. This study provides new perspectives into understanding the factors affecting nitrate removal mechanisms in wetlands with submersed macrophytes.


Asunto(s)
Biodiversidad , Microbiota , Animales , Biopelículas , Desnitrificación , Nitratos , Humedales
14.
Sci Total Environ ; 715: 136950, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32007899

RESUMEN

Microbes in epiphytic biofilms and surface sediments play crucial roles in the biogeochemical cycles in wetlands. However, little is known about the compositions of microbial community in wetlands dominated with submersed macrophytes. In this study, bacterial and eukaryotic community in epiphytic biofilms and surface sediments were investigated in wetlands with artificial plants and Myriophyllum verticillatum from September (~27 °C) to January (~9 °C). A total of 30 (including 13 bacterial and 17 eukaryotic) and 34 (including 14 bacterial and 20 eukaryotic) phyla were detected in epiphytic biofilms and sediments, respectively. Microbial community in epiphytic biofilms shifted with decreasing temperature, and biofilms on M. verticillatum were generally similar to those on artificial plants. Though the OTUs and Shannon values were significantly higher in sediments than epiphytic biofilms (p < 0.05), numbers of strongly correlated edges detected in biofilms (64 nodes with 182 edges) were at least three times of those in sediments (40 nodes with 57 edges) as revealed by co-occurrence networks analysis (|r| > 0.7, p < 0.05). These data suggest that there were complex interactions among microbes in epiphytic biofilms than sediments. Positive relationships among microbes revealed the predation, symbiosis, parasitism relationships and the collective degradation of organic matter, while negative ones may be ascribed to their different lifestyles. These results highlight that artificial plants play a similar role as submersed macrophytes as microbial carriers and can be potentially used an alternative substitutes to submersed macrophytes in wetlands.


Asunto(s)
Microbiota , Bacterias , Biopelículas , Eucariontes , Humedales
15.
Chemosphere ; 236: 124253, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31323556

RESUMEN

Epiphytic bacteria on submerged macrophytes play important roles in the nutrient cycle in freshwater ecosystems. However, little is known about the composition and role of epiphytic bacteria during the decomposition of submerged macrophytes. In this study, the alterations in epiphytic bacterial composition, abundances of nitrogen cycle-related genes and nutrient release were investigated in a 56-day decomposition process of Potamogeton malaianus. The total reduced biomass was positively related to the contents of carbon, nitrogen and phosphorus released from plant residues. Nutrient released from plant litter showed a positively effect on the concentrations of carbon, nitrogen and phosphorus in the overlying water (p < 0.01). The carbon, phosphorus and nitrogen decreased with decomposition process in both plant debris and overlying water. Humic acid-like substances were the main component of dissolved organic matter in the conditioning stage, whereas fulvic acid-like substances dominated in the fragmentation stage. Results from network analysis and canonical correspondence analysis showed dominant bacterial clades changed with decomposition process. Bacteroidetes was the most abundant phylum in the leaching stage and Spirochaetes, Chlorobi, and Bacteroidetes dominated in the conditioning stage, while Chlorobi dominated in the fragmentation stage. The highest abundance of cnorB and nosZ were detected in the leaching and fragmentation stage, respectively. Bacterial denitrification contributed to nitrogen removal and might be promoted by high ORP and DOC concentration. Our results indicate that epiphytic bacterial community shift drived the metabolism of nutrients C, N, and S during the decomposition of P. malaianus.


Asunto(s)
Bacterias/química , Nutrientes/química , Potamogetonaceae/química
16.
Sci Total Environ ; 659: 691-698, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31096399

RESUMEN

The knowledge about the impacts of ammonium loading on microbial food webs in biofilms attached to submersed macrophytes is limited. In the present study, Illumina sequencing method was employed to investigate bacterial and eukaryotic communities in biofilms attached to leaves of Vallisneria natans (V. natans) exposed to 1-16 mg L-1 NH4+-N for 10 days, and 8 mg L-1 NH4+-N for 21 days. Ammonium loading stimulated biofilms growth, enhanced the relative abundance of nitrifying genus Nitrospira and several denitrifying genera. Eukaryotic kingdom Metazoa, Viridiplantae, Chromista, Fungi and super group SARNU (Stramenopiles, Alveolata, Rhizaria, Nucleariidae and Fonticula group and unknown eukaryotes) were obtained. Relative abundance of Metazoa decreased with the increased ammonium concentration and exposure time. Redundancy analysis revealed that ammonium, dissolved oxygen (DO) and pH had a key role in determining microbial community structure. Network analyses revealed that there were complex interactions including feeding, parasitism and predatism among organism in biofilms, and the microbial food webs were disturbed by inhibiting metazoan growth but stimulating bacteria and algae growth. These results suggest that ammonium-disturbed microbial food webs in biofilms may contribute to the growth of biofilms and algae, and thus contribute to the decline of submersed macrophyte and provide "algal seeds" for the algae burst in water column. These data will be helpful in understanding the macrophytic region transform into algal region in water column polluted by ammonium.


Asunto(s)
Compuestos de Amonio/metabolismo , Fenómenos Fisiológicos Bacterianos , Biopelículas , Cadena Alimentaria , Hydrocharitaceae/microbiología , Microbiota/fisiología , Desnitrificación , Eucariontes/fisiología , Nitrificación , Humedales
17.
Physiol Mol Biol Plants ; 24(4): 605-616, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30042616

RESUMEN

Low temperature causes a negative impact on plant growth and development, but plants evolve a series of mechanisms to respond to chilling stress, and one of them is CBF [C-repeat (CRT)/dehydration-responsive element (DRE) binding factor] gene family which has been well studied in different crops. In this paper, a new CBF1 gene, named as SpCBF1, was isolated from frost-tolerant Solanum pinnatisectum by PCR and analyzed for its function in cold-tolerance by over-expression technique. The ORF of SpCBF1 was 666 bp long and encoded a protein of 221 amino acids with a predicted molecular mass 24.5821 kDa and theoretically isoelectric point 5.0. SpCBF1 protein contained a highly conserved specific AP2/ERF domain. SpCBF1 was expressed in all tested tissues with the highest level in tuber and the lowest in root, and induced by chilling stress (0 °C). Under natural low temperature condition (1-10 °C), plants over-expressing SpCBF1 (OE) exhibited slighter necrotic lesion and lower necrotic injury, compared with untransformed Solanum tuberosum cv. Désirée (WT) and antisense-StCBF1 control lines. Over-expression of CBF1 increased the level of COR (cold-regulated) gene transcripts in OE lines, and the physiological indexes related to cold tolerance like the contents of SOD, soluble protein, MDA, proline and soluble sugar were higher in OE lines than in WT except RWC which was lower. All these results indicated that SpCBF1 gene plays a promoting role in potato responding to cold stress.

18.
J Integr Plant Biol ; 57(12): 1078-88, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25735453

RESUMEN

Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present sRNA sequencing data revealed that miR482 was in response to V. dahliae infection, but the function in potato is elusive. Here, we characterized potato miR482 family and its putative role resistance to Verticillium wilt. Members of the potato miR482 superfamily are variable in sequence, but all variants target a class of disease-resistance proteins with nucleotide binding site (NBS) and leucine-rich repeat (LRR) motifs. When potato plantlets were infected with V. dahliae, the expression level of miR482e was downregulated, and that of several NBS-LRR targets of miR482e were upregulated. Transgenic potato plantlets overexpressing miR482e showed hypersensitivity to V. dahliae infection. Using sRNA and degradome datasets, we validated that miR482e targets mRNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting (ta)-siRNAs, most of which target mRNAs of defense-related proteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived ta-siRNA-mediated silencing on NBS-LRR-disease-resistance proteins. It is speculated that a miR482-mediated silencing cascade mechanism is involved in regulating potato resistance against V. dahliae infection and could be a counter defense action of plant in response to pathogen infection.


Asunto(s)
Resistencia a la Enfermedad/genética , MicroARNs/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Solanum tuberosum/genética , Solanum tuberosum/microbiología , Verticillium/fisiología , Secuencia de Bases , Sitios de Unión , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Silenciador del Gen , Genes de Plantas , Sitios Genéticos , Proteínas Repetidas Ricas en Leucina , MicroARNs/metabolismo , Datos de Secuencia Molecular , Plantas Modificadas Genéticamente , Proteínas/genética , Proteínas/metabolismo , ARN Interferente Pequeño/biosíntesis , Reproducibilidad de los Resultados
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