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1.
Sci Rep ; 9(1): 11660, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31406202

RESUMO

Both earthworms and plants may affect the soil nematode community. However, the effects of earthworms and plant species interactions on soil nematode community are poorly understood. We explored how an epigeic earthworm Eisenia fetida affects the soil nematode community in systems with three representative plants (wheat, cotton and cabbage) which were grown in pots with or without added earthworms under greenhouse conditions. Earthworm presence decreased the abundance of total nematode and all four nematode trophic groups, except for the fungivore and predator/omnivore nematodes in wheat systems, but increased the genus richness of nematode in all treatments. Due to plant identity and different root exudates, plants had significant effects on soil nematode abundance. Compared with the no plant and without earthworm treatment, wheat and cabbage had the higher stimulation of the abundance of total nematode, bacterivores and fungivores, and cotton had the higher stimulation of the abundance of fungivores and predators-omnivores; whereas earthworm presence mostly weakened the stimulation effects of plant species on soil nematode abundance which indicated earthworms had the enhanced effects in the presence of plants. The interaction affected soil nematode abundance (total nematodes, bacterivore, fungivore and omnivore-predators) and community diversity indices (diversity index H', evenness index J', community maturity index ∑MI, Simpson dominance index λ and nematode channel ratio NCR). Principal component analysis showed that plant species affected soil nematode community composition. Redundancy analysis indicated plant species and biomass accounted for 41.60% and 34.13% of the variation in soil nematode community structure, respectively; while earthworms explained only 6.13%. Overall, current study suggest that earthworm could inhibit nematode abundance; whereas, plants have exerted greater influences on nematode community structure than earthworm presence due to their species-specific effects on different trophic groups of nematodes.

2.
Biomed Pharmacother ; 99: 462-468, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29665647

RESUMO

Preeclampsia (PE), a common obstetrical disorder, is one of the leading causes of pregnancy associated death. PE is closely linked with impaired migration and invasion ability of trophoblastic cells. miR-362-3p recently received our particular attention due not only to its aberrant expression in the placentas of patients with PE, but also to its important roles in regulating migration and invasion of various cells. This study was thus conducted to investigate the roles of miR-362-3p in PE and the related mechanism. The expression of miR-362-3p and Pax3 was examined in placentas of patients with PE and in normal placentas. HTR8/SVneo cells were cultured under hypoxia and transfected with miR-362-3p mimics, miR-362-3p inhibitors or Pax3 over-expression vectors. Results showed up-regulation of miR-362-3p but down-regulation of Pax3 in placentas of preeclamptic pregnancies. Luciferase report assay confirmed that Pax3 is a direct target of miR-362-3p. Although Pax3 was predicted to be targeted by miR-30a-3p and miR-181a-5p as well, their expression either had no difference between placentas of PE patients and normal placentas or showed less increment in placentas of PE patients than miR-362-3p. Exposure to hypoxia inhibited cell viability, migration and invasion of HTR8/SVneo cells. Increasing miR-362-3p by the mimics conferred improved effects on the inhibition. However, deletion of miR-362-3p or overexpression of Pax3 abolished the inhibiton. These results suggest that miR-362-3p/Pax3 axis regulates cell viability, migration and invasion of HTR8/SVneo cells under hypoxia. The present study adds to the further understanding of the pathogenesis of PE.


Assuntos
Movimento Celular/genética , MicroRNAs/metabolismo , Fator de Transcrição PAX3/metabolismo , Trofoblastos/metabolismo , Trofoblastos/patologia , Adulto , Sequência de Bases , Estudos de Casos e Controles , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/genética , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , MicroRNAs/genética , Oxigênio/farmacologia , Fator de Transcrição PAX3/genética , Placenta/efeitos dos fármacos , Placenta/metabolismo , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/patologia , Gravidez , Trofoblastos/efeitos dos fármacos
3.
Free Radic Biol Med ; 120: 255-265, 2018 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-29580984

RESUMO

Genetically encoded fluorescent sensors are widely used to visualize secondary messengers, metabolites and dynamic events in living cells. However, almost all of these sensors are based on Aequorea GFPs or GFP-like proteins, which do not correctly maturate and fluoresce under hypoxia or anoxic conditions, greatly limiting their application in biomedical research. Herein, we provide a novel strategy for design of sensors and report a series of thiol redox-sensitive sensor based on a recently discovered oxygen-independent fluorescent protein UnaG from Japanese eel. These redox sensors have large dynamic range, rapid responsiveness, a flexible "switch", and pH-independence, are particularly compatible with hypoxia conditions, and therefore represent a substantial improvement for live-cell redox measurement. We further demonstrated the versatility of these redox sensors, by simultaneously monitoring redox changes and hypoxia state in living cells, thereby proving its capability as a powerful and flexible tool for indexing multidimensional metabolism data in the context of physiological stressors and pathological states. These redox sensors are not only the first case of UnaG-based functional sensors, but also the first case of functional sensors based on non GFP-like proteins. Based on this strategy, more oxygen-independent biosensors could be developed, hence, provide new opportunities for bioimaging.

4.
Sci Rep ; 7: 43479, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28252043

RESUMO

High-resolution spatiotemporal imaging of histidine in single living mammalian cells faces technical challenges. Here, we developed a series of ratiometric, highly responsive, and single fluorescent protein-based histidine sensors of wide dynamic range. We used these sensors to quantify subcellular free-histidine concentrations in glucose-deprived cells and glucose-fed cells. Results showed that cytosolic free-histidine concentration was higher and more sensitive to the environment than free histidine in the mitochondria. Moreover, histidine was readily transported across the plasma membrane and mitochondrial inner membrane, which had almost similar transport rates and transport constants, and histidine transport was not influenced by cellular metabolic state. These sensors are potential tools for tracking histidine dynamics inside subcellular organelles, and they will open an avenue to explore complex histidine signaling.


Assuntos
Proteínas de Bactérias/química , Técnicas Biossensoriais , Membrana Celular/metabolismo , Histidina/análise , Proteínas Luminescentes/química , Membranas Mitocondriais/metabolismo , Proteínas Periplásmicas de Ligação/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Transporte Biológico , Membrana Celular/efeitos dos fármacos , Rastreamento de Células , Clonagem Molecular , Citosol/efeitos dos fármacos , Citosol/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Transferência Ressonante de Energia de Fluorescência , Expressão Gênica , Glucose/metabolismo , Glucose/farmacologia , Células HeLa , Histidina/metabolismo , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Proteínas Periplásmicas de Ligação/genética , Proteínas Periplásmicas de Ligação/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais
5.
PLoS One ; 11(11): e0165979, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27855163

RESUMO

The frequent outbreaks of rice foot rot disease caused by Dickeya zeae have become a significant concern in rice planting regions and countries, but the regulatory mechanisms that govern the virulence of this important pathogen remain vague. Given that the second messenger cyclic di-GMP (c-di-GMP) is associated with modulation of various virulence-related traits in various microorganisms, here we set to investigate the role of the genes encoding c-di-GMP metabolism in the regulation of the bacterial physiology and virulence by construction all in-frame deletion mutants targeting the annotated c-di-GMP turnover genes in D. zeae strain EC1. Phenotype analyses identified individual mutants showing altered production of exoenzymes and phytotoxins, biofilm formation and bacterial motilities. The results provide useful clues and a valuable toolkit for further characterization and dissection of the regulatory complex that modulates the pathogenesis and persistence of this important bacterial pathogen.


Assuntos
GMP Cíclico/análogos & derivados , Enterobacteriaceae/genética , Enterobacteriaceae/metabolismo , Oryza/microbiologia , Característica Quantitativa Herdável , Fatores de Virulência/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biofilmes , GMP Cíclico/metabolismo , Enterobacteriaceae/patogenicidade , Flagelos/genética , Flagelos/metabolismo , Estudos de Associação Genética , Macrolídeos/metabolismo , Mutação , Doenças das Plantas/microbiologia , Poliaminas/metabolismo , Domínios e Motivos de Interação entre Proteínas , Virulência
6.
BMC Genomics ; 16: 571, 2015 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-26239726

RESUMO

BACKGROUND: Dickeya zeae is a bacterial species that infects monocotyledons and dicotyledons. Two antibiotic-like phytotoxins named zeamine and zeamine II were reported to play an important role in rice seed germination, and two genes associated with zeamines production, i.e., zmsA and zmsK, have been thoroughly characterized. However, other virulence factors and its molecular mechanisms of host specificity and pathogenesis are hardly known. RESULTS: The complete genome of D. zeae strain EC1 isolated from diseased rice plants was sequenced, annotated, and compared with the genomes of other Dickeya spp.. The pathogen contains a chromosome of 4,532,364 bp with 4,154 predicted protein-coding genes. Comparative genomics analysis indicates that D. zeae EC1 is most co-linear with D. chrysanthemi Ech1591, most conserved with D. zeae Ech586 and least similar to D. paradisiaca Ech703. Substantial genomic rearrangement was revealed by comparing EC1 with Ech586 and Ech703. Most virulence genes were well-conserved in Dickeya strains except Ech703. Significantly, the zms gene cluster involved in biosynthesis of zeamines, which were shown previously as key virulence determinants, is present in D. zeae strains isolated from rice, and some D. solani strains, but absent in other Dickeya species and the D. zeae strains isolated from other plants or sources. In addition, a DNA fragment containing 9 genes associated with fatty acid biosynthesis was found inserted in the fli gene cluster encoding flagellar biosynthesis of strain EC1 and other two rice isolates but not in other strains. This gene cluster shares a high protein similarity to the fatty acid genes from Pantoea ananatis. CONLUSION: Our findings delineate the genetic background of D. zeae EC1, which infects both dicotyledons and monocotyledons, and suggest that D. zeae strains isolated from rice could be grouped into a distinct pathovar, i.e., D. zeae subsp. oryzae. In addition, the results of this study also unveiled that the zms gene cluster presented in the genomes of D. zeae rice isolates and D. solani strains, and the fatty acid genes inserted in the fli gene cluster of strain EC1 were likely derived from horizontal gene transfer during later stage of bacterial evolution.


Assuntos
Enterobacteriaceae/genética , Genoma Bacteriano , Genômica , Doenças das Plantas/genética , Sequência de Bases , Mapeamento Cromossômico , Enterobacteriaceae/patogenicidade , Macrolídeos/metabolismo , Oryza/genética , Oryza/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Poliaminas/metabolismo
7.
PLoS One ; 9(12): e116047, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25541733

RESUMO

Dickeya zeae strain EC1 was recently shown to produce a new type of phytotoxins designated as zeamine and zeamine II, which are potent wide-spectrum antibiotics against Gram-positive and Gram-negative bacterial pathogens, suggesting their promising potential as clinical medicines. In this study, the optimized medium composition and culture conditions for biosynthesis of novel antibiotics zeamines have been established by using response surface methodology, largely increasing the yield of zeamines from original about 7.35 µg · mL(-1) in minimal medium to about 150 µg · mL(-1) in LS5 medium. The study identified the major factors contributing to zeamines production, which include nitrate, sucrose, asparaginate, mineral elements Mg2+ and K+, and optimized amount of phosphate. In addition, the results showed that overexpression of zmsK in D. zeae strain EC1 could further increase zeamines yield to about 180 µg · mL(-1) in LS5 medium. The findings from this study could facilitate further characterization and utilization of these two novel antibiotics, and also provide useful clues for understanding the regulatory mechanisms that govern D. zeae virulence.


Assuntos
Antibacterianos/metabolismo , Enterobacteriaceae/metabolismo , Macrolídeos/metabolismo , Poliaminas/metabolismo , Técnicas de Cultura de Células , Fermentação , Microbiologia Industrial
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