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1.
Nutrients ; 15(18)2023 Sep 19.
Article in English | MEDLINE | ID: mdl-37764837

ABSTRACT

Moderate red wine intake has been associated with lower cardiovascular mortality, due in part to the intake of polyphenols and anthocyanins, whose content can vary from varietal and year of harvest. This study assessed the vascular effects in response to a single intake of 2015 and 2018 Zweigelt red wines from Hokkaido, Japan. Healthy men were randomly assigned to consume 240 mL each of a red wine, or a sparkling white grape juice as a control in a randomized three-arm cross-over design with a 7 day washout between arms. The augmentation index (AI; a measure of arterial stiffness) and AI at 75 beats/min (AI75), reactive hyperemia index, systolic and diastolic blood pressure (SBP and DBP, respectively), and platelet reactivity were assessed at baseline and two and four hours after each beverage intake. Changes from the baseline were analyzed using a linear mixed model. Significant treatment effects (p = 0.02) were observed, with AI 13% lower after the intake of the 2015 or 2018 vintages compared to the control. Intake of the 2018 vintage reduced SBP and DBP (-4.1 mmHg and -5.6 mmHg, respectively; p = 0.02) compared to the 2015 wine and the control drink. The amount of hydroxytyrosol in the 2018 wine was almost twice the amount as in the 2015 wine, which may help explain the variable blood pressure results. Future studies exploring the vascular effects of the same red wine from different vintage years and different phenolic profiles are warranted.

2.
Front Plant Sci ; 14: 1198710, 2023.
Article in English | MEDLINE | ID: mdl-37457349

ABSTRACT

Grapevine crown gall (GCG) is a significant bacterial disease caused by tumorigenic Allorhizobium vitis (TAV) and is prevalent worldwide. TAV infects grapevines through wounds such as freezing injuries. Although grapevines typically avoid being wounded under snow cover, GCG occurs in many commercial vineyards in snowy regions. This study investigated the TAV population in GCG gall tissues, grapevine skins, and snow on grapevine skins from six infected vineyards located in Hokkaido, Japan, an area known for heavy snowfall. TAV was isolated not only from gall tissues but also from skins and snow on skins throughout the year. Hierarchical Bayesian model (HBM) analysis revealed that the number of TAV cells in gall tissues was affected by cultivar and low temperature, while those in skins were affected by location and low temperature. Additionally, Bayesian changepoint detection (BCD) showed that the number of TAV cells in gall and skin tissues increased during winter, including the snowfall season. Furthermore, the TAV population in grapevine skins under the snow was significantly higher than those above the snow, indicating that TAV under the snow is protected by the snow and can survive well during the snowfall season. This study highlights the ability of TAV to overwinter on/in galls and skins under the snow and act as inoculum for the next season.

3.
Food Chem ; 414: 135740, 2023 Jul 15.
Article in English | MEDLINE | ID: mdl-36842203

ABSTRACT

Redox species in wine are altered by pH and some wines are easily degraded due to oxidation and sulfur dioxide (SO2) reduction. There is a need for quick, easy, simple, and economical methodologies for pH and wine-oxidized products (acetaldehyde) analysis. This study aimed to measure pH and degradation of wines that were electrochemically analyzed using polyaniline (PANI) sensor. Gas chromatography (GC) and fourier transform infrared spectrometer (FT-IR) were also used. Electrochemical analysis showed that oxidation was accelerated and peak currents (Ip,a) and potentials (Ep,a) shifted to negative direction due to acetaldehyde formation. PANI sensor achieved a limit of detection (LOD) of 7 × 10-1 ppm and a sensitivity of 5.20 µA ppm-1 cm-2. Acetaldehyde formation was confirmed by GC (30%) and FT-IR spectra at 1647 cm-1 to the CO vibration of aldehyde. These results suggested that acetaldehyde degraded the taste of wine after remaining open.


Subject(s)
Wine , Wine/analysis , Spectroscopy, Fourier Transform Infrared , Oxidation-Reduction , Acetaldehyde/analysis , Oxidative Stress
4.
Curr Microbiol ; 79(8): 217, 2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35704076

ABSTRACT

Gentamicin is an important antibiotic for the treatment of opportunistic infections in the clinical field. Gentamicin-resistant bacteria have been detected in livestock animals and can be transmitted to humans through the food supply or direct contact. We have previously revealed that gentamicin-resistant Escherichia coli are distributed at a comparatively high rate from beef cattle in Japan, but few studies have focused on the molecular epidemiology of gentamicin-resistant bacteria. To understand these bacteria, this study examined the prevalence of various gentamicin resistance genes in gentamicin-resistant E. coli isolates from beef cattle feces. Of the 239 gentamicin-resistant E. coli isolates, the presence of the aacC2, aadB, or aac(3)-VIa genes was confirmed in 147, 84, and 8 isolates, respectively. All aac(3)-VIa-harboring isolates had an MIC value of 64 µg/mL for gentamicin and exhibited resistance to 11 antibiotic agents. An analysis of the representative aac(3)-VIa-harboring E. coli strain GC1-3-GR-4 revealed that the aac(3)-VIa gene was present on the IncA/C plasmid together with the aadA and blaCMY genes. Furthermore, the upstream region of the aac(3)-VIa gene contained the aadA gene and the class 1 integron-integrase gene (intI1). The aac(3)-VIa gene was detected for the first time in Japan and is expected to be able to transfer between bacteria via the IncA/C plasmid and integron. These results reveal the expansion of the distribution or diversity of gentamicin resistance genes in Japan.


Subject(s)
Escherichia coli Infections , Escherichia coli , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cattle , Escherichia coli/genetics , Escherichia coli Infections/drug therapy , Escherichia coli Infections/epidemiology , Escherichia coli Infections/veterinary , Feces/microbiology , Gentamicins/pharmacology , Japan/epidemiology , Microbial Sensitivity Tests , Prevalence
5.
Life (Basel) ; 11(11)2021 Nov 19.
Article in English | MEDLINE | ID: mdl-34833141

ABSTRACT

Crown gall is a globally distributed and economically important disease of grapevine and other important crop plants. The causal agent of grapevine crown gall is tumorigenic Allorhizobium vitis (Ti) strains that harbor a tumor-inducing plasmid (pTi). The epidemic of grapevine crown gall has not been widely elucidated. In this study, we investigated the genetic diversity of 89 strains of Ti and nonpathogenic A. vitis to clarify their molecular epidemiology. Multi-locus sequence analysis (MLSA) of the partial nucleotide sequences of pyrG, recA, and rpoD was performed for molecular typing of A. vitis strains isolated from grapevines with crown gall symptoms grown in 30 different vineyards, five different countries, mainly in Japan, and seven genomic groups A to F were obtained. The results of MLSA and logistic regression indicated that the population of genetic group A was significantly related to a range of prefectures and that the epidemic of group A strains originated mainly in Hokkaido in Japan through soil infection. Moreover, group E strains could have been transported by infected nursery stocks. In conclusion, this study indicates that both soil infection and transporting of infected nursery stocks are working as infection source in Hokkaido.

6.
Biosci Biotechnol Biochem ; 85(10): 2217-2220, 2021 Sep 22.
Article in English | MEDLINE | ID: mdl-34387309

ABSTRACT

In phytopathogenic fungi, a mutation in the avirulence gene can lead to the breakdown of resistance in the host plant. The nucleotide sequences of the AVR-Pik locus in the strain Ina168 and its spontaneous mutant Ina168m95-5 of Pyricularia oryzae were determined. An AVR-Pik spontaneous deletion mechanism of Ina168m95-5, including multiple homologous recombination events involving repetitive transposable elements, is proposed.


Subject(s)
Ascomycota , Disease Resistance , Magnaporthe , Oryza , Plant Diseases
7.
Microbes Environ ; 35(4)2020.
Article in English | MEDLINE | ID: mdl-33177277

ABSTRACT

Bacterial cell shapes may be altered by the cell cycle, nutrient availability, environmental stress, and interactions with other organisms. The bean bug Riptortus pedestris possesses a symbiotic bacterium, Burkholderia insecticola, in its midgut crypts. This symbiont is a typical rod-shaped bacterium under in vitro culture conditions, but changes to a spherical shape inside the gut symbiotic organ of the host insect, suggesting the induction of morphological alterations in B. insecticola by host factors. The present study revealed that a deletion mutant of a peptidoglycan amidase gene (amiC), showing a filamentous chain form in vitro, adapted a swollen L-form-like cell shape in midgut crypts. Spatiotemporal observations of the ΔamiC mutant in midgut crypts revealed the induction of swollen cells, particularly prior to the molting of insects. To elucidate the mechanisms underlying in vivo-specific morphological alterations, the symbiont was cultured under 13 different conditions and its cell shape was examined. Swollen cells, similar to symbiont cells in midgut crypts, were induced when the mutant was treated with fosfomycin, an inhibitor of peptidoglycan precursor biosynthesis. Collectively, these results strongly suggest that the Burkholderia symbiont in midgut crypts is under the control of the host insect via a cell wall-attacking agent.


Subject(s)
Amidohydrolases/genetics , Bacterial Proteins/genetics , Burkholderia/cytology , Burkholderia/enzymology , Peptidoglycan/metabolism , Adaptation, Physiological , Amidohydrolases/metabolism , Animals , Bacterial Proteins/metabolism , Burkholderia/genetics , Burkholderia/physiology , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/physiology , Heteroptera/microbiology , Heteroptera/physiology , Mutation , Symbiosis
8.
Biosci Biotechnol Biochem ; 84(11): 2401-2404, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32729391

ABSTRACT

A novel homolog of laeA, a global regulatory gene in filamentous fungi, was identified from Pyricularia oryzae. A deletion mutant of the homolog (PoLAE2) exhibited lowered intracellular cAMP levels, and decreased appressorium formation on non-host surface; the decrease was recovered using exogenous cAMP and IBMX, indicating that PoLAE2 deletion affected the cAMP signaling pathway.


Subject(s)
Ascomycota/cytology , Ascomycota/metabolism , Cyclic AMP/metabolism , Fungal Proteins/metabolism , Signal Transduction , Intracellular Space/metabolism
9.
DNA Cell Biol ; 39(9): 1730-1740, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32580635

ABSTRACT

Polyinosinic-polycytidylic acid (PIC) is a potent double-stranded RNA (dsRNA) adjuvant useful in intranasal influenza vaccination. In mice, the intensity and duration of immune responses to PIC correlated with the double-stranded chain length. A rational method to avoid PIC chain extension in PIC production is to use multiple short poly(I) molecules and one long poly(C) molecule for PIC assembly. In this study, we elucidate that a newly developed uPIC100-400 molecule comprising multiple 0.1 kb poly(I) molecules and one 0.4 kb poly(C) molecule effectively enhanced the immune responses in mice, by preventing the challenged viral propagation and inducing hemagglutinin-specific IgA, after intranasal A(H1N1)pdm09 influenza vaccination. Reduced intraperitoneal toxicity of PIC prepared with multiple short poly(I) molecules in mice indicates the widened effective range of uPIC100-400 as an adjuvant. In contrast to uPIC100-400, the PIC molecule comprising multiple 0.05 kb poly(I) molecules failed to elicit mouse mucosal immunity. These results were consistent with TLR3 response but not retinoic acid inducible gene I (RIG-I)-like receptor response in the cell assays, which suggests that the adjuvant effect of PIC in mouse intranasal immunization depends on TLR3 signaling. In conclusion, the double-stranded PIC with reduced toxicity developed in this study would contribute to the development of PIC-adjuvanted vaccines.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Interferon Inducers/therapeutic use , Orthomyxoviridae Infections/immunology , Poly I-C/therapeutic use , Toll-Like Receptor 3/metabolism , Vaccination/methods , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/adverse effects , Animals , Cells, Cultured , Female , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Immunoglobulin A/immunology , Influenza Vaccines/immunology , Interferon Inducers/administration & dosage , Interferon Inducers/adverse effects , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Orthomyxoviridae Infections/prevention & control , Poly I-C/administration & dosage , Poly I-C/adverse effects , Signal Transduction
10.
Microbiol Resour Announc ; 9(20)2020 May 14.
Article in English | MEDLINE | ID: mdl-32409534

ABSTRACT

Escherichia coli is a common reservoir for antimicrobial resistance genes that can be easily transformed to possess multidrug resistance through plasmid transfer. To understand multidrug resistance plasmids, we report the plasmid sequences of four large plasmids carrying a number of genes related to antimicrobial resistance that were found in E. coli strains isolated from beef cattle.

11.
Microbes Environ ; 34(1): 95-98, 2019 Mar 30.
Article in English | MEDLINE | ID: mdl-30773516

ABSTRACT

Supplementation with conductive magnetite particles promoted methanogenic acetate degradation by microbial communities enriched from the production water of a high-temperature petroleum reservoir. A microbial community analysis revealed that Petrothermobacter spp. (phylum Deferribacteres), known as thermophilic Fe(III) reducers, predominated in the magnetite-supplemented enrichment, whereas other types of Fe(III) reducers, such as Thermincola spp. and Thermotoga spp., were dominant under ferrihydrite-reducing conditions. These results suggest that magnetite induced interspecies electron transfer via electric currents through conductive particles between Petrothermobacter spp. and methanogens. This is the first evidence for possible electric syntrophy in high-temperature subsurface environments.


Subject(s)
Acetates/metabolism , Ferrosoferric Oxide/chemistry , Methane/biosynthesis , Microbiota , Petroleum/microbiology , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/metabolism , Electron Transport , Euryarchaeota/metabolism , Ferric Compounds/chemistry , Ferrosoferric Oxide/antagonists & inhibitors , Hot Temperature , Oxidation-Reduction , Petroleum/metabolism , RNA, Ribosomal, 16S/genetics
12.
ISME J ; 13(6): 1469-1483, 2019 06.
Article in English | MEDLINE | ID: mdl-30742016

ABSTRACT

In the symbiosis of the bean bug Riptortus pedestris with Burkholderia insecticola, the bacteria occupy an exclusive niche in the insect midgut and favor insect development and reproduction. In order to understand how the symbiotic bacteria stably colonize the midgut crypts and which services they provide to the host, we compared the cytology, physiology, and transcriptomics of free-living and midgut-colonizing B. insecticola. The analyses revealed that midgut-colonizing bacteria were smaller in size and had lower DNA content, they had increased stress sensitivity, lost motility, and an altered cell surface. Transcriptomics revealed what kinds of nutrients are provided by the bean bug to the Burkholderia symbiont. Transporters and metabolic pathways of diverse sugars such as rhamnose and ribose, and sulfur compounds like sulfate and taurine were upregulated in the midgut-colonizing symbionts. Moreover, pathways enabling the assimilation of insect nitrogen wastes, i.e. allantoin and urea, were also upregulated. The data further suggested that the midgut-colonizing symbionts produced all essential amino acids and B vitamins, some of which are scarce in the soybean food of the host insect. Together, these findings suggest that the Burkholderia symbiont is fed with specific nutrients and also recycles host metabolic wastes in the insect gut, and in return, the bacterial symbiont provides the host with essential nutrients limited in the insect food, contributing to the rapid growth and enhanced reproduction of the bean bug host.


Subject(s)
Bacterial Proteins/genetics , Burkholderia/physiology , Heteroptera/microbiology , Animals , Bacterial Proteins/metabolism , Burkholderia/classification , Burkholderia/genetics , Burkholderia/isolation & purification , Culture Media/metabolism , Gastrointestinal Tract/microbiology , Heteroptera/growth & development , Heteroptera/physiology , Symbiosis/physiology , Transcriptome
13.
Biosci Biotechnol Biochem ; 82(11): 1889-1901, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30079840

ABSTRACT

Polyinosinic-polycytidylic acid (PIC), a double-stranded RNA that induces innate immunity in mammals, is a candidate immunopotentiator for pharmaceuticals. The potency and adverse effects of PIC are strongly correlated with the nucleotide length, and the inability to precisely control the length in PIC production limits its practical use. Length extension during the annealing process is the major factor underlying the lack of control, but tuning the annealing conditions is insufficient to resolve this issue. In this study, we developed a novel method to produce accurate nucleotide length PIC at an industrial scale. The length extension was significantly suppressed by the assembly of multiple short polyinosinic acid molecules with one long polycytidylic acid molecule. A newly developed PIC, uPIC100-400, demonstrated a reproducible length and better storage stability than that of corresponding evenly structured PIC. Human dsRNA receptors exhibited equivalent responsiveness to uPIC100-400 and the evenly structured PIC with the same length.


Subject(s)
Nucleic Acid Conformation , Nucleotides/chemistry , Poly I-C/chemistry , Poly I-C/chemical synthesis , Cell Line , Hot Temperature , Humans , Immunity, Innate , Poly C/chemistry , Poly I/chemistry , RNA, Double-Stranded/chemistry
14.
Appl Environ Microbiol ; 84(19)2018 10 01.
Article in English | MEDLINE | ID: mdl-30030229

ABSTRACT

Most microorganisms living in the environment have yet to be cultured, owing at least in part to their slow and poor propagation properties and susceptibility to oxidative stress. Our previous studies demonstrated that a simple modification in the preparation of agar media, i.e., autoclaving the phosphate and agar separately (termed "PS" medium), can greatly improve the culturability of microorganisms by mitigating oxidative stress compared with the use of "PT" medium (autoclaving the phosphate and agar together). Here, we attempted to isolate phylogenetically novel bacteria by combining PS medium with prolonged cultivation. After inoculation with forest soil or pond sediment samples, significantly more colonies appeared on PS medium than on PT medium. A total of 98 and 74 colonies that emerged after more than 7 days of cultivation were isolated as slow growers from PS and PT media, respectively. Sequencing analysis of their 16S rRNA genes revealed that the slow growers recovered from PS medium included more phylogenetically novel bacteria than those from PT medium, including a strain that could be classified into a novel order in the class Alphaproteobacteria Further physiological analysis of representative strains showed that they were actually slow and poor growers and formed small but visible colonies only on PS medium. This study demonstrates that the culturability of previously uncultured bacteria can be improved by using an isolation strategy that combines a simple modification in medium preparation with an extended incubation time.IMPORTANCE Most microbial species inhabiting natural environments have not yet been isolated. One of the serious issues preventing their isolation is intrinsically slow and/or poor growth. Moreover, these slow and/or poor growers are likely to be highly sensitive to environmental stresses, especially oxidative stress. We reported previously that interaction between agar and phosphate during autoclave sterilization generates hydrogen peroxide, which adversely affects the culturability of environmental microorganisms, in particular, slow-growing organisms vulnerable to oxidative stress. In this study, we successfully isolated many slow-growing bacterial strains with phylogenetic novelty by simply modifying their cultivation on agar plates, i.e., autoclaving the phosphate and agar separately. The current limited repertoire of culture techniques still has room for improvement in the isolation of microorganisms previously considered unculturable.


Subject(s)
Bacteria/growth & development , Bacteria/isolation & purification , Colony Count, Microbial/methods , Culture Media/metabolism , Agar , Bacteria/classification , Bacteria/genetics , Colony Count, Microbial/instrumentation , Culture Media/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Phylogeny , Ponds/microbiology , RNA, Ribosomal, 16S/genetics , Soil Microbiology
15.
Int J Syst Evol Microbiol ; 68(7): 2370-2374, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29863457

ABSTRACT

A Gram-negative, aerobic, rod-shaped, non-spore-forming, motile bacterium, designated strain RPE64T, was isolated from the gut symbiotic organ of the bean bug Riptortus pedestris, collected in Tsukuba, Japan, in 2007. 16S rRNA gene sequencing showed that this strain belongs to the Burkholderia glathei clade, exhibiting the highest sequence similarity to Burkholderia peredens LMG 29314T (100 %), Burkholderia turbans LMG 29316T (99.52 %) and Burkholderia ptereochthonis LMG 29326T (99.04 %). Phylogenomic analyses based on 107 single-copy core genes and Genome blast Distance Phylogeny confirmed B. peredens LMG 29314T, B. ptereochthonis LMG 29326T and several uncultivated, endophytic Burkholderia species as its nearest phylogenetic neighbours. Digital DNA-DNA hybridization experiments unambiguously demonstrated that strain RPE64T represents a novel species in this lineage. The G+C content of its genome was 63.2 mol%. The isoprenoid quinone was ubiquinone 8 and the predominant fatty acid components were C16 : 0, C18 : 1ω7c and C17 : 0 cyclo. The absence of nitrate reduction and the capacity to grow at pH 8 clearly differentiated strain RPE64T from related Burkholderia species. Based on these genotypic and phenotypic characteristics, strain RPE64T is classified as representing a novel species of the genus Burkholderia, for which the name Burkholderia insecticola sp. nov. is proposed. The type strain is RPE64T (=NCIMB 15023T=JCM 31142T).


Subject(s)
Burkholderia/classification , Digestive System/microbiology , Heteroptera/microbiology , Phylogeny , Animals , Bacterial Typing Techniques , Base Composition , Burkholderia/genetics , Burkholderia/isolation & purification , DNA, Bacterial/genetics , Fatty Acids/chemistry , Japan , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Symbiosis , Ubiquinone/chemistry
16.
J Microbiol ; 55(9): 720-729, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28865074

ABSTRACT

The microbiota of lactic acid bacteria (LAB) in thirty-five samples of Miang, a traditional fermented tea leaf product, collected from twenty-two different regions of eight provinces in upper northern Thailand was revealed through the culture-dependent technique. A total of 311 presumptive LAB strains were isolated and subjected to clustering analysis based on repetitive genomic element-PCR (rep-PCR) fingerprinting profiles. The majority of the strains belonged to the Lactobacillus genera with an overwhelming predominance of the Lb. plantarum group. Further studies of species-specific PCR showed that 201 of 252 isolates in the Lb. plantarum group were Lb. plantarum which were thus considered as the predominant LAB in Miang, while the other 51 isolates belonged to Lb. pentosus. In contrast to Lb. plantarum, there is a lack of information on the tannase gene and the tea tannin-tolerant ability of Lb. pentosus. Of the 51 Lb. pentosus isolates, 33 were found to harbor the genes encoding tannase and shared 93-99% amino acid identity with tannase obtained from Lb. pentosus ATCC 8041T. Among 33 tannase gene-positive isolates, 23 isolates exhibited high tannin- tolerant capabilities when cultivated on de Man Rogosa and Sharpe agar-containing bromocresol purple (0.02 g/L, MRS-BCP) supplemented with 20% (v/v) crude tea extract, which corresponded to 2.5% (w/v) tannins. These Lb. pentosus isolates with high tannin-tolerant capacity are expected to be the high potential strains for functional tannase production involved in Miang fermentation as they will bring about certain benefits and could be used to improve the fermentation of tea products.


Subject(s)
Fermented Foods/microbiology , Genetic Variation , Lactobacillales/drug effects , Lactobacillales/isolation & purification , Tannins/pharmacology , Tea/microbiology , Bioreactors , Carboxylic Ester Hydrolases/genetics , Fermentation , Lactobacillales/classification , Lactobacillales/genetics , Phylogeny , Plant Leaves/metabolism , Plant Leaves/microbiology , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Tea/chemistry , Thailand
17.
Sci Rep ; 7(1): 1965, 2017 05 16.
Article in English | MEDLINE | ID: mdl-28512321

ABSTRACT

Biological incorporation of cesium ions (Cs+) has recently attracted significant attention in terms of the possible applications for bioremediation of radiocesium and their significant roles in biogeochemical cycling. Although high concentrations of Cs+ exhibit cytotoxicity on microorganisms, there are a few reports on the promotive effects of Cs+ on microbial growth under K+-deficient conditions. However, whether this growth-promoting effect is a common phenomenon remains uncertain, and direct correlation between growth promotion and Cs+ uptake abilities has not been confirmed yet. Here, we validated the growth promotive effects of Cs+ uptake under K+-deficient conditions using an Escherichia coli strain with an inducible expression of the Kup K+ transporter that has nonspecific Cs+ transport activities (strain kup-IE). The strain kup-IE exhibited superior growth under the Cs+-supplemented and K+-deficient conditions compared to the wild type and the kup null strains. The intracellular Cs+ levels were significantly higher in strain kup-IE than in the other strains, and were well correlated with their growth yields. Furthermore, induction levels of the kup gene, intracellular Cs+ concentrations, and the growth stimulation by Cs+ also correlated positively. These results clearly demonstrated that Cs+ incorporation via Kup transporter restores growth defects of E. coli under K+-deficient conditions.


Subject(s)
Cesium/metabolism , Escherichia coli Proteins/metabolism , Escherichia coli/physiology , Potassium/metabolism , Biological Transport , Cesium/toxicity , Escherichia coli/drug effects , Escherichia coli Proteins/genetics , Gene Expression Regulation, Bacterial , Mutation , Potassium Deficiency/metabolism
18.
Mol Plant Pathol ; 18(8): 1138-1149, 2017 10.
Article in English | MEDLINE | ID: mdl-27528510

ABSTRACT

In order to facilitate infection, the rice blast pathogen Magnaporthe oryzae secretes an abundance of proteins, including avirulence effectors, to diminish its host's defences. Avirulence effectors are recognized by host resistance proteins and trigger the host's hypersensitive response, which is a rapid and effective form of innate plant immunity. An understanding of the underlying molecular mechanisms of such interactions is crucial for the development of strategies to control disease. However, the expression and secretion of certain effector proteins, such as AVR-Pia, have yet to be reported. Reverse transcription-polymerase chain reaction (RT-PCR) revealed that AVR-Pia was only expressed during infection. Fluorescently labelled AVR-Pia indicated that AVR-Pia expression was induced during appressorial differentiation in the cells of both rice and onion, as well as in a penetration-deficient (Δpls1) mutant capable of developing melanized appressoria, but unable to penetrate host cells, suggesting that AVR-Pia expression is independent of fungal penetration. Using live-cell imaging, we also documented the co-localization of green fluorescent protein (GFP)-labelled AVR-Pia and monomeric red fluorescent protein (mRFP)-labelled PWL2, which indicates that AVR-Pia accumulates in biotrophic interfacial complexes before being delivered to the plant cytosol. Together, these results suggest that AVR-Pia is a cytoplasmic effector that is expressed at the onset of appressorial differentiation and is translocated to the biotrophic interfacial complex, and then into the host's cytoplasm.


Subject(s)
Fungal Proteins/metabolism , Genes, Reporter , Magnaporthe/metabolism , Magnaporthe/pathogenicity , Virulence Factors/metabolism , Cell Differentiation/genetics , Cytoplasm/metabolism , Fluorescence , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Genetic Vectors/metabolism , Green Fluorescent Proteins/metabolism , Magnaporthe/genetics , Oryza/microbiology , Plant Cells/metabolism , Promoter Regions, Genetic/genetics , Protein Biosynthesis , Protein Transport , Time Factors
19.
Microbes Environ ; 30(4): 321-9, 2015.
Article in English | MEDLINE | ID: mdl-26657305

ABSTRACT

A number of phytophagous stinkbugs (order Heteroptera: infraorder Pentatomomorpha) harbor symbiotic bacteria in a specific midgut region composed of numerous crypts. Among the five superfamilies of the infraorder Pentatomomorpha, most members of the Coreoidea and Lygaeoidea are associated with a specific group of the genus Burkholderia, called the "stinkbug-associated beneficial and environmental (SBE)" group, which is not vertically transmitted, but acquired from the environment every host generation. A recent study reported that, in addition to these two stinkbug groups, the family Largidae of the superfamily Pyrrhocoroidea also possesses a Burkholderia symbiont. Despite this recent finding, the phylogenetic position and biological nature of Burkholderia associated with Largidae remains unclear. Based on the combined results of fluorescence in situ hybridization, cloning analysis, Illumina deep sequencing, and egg inspections by diagnostic PCR, we herein demonstrate that the largid species are consistently associated with the "plant-associated beneficial and environmental (PBE)" group of Burkholderia, which are phylogenetically distinct from the SBE group, and that they maintain symbiosis through the environmental acquisition of the bacteria. Since the superfamilies Coreoidea, Lygaeoidea, and Pyrrhocoroidea are monophyletic in the infraorder Pentatomomorpha, it is plausible that the symbiotic association with Burkholderia evolved at the common ancestor of the three superfamilies. However, the results of this study strongly suggest that a dynamic transition from the PBE to SBE group, or vice versa, occurred in the course of stinkbug evolution.


Subject(s)
Burkholderia/isolation & purification , Burkholderia/physiology , Heteroptera/microbiology , Symbiosis , Animals , Cloning, Molecular , Gastrointestinal Tract/microbiology , High-Throughput Nucleotide Sequencing , In Situ Hybridization, Fluorescence , Polymerase Chain Reaction , Sequence Analysis, DNA
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