【Objective】This study aimed to establish a quintuple PCR method for rapid and simultaneous detection of Ralstonia solanacearum,Fusarium spp.,Pectobacterium spp.,Enterobacter spp.,and Pythium spp.,which provided tech...【Objective】This study aimed to establish a quintuple PCR method for rapid and simultaneous detection of Ralstonia solanacearum,Fusarium spp.,Pectobacterium spp.,Enterobacter spp.,and Pythium spp.,which provided technical support for early diagnosis of various soil-borne diseases on ginger.【Method】For five types of soil-borne pathogens causing ginger bacterial wilt and rhizome rot,specific primer combinations were designed and screened,the optimal quintuple reaction system was established by exploring optimal primer concentrations,annealing temperature,and sensitivity,and was applied to detect field plant samples to verify its utility.【Result】Specific primers pairs Rs1F/Rs1R,En1F/En1R,and Py1F/Py1R were designed according to flic gene of Ralstonia solanacearum,rpoB gene of Enterobacter spp.,and 18S rDNA of Pythium spp.,and combined with reported Fusarium spp.specific primers Fu3/Fu4 and specific primers 23SPecF/23SPecR of Pectobacterium spp.,a quintuple PCR reaction system for ginger soil-borne pathogens has been established(25.00μL):above primer dosage was 1.20,0.20,0.60,1.60,and 0.15μL respectively;2×PCR Mix 12.50μL;DNA templates of different pathogens were 1.00μL each;added ddH_(2)O to 25.00μL.Annealing temperature was optimized to 55.4℃.The specific fragments with sizes of 516,370,266,207,and 159 bp could be amplified simultaneously in the established quintuple PCR system,and the detection limit of this system for Ralstonia solanacearum,Enterobacter spp.and Pythium spp.reached 10^(-1)pg/μL,for Fusarium spp.and Pectobacterium spp.was 1 pg/μL,and for detecting five pathogens simultaneously was 10^(3)pg/μL.The multiplex PCR system established in this study could successfully detect the diseased plant samples from the field.【Conclusion】The quintuple PCR system established is able to rapid ly and accurately detect Ralstonia solanacearum,Fusarium spp.,Pectobacterium spp.,Enterobacter spp.,and Pythium spp.,which provides a useful tool for timely diagnosis and epidemic monitoring of various soil-borne diseases of ginger.展开更多
This study aimed to clarify the pathogen composition,biological characteristics,infection patterns,and effective control agents for panicle blight of rice in Heilongjiang Province.Diseased panicles were collected from...This study aimed to clarify the pathogen composition,biological characteristics,infection patterns,and effective control agents for panicle blight of rice in Heilongjiang Province.Diseased panicles were collected from different rice-growing areas in Heilongjiang Province and subjected to tissue isolation,pathogenicity tests,morphological observation,and molecular identification.The primary pathogens identified were Fusarium graminearum,Alternaria alternata and Nigrospora oryzae.The biological characteristics of these three pathogens were systematically investigated.Pathogenicity assays revealed that F.graminearum exhibited the strongest pathogenicity,followed by A.alternata,while N.oryzae was the weakest.In vitro toxicity tests screened highly effective fungicides:75%trifloxystrobin-tebuconazole showed the best inhibitory effect against F.graminearum(EC50=0.0140μg·mL^(-1));30%tebuconazole-azoxystrobin was the most effective against A.alternata(EC50=0.0060μg·mL^(-1))and N.oryzae(EC50=0.0310μg·mL^(-1)).展开更多
Verticillium wilt,caused by the notorious fungal pathogen Verticillium dahliae,is one of the main limiting factors for cotton production.Due to the stable dormant structure microsclerotia,long-term variability and co-...Verticillium wilt,caused by the notorious fungal pathogen Verticillium dahliae,is one of the main limiting factors for cotton production.Due to the stable dormant structure microsclerotia,long-term variability and co-evolution with host plant,its pathogenicity mechanism is very complicated,and the interaction mechanism between pathogen and host plant is also unclear.So identification and functional analysis of the genes involved in the pathogenicity or virulence of this fungus will benefit to uncover the molecular pathogenic mechanism of V.dahliae.In this review,many multifunction genes covering microsclerotia development,pathogen infection,effector proteins,transcription factors,horizontal gene transfer and trans-kingdom RNA silencing have been summarized to provide a theoretical basis to deep understand the molecular pathogenicity mechanism of V.dahliae and promote to effectively control Verticillium wilt.Furtherly,these pathogenicity-related genes may be considered as targets for effective control of Verticillium wilt in cotton.展开更多
Identification of powdery mildew pathogens on melon（Cucumis melo） is important for melon breeding and diseaseresistant germplasm selection. In this study, a powdery mildew pathogen that infected melon plants in Heil...Identification of powdery mildew pathogens on melon（Cucumis melo） is important for melon breeding and diseaseresistant germplasm selection. In this study, a powdery mildew pathogen that infected melon plants in Heilongjiang Province, China, was investigated in terms of host identification, morphological characteristics and phylogenetic relationships. The morphological characteristics of the pathogen were observed at five phases in the life cycle： germinating conidia, primary germ tube, hyphae, conidiophores, and colonization. The conidia were elliptical, colorless, catenulate, and the average length was 29.07 μm and average width was 17.82 μm. One ascus and eight ascospores were produced. DNA was extracted from 0.01 g conidiophores from a strain of powdery mildew pathogen that infected melon. ITS ribosomal DNA region（524 bp） was amplified with the universal ITS1 and ITS4 primers. The nucleotide sequence showed 100% similarity with ITS sequences for three Podosphaera fusca strains obtained from the GenBank database. The identity of the pathogen was confirmed as Sphaerotheca fuliginea. International standard differential hosts were used to identify S. fuliginea strain as 2F race. These results supported the notion that Podosphaera fusca was a synonym of S. fuliginea.展开更多
Cotton disea ses represent a major challenge to cotton growth.Cloning of a cotton pathogen re-sponse gene and promoter is of great importance to improve disease resistance.In this study,a full length CC-NBS-LRRgene(GH...Cotton disea ses represent a major challenge to cotton growth.Cloning of a cotton pathogen re-sponse gene and promoter is of great importance to improve disease resistance.In this study,a full length CC-NBS-LRRgene(GHNBS)and its 5L flanking sequence have been cloned by race and tail PCR and further studied.The entire coding region is 2583 bp and enco des a polypeptide of 861 a mino acids with 28%maximum homology to an R gene of Arabi dopsis depo sited in the GenBank.Semi quantitativeRT-PCR showed thatGHNBS was expressed in floral buds,petals,phloem,root s,and leaves,and it has a greater exp ression pattern in roots and leaves.展开更多
Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research s...Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research strategies have been applied to identify the main genes and compounds involved in the antagonist-plant-pathogen three-way interaction. During mycoparasitism, signals from the host fungus are recognised by Trichoderma, stimulating antifungal activities that are accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Interestingly some morphological changes appeared highly conserved in the strategy of pathogenicity within the fungal world, i.e. the formation of appressoria as well as the secretion of hydrolytic enzymes seem to be general mechanisms of attack both for plant pathogens and mycoparasitic antagonists. This knowledge is being used to identify receptors and key components of signalling pathways involved in fungus-fungus interaction. For this purpose we have cloned the first genes (tmk1, tga1, tga3) from T. atroviride showing a high similarity to MAP kinase and G protein subunits (see abstract by Zeilinger et al.), which have been found to have an important role in pathogenicity by Magnaporthe grisea. To identify the function and involvement of these factors in mycoparasitism by T. atroviride, tmk1, tga1, tga3 disruptant strains were produced. The knock-out mutants were tested by in vivo biocontrol assays for their ability to inhibit soil and foliar plant pathogens such as Rhizoctonia solani, Pythium ultimum and Botrytis cinerea . Disruption of these genes corresponded to a complete loss of biocontrol ability, suggesting a significant role in mycoparasitism. In particular, it has been suggested that tga3 regulates the expression of chitinase-encoding genes, the secretion of the corresponding enzymes and the process of conidiation. Comparative proteome analysis of wild type and disruptants supported this hypothesis, and indicated many changes in the protein profiles of T. atroviride in different interaction conditions with plants and pathogenic hosts.展开更多
[Objectives]Lotus(Nelumbo nucifera Gaertn)is an economically important aquatic plant in China.Fungal disease is a serious problem in lotus cultivation.In this study,the pathogenic fungi on lotus in Nanchang City were ...[Objectives]Lotus(Nelumbo nucifera Gaertn)is an economically important aquatic plant in China.Fungal disease is a serious problem in lotus cultivation.In this study,the pathogenic fungi on lotus in Nanchang City were investigated to lay the foundation for the disease control.[Methods]Lotus leaves and stems in ponds of Nanchang City were collected,the fungi on leave/stem spots were isolated and purified.Colonies morphological characters and ITS sequences were used to identify the strains.[Results]49 strains were isolated and identified to 20 species,belonging to 12 genera.[Discussion]15 species may firstly be reported on lotus in this study,i.e.,Alternaria angustiovoidea,Alternaria compacta,Alternaria ricini,Alternaria tenuissima,Arthrinium arundinis,Botryosphaeria dothidea,Curvularia spicifera,Diaporthe australiana,Diaporthe eres,Diaporthe tectonae,Epicoccum nigrum,Fusarium fujikuroi,Neofusicoccum parvum,Nigrospora sphaerica,and Phomopsis eucommii.展开更多
Several features of adenoviruses make them anattractive option as a vehicle to transfer genes intoprimary malignant neoplasms in vivo. These viruseshave low pathogenicity in humans and are notneurotoxic. In addition, ...Several features of adenoviruses make them anattractive option as a vehicle to transfer genes intoprimary malignant neoplasms in vivo. These viruseshave low pathogenicity in humans and are notneurotoxic. In addition, high titers of the virus can beachieved to allow higher levels of gene transfectionefficiency than the other vector systems. In vivotumorigenicity of G422 glioblastoma cells transfectedwith IL-2 and/or IL-3 genes decreased significantly inour privious report. In this study, recombinantadenoviruses were used to evaluate the therapeuticpotential of combined IL-2/IL-3 gene therapy in thetreatment of established subcutaneous tumor model ofG422 glioblastoma. Murine IL-2, IL-3 recombinantadenoviruses (2×10~8 pfu) were injected directly展开更多
In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrof...In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrofolate reductase thymidylate synthase derived from Toxoplasma gondii(TgDHFR-TS), were compared with that of the parental strain BJ.Results indicated that the fecundity of the transgenic parasite(TE1) was reduced at least 4 times relative to that of the BJ strain.Low dosage of the TE1 strain induced less pathogenesis in chickens than did the BJ strain,but chickens inoculated with a higher dosage of TE1 oocysts displayed severe pathogenicity and mortality as did the BJ strain.In addition,trophozoites, the first generation and the second generation meronts and merozoites,microgamonts and macrogamonts of the transgenic parasite TE1 were seen by fluorescence microscopy.More interestingly,not all four sporonts in the sporulating transgenic oocysts express YFP.These findings suggest that the expression of YFP and TgDHFR-TS genes to some extent reduced pathogenicity and reproductive potential of transgenic E.tenella.Recombination between homologous or non-homologous chromosomes occurred during zygotic meiosis in E.tenella strain TE1.展开更多
In plants,several cellular processes like celldivision,differentiation,polar growth,andresponse to pathogen attack depend on rapidreorganization of the actin cytoskeleton.Thereconstruction of actin filaments is contro...In plants,several cellular processes like celldivision,differentiation,polar growth,andresponse to pathogen attack depend on rapidreorganization of the actin cytoskeleton.Thereconstruction of actin filaments is controlled bya wide variety of actin-binding proteins,ofwhich,profilin is one of the key modulators.展开更多
The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into...The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into low-copy plasmid pWSK29 to construct the full-length cDNA clone pWSKBJC3/ w.The pWSKBJC3/w was in vitro transcribed and transfected into BHK-21 cells to rescue the virus.The results showed that the full-length cDNA clone was infectious and the virus could be rescued in BHK-21 cells.The rescued virus designated RvBJC3W was identified by RT-PCR and indirect immunofluorescence assay(IFA).The rescued virus had similar growth characteristics to its parental virus BJC3 and retained pathogenicity for mice.Our results indicate that the first infectious cDNA clone of EMCV in China has been successfully established and provides an essential tool for investigating the molecular basis of pathogenicity of EMCV.展开更多
Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16...Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16S rDNA sequence analysis. Five virulence factors were detected, then artificial infection experiment and histopathological method were carried out. These results showed that strain YER6022 was one of Y. enterocolitica family members. In addition, ail, ystb, virF, yadA and HPIint were dectected. In artificial infection experiment, with 80% mortality and 100% morbidity, injected Pelteobagrus vachellis showed red swollen of the anus, abdomen swelling and fim bleeding. There existed serious hyperaemia and edema in kidney, spleen, intestine and liver at the light microscope. Ultrastructural observation indicated that mitochondria of the liver, kidney, spleen and intestine swelled and mitochondrial cristae broke. The data had further shed light on its pathogenicity in Pelteobagrus vachelli. It would benefit for further studies on pathogenesis ofPelteobagrus vachelli infected with Y. enterocolitica.展开更多
基金National Natural Science Foundation of China(32270237)Guangxi Key Research and Development Plan Project(Guike AB21238002)Basic Scientific Research Project of Guangxi Academy of Agricultural Sciences(Guinongke 2024YP082)。
文摘【Objective】This study aimed to establish a quintuple PCR method for rapid and simultaneous detection of Ralstonia solanacearum,Fusarium spp.,Pectobacterium spp.,Enterobacter spp.,and Pythium spp.,which provided technical support for early diagnosis of various soil-borne diseases on ginger.【Method】For five types of soil-borne pathogens causing ginger bacterial wilt and rhizome rot,specific primer combinations were designed and screened,the optimal quintuple reaction system was established by exploring optimal primer concentrations,annealing temperature,and sensitivity,and was applied to detect field plant samples to verify its utility.【Result】Specific primers pairs Rs1F/Rs1R,En1F/En1R,and Py1F/Py1R were designed according to flic gene of Ralstonia solanacearum,rpoB gene of Enterobacter spp.,and 18S rDNA of Pythium spp.,and combined with reported Fusarium spp.specific primers Fu3/Fu4 and specific primers 23SPecF/23SPecR of Pectobacterium spp.,a quintuple PCR reaction system for ginger soil-borne pathogens has been established(25.00μL):above primer dosage was 1.20,0.20,0.60,1.60,and 0.15μL respectively;2×PCR Mix 12.50μL;DNA templates of different pathogens were 1.00μL each;added ddH_(2)O to 25.00μL.Annealing temperature was optimized to 55.4℃.The specific fragments with sizes of 516,370,266,207,and 159 bp could be amplified simultaneously in the established quintuple PCR system,and the detection limit of this system for Ralstonia solanacearum,Enterobacter spp.and Pythium spp.reached 10^(-1)pg/μL,for Fusarium spp.and Pectobacterium spp.was 1 pg/μL,and for detecting five pathogens simultaneously was 10^(3)pg/μL.The multiplex PCR system established in this study could successfully detect the diseased plant samples from the field.【Conclusion】The quintuple PCR system established is able to rapid ly and accurately detect Ralstonia solanacearum,Fusarium spp.,Pectobacterium spp.,Enterobacter spp.,and Pythium spp.,which provides a useful tool for timely diagnosis and epidemic monitoring of various soil-borne diseases of ginger.
基金Supported by the Green Plant Protection Project in Heilongjiang Province(2130108)the Key R&D Program Project of Heilongjiang Province(2023ZX02B0502)the Heilongjiang Province Rice Modern Agriculture Industry Technology Collaborative Innovation System Project(2025)。
文摘This study aimed to clarify the pathogen composition,biological characteristics,infection patterns,and effective control agents for panicle blight of rice in Heilongjiang Province.Diseased panicles were collected from different rice-growing areas in Heilongjiang Province and subjected to tissue isolation,pathogenicity tests,morphological observation,and molecular identification.The primary pathogens identified were Fusarium graminearum,Alternaria alternata and Nigrospora oryzae.The biological characteristics of these three pathogens were systematically investigated.Pathogenicity assays revealed that F.graminearum exhibited the strongest pathogenicity,followed by A.alternata,while N.oryzae was the weakest.In vitro toxicity tests screened highly effective fungicides:75%trifloxystrobin-tebuconazole showed the best inhibitory effect against F.graminearum(EC50=0.0140μg·mL^(-1));30%tebuconazole-azoxystrobin was the most effective against A.alternata(EC50=0.0060μg·mL^(-1))and N.oryzae(EC50=0.0310μg·mL^(-1)).
基金supported by the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural SciencesCentral Publicinterest Scientific Institution Basal Research Fund (No. 1610162021031).
文摘Verticillium wilt,caused by the notorious fungal pathogen Verticillium dahliae,is one of the main limiting factors for cotton production.Due to the stable dormant structure microsclerotia,long-term variability and co-evolution with host plant,its pathogenicity mechanism is very complicated,and the interaction mechanism between pathogen and host plant is also unclear.So identification and functional analysis of the genes involved in the pathogenicity or virulence of this fungus will benefit to uncover the molecular pathogenic mechanism of V.dahliae.In this review,many multifunction genes covering microsclerotia development,pathogen infection,effector proteins,transcription factors,horizontal gene transfer and trans-kingdom RNA silencing have been summarized to provide a theoretical basis to deep understand the molecular pathogenicity mechanism of V.dahliae and promote to effectively control Verticillium wilt.Furtherly,these pathogenicity-related genes may be considered as targets for effective control of Verticillium wilt in cotton.
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System(CARS-26-02)the National Natural Science Foundation(31000917)Heilongjiang Excellent Young Funding(JC200712)
文摘Identification of powdery mildew pathogens on melon（Cucumis melo） is important for melon breeding and diseaseresistant germplasm selection. In this study, a powdery mildew pathogen that infected melon plants in Heilongjiang Province, China, was investigated in terms of host identification, morphological characteristics and phylogenetic relationships. The morphological characteristics of the pathogen were observed at five phases in the life cycle： germinating conidia, primary germ tube, hyphae, conidiophores, and colonization. The conidia were elliptical, colorless, catenulate, and the average length was 29.07 μm and average width was 17.82 μm. One ascus and eight ascospores were produced. DNA was extracted from 0.01 g conidiophores from a strain of powdery mildew pathogen that infected melon. ITS ribosomal DNA region（524 bp） was amplified with the universal ITS1 and ITS4 primers. The nucleotide sequence showed 100% similarity with ITS sequences for three Podosphaera fusca strains obtained from the GenBank database. The identity of the pathogen was confirmed as Sphaerotheca fuliginea. International standard differential hosts were used to identify S. fuliginea strain as 2F race. These results supported the notion that Podosphaera fusca was a synonym of S. fuliginea.
文摘Cotton disea ses represent a major challenge to cotton growth.Cloning of a cotton pathogen re-sponse gene and promoter is of great importance to improve disease resistance.In this study,a full length CC-NBS-LRRgene(GHNBS)and its 5L flanking sequence have been cloned by race and tail PCR and further studied.The entire coding region is 2583 bp and enco des a polypeptide of 861 a mino acids with 28%maximum homology to an R gene of Arabi dopsis depo sited in the GenBank.Semi quantitativeRT-PCR showed thatGHNBS was expressed in floral buds,petals,phloem,root s,and leaves,and it has a greater exp ression pattern in roots and leaves.
文摘Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research strategies have been applied to identify the main genes and compounds involved in the antagonist-plant-pathogen three-way interaction. During mycoparasitism, signals from the host fungus are recognised by Trichoderma, stimulating antifungal activities that are accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Interestingly some morphological changes appeared highly conserved in the strategy of pathogenicity within the fungal world, i.e. the formation of appressoria as well as the secretion of hydrolytic enzymes seem to be general mechanisms of attack both for plant pathogens and mycoparasitic antagonists. This knowledge is being used to identify receptors and key components of signalling pathways involved in fungus-fungus interaction. For this purpose we have cloned the first genes (tmk1, tga1, tga3) from T. atroviride showing a high similarity to MAP kinase and G protein subunits (see abstract by Zeilinger et al.), which have been found to have an important role in pathogenicity by Magnaporthe grisea. To identify the function and involvement of these factors in mycoparasitism by T. atroviride, tmk1, tga1, tga3 disruptant strains were produced. The knock-out mutants were tested by in vivo biocontrol assays for their ability to inhibit soil and foliar plant pathogens such as Rhizoctonia solani, Pythium ultimum and Botrytis cinerea . Disruption of these genes corresponded to a complete loss of biocontrol ability, suggesting a significant role in mycoparasitism. In particular, it has been suggested that tga3 regulates the expression of chitinase-encoding genes, the secretion of the corresponding enzymes and the process of conidiation. Comparative proteome analysis of wild type and disruptants supported this hypothesis, and indicated many changes in the protein profiles of T. atroviride in different interaction conditions with plants and pathogenic hosts.
基金Key projects of the Natural Science Foundation of Jiangxi Provincial Department of Education(GJJ190168)Advantages of Technological Innovation Teambuilding Program of Nanchang City,Innovation and Entrepreneurship Training Program of Jiangxi Agricultural University in 2020(No.147)。
文摘[Objectives]Lotus(Nelumbo nucifera Gaertn)is an economically important aquatic plant in China.Fungal disease is a serious problem in lotus cultivation.In this study,the pathogenic fungi on lotus in Nanchang City were investigated to lay the foundation for the disease control.[Methods]Lotus leaves and stems in ponds of Nanchang City were collected,the fungi on leave/stem spots were isolated and purified.Colonies morphological characters and ITS sequences were used to identify the strains.[Results]49 strains were isolated and identified to 20 species,belonging to 12 genera.[Discussion]15 species may firstly be reported on lotus in this study,i.e.,Alternaria angustiovoidea,Alternaria compacta,Alternaria ricini,Alternaria tenuissima,Arthrinium arundinis,Botryosphaeria dothidea,Curvularia spicifera,Diaporthe australiana,Diaporthe eres,Diaporthe tectonae,Epicoccum nigrum,Fusarium fujikuroi,Neofusicoccum parvum,Nigrospora sphaerica,and Phomopsis eucommii.
文摘Several features of adenoviruses make them anattractive option as a vehicle to transfer genes intoprimary malignant neoplasms in vivo. These viruseshave low pathogenicity in humans and are notneurotoxic. In addition, high titers of the virus can beachieved to allow higher levels of gene transfectionefficiency than the other vector systems. In vivotumorigenicity of G422 glioblastoma cells transfectedwith IL-2 and/or IL-3 genes decreased significantly inour privious report. In this study, recombinantadenoviruses were used to evaluate the therapeuticpotential of combined IL-2/IL-3 gene therapy in thetreatment of established subcutaneous tumor model ofG422 glioblastoma. Murine IL-2, IL-3 recombinantadenoviruses (2×10~8 pfu) were injected directly
基金supported by the National High Technology Research and Development Program of China(Project No. 2006AA02Z458)the Doctor Startup Foundation of Henan University of Science and Technology(09001350)
文摘In order to determine the effect of foreign genes on a transgenic parasite,the pathogenicity and development in chickens of transgenic E.tenella strain TE1,which expresses yellow fluorescent protein (YFP) and dihydrofolate reductase thymidylate synthase derived from Toxoplasma gondii(TgDHFR-TS), were compared with that of the parental strain BJ.Results indicated that the fecundity of the transgenic parasite(TE1) was reduced at least 4 times relative to that of the BJ strain.Low dosage of the TE1 strain induced less pathogenesis in chickens than did the BJ strain,but chickens inoculated with a higher dosage of TE1 oocysts displayed severe pathogenicity and mortality as did the BJ strain.In addition,trophozoites, the first generation and the second generation meronts and merozoites,microgamonts and macrogamonts of the transgenic parasite TE1 were seen by fluorescence microscopy.More interestingly,not all four sporonts in the sporulating transgenic oocysts express YFP.These findings suggest that the expression of YFP and TgDHFR-TS genes to some extent reduced pathogenicity and reproductive potential of transgenic E.tenella.Recombination between homologous or non-homologous chromosomes occurred during zygotic meiosis in E.tenella strain TE1.
文摘In plants,several cellular processes like celldivision,differentiation,polar growth,andresponse to pathogen attack depend on rapidreorganization of the actin cytoskeleton.Thereconstruction of actin filaments is controlled bya wide variety of actin-binding proteins,ofwhich,profilin is one of the key modulators.
基金supported by the Key Project of National Natural Science Foundation of China(30530550)
文摘The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into low-copy plasmid pWSK29 to construct the full-length cDNA clone pWSKBJC3/ w.The pWSKBJC3/w was in vitro transcribed and transfected into BHK-21 cells to rescue the virus.The results showed that the full-length cDNA clone was infectious and the virus could be rescued in BHK-21 cells.The rescued virus designated RvBJC3W was identified by RT-PCR and indirect immunofluorescence assay(IFA).The rescued virus had similar growth characteristics to its parental virus BJC3 and retained pathogenicity for mice.Our results indicate that the first infectious cDNA clone of EMCV in China has been successfully established and provides an essential tool for investigating the molecular basis of pathogenicity of EMCV.
基金Supported by the Science&Technology Department of Sichuan Province(2013FZ0014)the Construction Project of the Postgraduate Academic Degree in Southwest University for Nationalities(2013XWD-S071007)
文摘Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16S rDNA sequence analysis. Five virulence factors were detected, then artificial infection experiment and histopathological method were carried out. These results showed that strain YER6022 was one of Y. enterocolitica family members. In addition, ail, ystb, virF, yadA and HPIint were dectected. In artificial infection experiment, with 80% mortality and 100% morbidity, injected Pelteobagrus vachellis showed red swollen of the anus, abdomen swelling and fim bleeding. There existed serious hyperaemia and edema in kidney, spleen, intestine and liver at the light microscope. Ultrastructural observation indicated that mitochondria of the liver, kidney, spleen and intestine swelled and mitochondrial cristae broke. The data had further shed light on its pathogenicity in Pelteobagrus vachelli. It would benefit for further studies on pathogenesis ofPelteobagrus vachelli infected with Y. enterocolitica.
