OBJECTIVETo study viruses infecting Pinellia ternata in China.

METHODSymptom observation, DAS-ELISA and RT-PCR detection were applied.

RESULT AND CONCLUSIONDuring a survey in early spring, SMV and CMV were both commonly distributed as main viruses infecting P. ternata collected from different areas in China. But DsMV was the virus which infected P. ternate in natural condition. The infection ratio of cultivated P. ternate by SMV and CMV were 71.4% and 14.3% respectively for 21 samples collected from Ningbo, Zhejiang province; 100% and 44.4% for 18 samples from Xiaoshan, Zhejiang province; 61.9% and 33.3% for 21 samples from Hebei province; 50.0% and 41.7% for 12 samples from Anhui province; 16.7% and 16.7% for 12 samples from Sichuan province; 31.3% and none for 16 samples from Beijing. And the infection ratio of 25 wild samples from different areas of China infected by SMV and CMV were both 20.0%.

China ; Cluster Analysis ; Cucumovirus ; genetics ; isolation & purification ; DNA, Complementary ; chemistry ; genetics ; Mosaic Viruses ; classification ; genetics ; isolation & purification ; Pinellia ; virology ; Plant Diseases ; virology ; Plants, Medicinal ; virology ; Sequence Analysis, DNA

To unveil genetic variations between the predominant soybean mosaic virus (SMV) strains in China and in the USA, as well as to reveal the potential relevance between the similarity of gene sequences and the virulence of the viruses, we isolated and sequenced the coat protein (CP) gene of Chinese SMV strain SC7 by RT-PCR and compared the SC7 sequence with those of SMV strains from the USA. Analysis is showed that the CP gene of SC7 was 795 nucleotides in length and encoded 265 in amino acids'. The CP gene of SC7 and those of the strains from the USA exhibited 4%-5% nucleotide diversity and 1%-2% diversity amino acids. The conserved amino-acid sequence associated with aphid spread in the USA strains was DAG, and corresponded to DAD in SC7. The virulence of SC7 was greater than that of the SMV strains from the USA. Nevertheless, no clear relationships between sequence similarity of the CP genes from different strains and their virulence on differential hosts were found.
Amino Acid Sequence ; Capsid Proteins ; genetics ; China ; Molecular Sequence Data ; Mosaic Viruses ; Soybeans ; virology ; United States

The MDMV (Maize Dwarf Mosaic Virus, MDMV) CP (Coat Protein, CP) gene was cloned by RT-PCR method and introduced into the embryonic calli derived from immature embryos of elite inbred 18-599hong and 18-599bai via particle bombardment. Bombarded calli were selected on selection medium containing 5-10 mg/L (PPT) Bialaphos. From resistant calli, 79 plantlets were regenerated. 18 of 79 were grown and harvested. The results of Southern blotting and PCR analysis demonstrated that MDMV CP have been integrated into the genome of the transgenic plants. PCR-positive progeny plants were artificially inoculated with MDMV strain B, and the average chlorosis of the functional leaves of each plant was investigated. The typical symptoms were observed from the leaves of the control inbreds. while, the presence of the MDMV CP gene provided resistance to inoculation with MDMV strain B.
Capsid Proteins ; genetics ; Cloning, Molecular ; Mosaic Viruses ; genetics ; Plant Diseases ; genetics ; virology ; Plants, Genetically Modified ; Transfection ; Zea mays ; genetics ; virology

HC-pro gene of Watermelon Mosaic virus was obtained by RT-PCR was 1371bp in length. It was cloned into pPI(9K, then the eucaryotic recombinant expression plasmid pPIC9K-WHC was constructed. After being linearized with restriction endonuclease Sal I , the recombinant plasmid was transformed into Pichia pastoris GS115 by electroporation. The high copy transformants with Mut+ /His+ phenotype were selected by RT-PCR and screening on G418, MD and MM medium. Induced by methanol for 5 days, the culture supernatant was analyzed by SDS-PAGE, the results showed that a specific protein with a molecular weight of about 66 kD was expressed. Western blot analysis proved that the expression protein could specifically bind to HC-Pro polyclonal antibody. Far western blot analysis proved that the expression protein could bind to coat protein, given support to "bridge" hypothesis that HC-Pro help aphid transmission of non-persistent viruses.
Citrullus ; virology ; Cysteine Endopeptidases ; biosynthesis ; genetics ; Mosaic Viruses ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Viral Proteins ; biosynthesis ; genetics

SMV is one of main diseases of soybean, which could affect yields and quality of soybean seriously. It was effective to soybean breeding by studying the expression of resistant gene to SMV with molecular technology. In this study, a soybean resistance line, DongNong 8143, was used to construct a subtractive cDNA library by SSH from soybean leaves inoculated by SMV No.1 at primary stage. cDNA dominantly or specifically expressed in infected leaves was purified using PCR Purification Kit and cloned into pGEM-T easy vector. Colonies were grown on LB-agar plates containing ampicillin, X-gal and IPTG. A subtractive plasmid library was constructed by SSH. Then the library was transformed to host bacteria E. coli DH5alpha, and the titer of the library was measured as 2 x 10(3) . 64 clones were picked up randomly and sequenced. Of them there is 50 clones which result of sequenced were good. The length of EST fragment varied from 136bp to 691bp, and the average length is 456bp. Among them, 41 sequences has poly(A). Through ESTs were compared with sequences in unigene database of GeneBank with BLASTn and BLASTx algorithm, 38 ESTs of them had comparatively clear results and the percent of them in acquired ESTs is 74%. The EST expression profile showed that the resistance-related genes include cell protection, signal transduction, restrict pathogen growth, system acquired resistance, and house-keeping gene. There are 12 ESTs, which have not comparatively clear results, that maybe new genes.
Expressed Sequence Tags ; Gene Library ; Mosaic Viruses ; Nucleic Acid Hybridization ; methods ; Plant Diseases ; genetics ; virology ; Polymerase Chain Reaction ; Soybeans ; genetics ; virology

A new isoquinoline alkaloid(1) has been isolated from the whole plant of Thalictrum glandulosissimum by using various chromatographic techniques, including silica gel, sephadex, MCI-gel resin, and RP-HPLC, and its structure was determined as 1-(6-hydroxy-7-methylisoquinolin-1-yl) ethantone by physicochemical properties and spectroscopic data. This compound was evaluated for anti-tobacco mosaic virus(TMV) activity. The results showed that it had prominent anti-TMV activity with inhibition rates of 28.4%. This rate was closed to that of positive control.
Alkaloids ; Antiviral Agents ; Isoquinolines ; Thalictrum ; Tobacco Mosaic Virus

Aims: The cucumber mosaic virus (CMV) is categorized under the genus Cucumovirus and family Bromoviridae. This virus is known to infect over 1200 plant species from 100 families, including ornamental and horticultural plants. In this study, we pioneered a global genome comparison to decipher the unknown orchestrators behind the virulence and pathogenicity of CMV via the discovery of important single nucleotide polymorphic markers. Methodology and results: As a result, the genome size was found to be a potential preliminary country-specific marker for South Korea and the GC content can be utilized to preliminarily differentiate Turkey isolates from the others. The motif analysis as well as whole genome and coat protein phylogenetic trees were unable to form country-specific clusters. However, the coat protein haplotype analysis had successfully unconcealed country-specific single nucleotide polymorphic markers for Iran, Turkey and Japan isolates. Moreover, coat protein modelling and gene ontology prediction depicted high conservation across CMV isolates from different countries. Conclusion, significance and impact of study The country-specific single nucleotide polymorphic markers unearthed in this study may provide significant data towards the profiling of varying virulence and pathogenicity of CMV across the globe in time to combat the yield loss driven by this virus thru the most efficacious biological control measures in the future.
Cucumovirus--genetics ; Genome, Microbial

To confirm the inactivating effect of chito-oligosaccharides on Tobacco mosaic virus (TMV) par ticles in vitro, the difference of TMV pathogenicity was evaluated according to the decrease of local lesion numbers after inoculating with TMV mixed with chito-oligosaccharides (DP3-10) in Nicotiana glutinosa, and the virion structural change was studied by transmission electron microscopy after mixed with chito-oligosaccharides. In the range of tested concentrations of chito-oligosaccharides (100-1000 microg /mL), the numbers of local lesions were strongly reduced with over 30% decrement, and the 88.4% reduction gained at the concentration of 600g /mL. It revealed that treatment with chito-oligosaccharide solution of 300-500 microg /mL directly broke TMV particles into tiny pieces of 50-150nm long, and that treatment with solutions of 600-1000 microg/mL caused virus particle agglomerated. The data presented here suggested that chito-oligosaccharides exerted strong inactivating effect on plant virus in vitro.
Microscopy, Electron, Scanning ; Oligosaccharides ; pharmacology ; Tobacco Mosaic Virus ; drug effects ; ultrastructure ; Virion ; drug effects ; ultrastructure

Detection of protein-protein interaction can provide valuable information for investigating the biological function of proteins. The current methods that applied in protein-protein interaction, such as co-immunoprecipitation and pull down etc., often cause plenty of working time due to the burdensome cloning and purification procedures. Here we established a system that characterization of protein-protein interaction was accomplished by co-expression and simply purification of target proteins from one expression cassette within E. coli system. We modified pET vector into co-expression vector pInvivo which encoded PPV NIa protease, two cleavage site F and two multiple cloning sites that flanking cleavage sites. The target proteins (for example: protein A and protein B) were inserted at multiple cloning sites and translated into polyprotein in the order of MBP tag-protein A-site F-PPV NIa protease-site F-protein B-His(6) tag. PPV NIa protease carried out intracellular cleavage along expression, then led to the separation of polyprotein components, therefore, the interaction between protein A-protein B can be detected through one-step purification and analysis. Negative control for protein B was brought into this system for monitoring interaction specificity. We successfully employed this system to prove two cases of reported protien-protein interaction: RHA2a/ANAC and FTA/FTB. In conclusion, a convenient and efficient system has been successfully developed for detecting protein-protein interaction.
Endopeptidases ; genetics ; metabolism ; Escherichia coli ; genetics ; Plum Pox Virus ; enzymology ; genetics ; Protein Interaction Mapping ; methods ; Proteolysis

Studies have shown that transgenic plants expressing antiapoptotic genes from baculovirus and animals increase resistance to biotic and abiotic stress. However, the mechanism under these resistances is conjectural, or in some cases even controversy. In the present study, the p35 gene from baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) was expressed in tobacco, and for the first time P35 protein was detected in transgenic plants by Western blotting. Inoculation of T1 transgenic tobacco leaves with tobacco mosaic virus (TMV) showed enhanced resistance, and DNA laddering was observed after TMV infection in control but not in transgenic plants. DAB staining showed that TMV infection did not affect peroxide induction of transgenic plants, Western blotting analysis of PR1 protein also showed no difference of control and transgenic plants. Inoculation of fungus (Sclerotinia sclerotiorum) using a detached leaf assay showed enhanced resistance of transgenic leave tissue. RT-PCR analysis demonstrated that p35 gene expression induced earlier expression of PR1 gene after S. sclerotiorum infection. Taken together, our results suggest that the mechanism under enhanced disease resistance by P35 protein is possibly related to the activation of PR-related proteins in addition to the inhibition of programmed cell death, depending on the pathogens challenged.
Gene Expression Regulation, Plant ; Immunity, Innate ; Plant Diseases ; genetics ; Plants, Genetically Modified ; genetics ; immunology ; virology ; Tobacco ; genetics ; immunology ; virology ; Tobacco Mosaic Virus ; Transformation, Genetic ; Viral Proteins ; genetics ; metabolism