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

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

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

OBJECTIVETo establish a rapid, sensitive and efficient detection method for tobacco mosaic virus (TMV), and provide technical support of TMV detection of Rehmannia glutinosa f. hueichingensis. The virus-free plantlets could be produced on a large scale to ameliorate breed degeneration caused by viral disease.

METHODSpecific primers were designed based on the conserved region of coat protein(CP) gene of TMV. Immunocapture RT-PCR (IC-RT-PCR) was employed to detect TMV and the sequence of the products was detected.

RESULTThe expected nucleotide acid fragments were amplified by IC-RT-PCR. The homology of nucleotide acid sequence and amino acid sequence were 95.29% and 96.7% between the PCR products and the CP gene of TMV (accession number AY555269).

CONCLUSIONThe method was established for the detection of TMV in R. glutinosa f. hueichingensis by IC-RT-PCR. This detection combined molecular biology technology with immunology, was convenient for a quick, sensitive and simple detection of TMV.

Amino Acid Sequence ; Base Sequence ; Molecular Sequence Data ; Rehmannia ; virology ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Tobacco Mosaic Virus ; genetics ; immunology ; isolation & purification

The AtTOM1 gene of Arabidopsis thaliana had been shown to be essential for the efficient multiplication of Tobacco mosaic virus (TMV) in A. thaliana. In this study, we cloned an AtTOM1-like gene from Nicotiana benthamiana named as NbTOM1. Sequence alignment showed that NbTOM1 is closely related to AtTOM1 homologues of N. tabacum and Lycopersicon esculentum with 97.2% and 92.6% nucleotide sequence identities, respectively. Silencing of NbTOM1 by a modified viral satellite DNA-based vector resulted in complete inhibition of the multiplication of TMV in N. benthamiana. The result suggests that inhibition of NbTOM1 via RNA silencing is a potentially useful method for generating TMV-resistant plants.
Arabidopsis Proteins ; genetics ; Cloning, Molecular ; Membrane Proteins ; genetics ; Plant Proteins ; antagonists & inhibitors ; genetics ; RNA Interference ; RNA, Plant ; RNA, Viral ; Sequence Homology ; Tobacco ; metabolism ; virology ; Tobacco Mosaic Virus ; physiology ; Virus Replication

In a previous study, we cloned popW from Ralstonia solanacearum strain ZJ3721, coding PopW, a new harpin protein. The procaryotically expressed PopW can induce resistance to Tobacco mosaic virus (TMV), enhance growth and improve quality of tobacco, when sprayed onto tobacco leaves. Here, we constructed an expression vector pB- popW by cloning popW into the bionary vector pBI121 and transformed it into Agrobacterium tumefaciens strain EHA105 via freeze-thaw method. Tobacco (Nicotiana tobacum cv. Xanthi nc.) transformation was conducted by infection of tobacco leaf discs with recombinant A. tumefaciens. After screening on MS medium containing kanamycin, PCR and RT-PCR analysis, 21 T3 lines were identified as positive transgenic. Genomic intergration and expression of the transferred gene were determined by PCR and RT-PCR. And GUS staining analysis indicated that the protein expressed in transgenic tobacco was bioactive and exhibited different expression levels among lines. Disease bioassays showed that the transgenic tobacco had enhanced resistance to TMV with biocontrol efficiency up to 54.25%. Transgenic tobacco also exhibited enhanced plant growth, the root length of 15 d old seedlings was 1.7 times longer than that of wild type tobacco. 60 d after transplanting to pots, the height, fresh weight and dry weight of transgenic tobacco were 1.4, 1.7, 1.8 times larger than that of wild type tobacco, respectively.
Agrobacterium tumefaciens ; Animals ; Bacterial Outer Membrane Proteins ; genetics ; Disease Resistance ; genetics ; Genetic Vectors ; Phenotype ; Plant Diseases ; prevention & control ; virology ; Plants, Genetically Modified ; genetics ; Tobacco ; genetics ; Tobacco Mosaic Virus ; Transformation, Genetic

A new naphthaldehyde derivative has been isolated from Comastoma pulmonarium by using various chromatographic techniques, including silica gel, Sephadex LH-20, MCI-gel resin and RP-HPLC. This compounds was determined as 5-methoxy-2-methyl-7-(2-oxopropyl)naphthalene-1-carbaldehyde(1) by NMR, MS, IR and UV spectra. This compound was also evaluated for its anti-tobacco mosaic virus (anti-TMV) activity. The result showed that it showed high anti-TMV activity with inhibition rate of 32.8%. The inhibition rate is close to that of positive control (ningnanmycin).
Aldehydes ; isolation & purification ; pharmacology ; Antiviral Agents ; isolation & purification ; pharmacology ; Chromatography, High Pressure Liquid ; Gentianaceae ; chemistry ; Naphthalenes ; isolation & purification ; pharmacology ; Phytochemicals ; isolation & purification ; pharmacology ; Tobacco ; Tobacco Mosaic Virus ; drug effects

A phytochemical investigation on the stems of Garcinia bracteata collected from Xishuangbanna resulted in the isolation of a new flavone. By analysis of the HRESIMS, IR, UV, 1D and 2D NMR spectra, the structure of the new compound was determined as 7-methoxy-4',6-dihydroxy-8-isobutyryl-flavone(1). Compound 1 was also tested for its anti-tobacco mosaic virus(TMV) activity. Results suggested the 1 possessed remarkable anti-TMV activity, with an inhibition rate of 28.2%.
Antiviral Agents ; chemistry ; isolation & purification ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; Flavones ; chemistry ; isolation & purification ; pharmacology ; Garcinia ; chemistry ; Magnetic Resonance Spectroscopy ; Plant Leaves ; chemistry ; Tobacco Mosaic Virus ; drug effects ; growth & development