ABSTRACT
BACKGROUND: Rice sheath blight (caused by Rhizoctonia solani) and tobacco mosaic virus are very important plant diseases, causing a huge loss in global crop production. Paenibacillus kribbensis PS04 is a broad-spectrum biocontrol agent, used for controlling these diseases. Previously, extracellular polysaccharides (EPS) from P. kribbensis PS04 had been purified and their structure was inferred to be fructosan. This study aimed to evaluate the effects of exogenous EPS treatment on plantpathogen interactions. RESULTS: Plant defense genes such as phenylalanine ammonia-lyase, catalase, chitinase, allene oxide synthase, and PR1a proteins were significantly induced by exogenous EPS treatment. Moreover, subsequent challenge of EPSpretreated plants with the pathogens (R. solani or tobacco mosaic virus) resulted in higher expression of defenseassociated genes. Increased activities of defense-associated enzymes, total phenols, and flavonoids were also observed in EPS pretreated plants. The contents of malondialdehyde in plants, which act as indicator of lipid peroxidation, were reduced by EPS treatment. CONCLUSIONS: This study comprehensively showed that EPS produced from P. kribbensis PS04 enhances disease resistance in plants by the activation of defense-associated genes as well as through the enhancement of activities of defense-related enzymes.
Subject(s)
Plant Diseases/immunology , Rhizoctonia/pathogenicity , Tobacco Mosaic Virus/pathogenicity , Paenibacillus/immunology , Plant Diseases/microbiology , Polysaccharides, Bacterial , Pest Control, Biological , Host-Pathogen Interactions , Paenibacillus/genetics , Disease Resistance/genetics , Real-Time Polymerase Chain Reaction , Fructose/analogs & derivativesABSTRACT
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.
Subject(s)
Alkaloids , Antiviral Agents , Isoquinolines , Thalictrum , Tobacco Mosaic VirusABSTRACT
OBJECTIVE@#To assess the potential of transient expression of recombinant human plasminogen activator (rhPA) in plants as a cost-effective approach for recombinant rhPA production.@*METHODS@#Tobacco mosaic virus-based expression vector pTMV rhPA-NSK and plant binary expression vector pJ Zera-rhPA were constructed by sequence synthesis and subcloning. The two vectors were inoculated on either or leaves agroinfiltration. The expression of recombinant rhPA in leaves was examined using Western blotting and ELISA, and the fibrinolysis activity of plant-produced rhPA was assessed by fibrin agarose plate assay (FAPA).@*RESULTS@#Five to nine days after infiltration with an inoculum containing pTMV rhPA-NSK, necrosis appeared in the infiltrated area on the leaves of both plants, but intact recombinant rhPA was still present in the necrotic leaf tissues. The accumulation level of recombinant rhPA in infiltrated leaves was significantly higher than that in leaves ( < 0.05). The yield of recombinant rhPA was up to 0.6% of the total soluble protein (or about 60.0 μg per gram) in the fresh leaf biomass at 7 days post-inoculation. The plant-derived rhPA was bioactive to convert inactive plasminogen to active plasmin. No necrosis occurred in pJ Zera-rhPA-infiltrated leaves. The Zera-rhPA protein was partially cleaved between the site of Zera tag and rhPA sequence in both leaves. We speculated that the formation of Zera tags-induced particles in the plant cells was a dynamic process of progressive aggregation in which some of the soluble polypeptides were encapsulated in these particles.@*CONCLUSIONS@#Enzymatically active recombinant rhPA can be rapidly expressed in tobacco plants using the plant viral ampliconbased system, which offers a promising alternative for cost-effective production of recombinant rhPA.
Subject(s)
Humans , Plant Leaves , Plants, Genetically Modified , Plasminogen , Plasminogen Activators , Metabolism , Recombinant Proteins , TobaccoABSTRACT
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).
Subject(s)
Aldehydes , Pharmacology , Antiviral Agents , Pharmacology , Chromatography, High Pressure Liquid , Gentianaceae , Chemistry , Naphthalenes , Pharmacology , Phytochemicals , Pharmacology , Tobacco , Tobacco Mosaic VirusABSTRACT
Objective:In order to establish ELISA method for testing tobacco mosaic virus (TMV) infecting Zingiber officinale Rosc.Methods: Tobacco mosaic virus(TMV) infecting Zingiber officinale Rosc was tested by RT-PCR.Zingiber officinale Rosc leaves which only contained TMV were choiced.TMV particle was purified by centrifugation method.TMV CP was purified through preparation electrophoresis including 12％ SDS-PAGE first and then 5％-20％ gradient SDS-PAGE.Polyacrylamide gel contained TMV CP was ground into suspension.Mice were immuned with the suspension and antiserum was obtained.Antiserum quality was tested by Western blot and ELISA test.IgG was purified through affinity chromatography method.IgG solution was concentrated and dialyzed to a suitable concentration.The IgG then mixed with glycerol.Results: IgG in antiserum only combined with TMV CP protein and it could combine with nature TMV particle CP protein.Its quality was up to standard.Conclusion: Establishment of ELISA method for testing TMV infecting Zingiber offcinale Rosc is successfull by using this IgG.
ABSTRACT
Munronia Wight has been widely used in folk of China. Due to the rich content of limonoid, this genus has always been a hot research topic. So, many researches on phytochemistry and pharmacology of this genus have been carried out over the past 20 years. In this paper, the systematic classification, chemical constituents, and pharmacological effects of plants from Munronia Wight have been summarized. It may provide the reference for the further studies of this genus.
ABSTRACT
Tobacco mosaic virus (TMV) causes significant yield loss in susceptible crops irrigated with contaminated water. However, detection of TMV in water is difficult owing to extremely low concentrations of the virus. Here, we developed a simple method for the detection and quantiifcation of TMV in irrigation water. TMV was reliably detected at concentrations as low as 10 viral copies/μL with real-time PCR. The sensitivity of detection was further improved using polyethylene glycol 6000 (PEG6000, MW 6000) to concentrate TMV from water samples. Among the 28 samples from Shaanxi Province examined with our method, 17 were tested positive after virus concentration. Infectivity of TMV in the original water sample as well as after concentration was conifrmed using PCR. The limiting concentration of TMV in water to re-infect plants was determined as 102 viral copies/mL. The method developed in this study offers a novel approach to detect TMV in irrigation water, and may provide an effective tool to control crop infection.
ABSTRACT
Objective: To study the chemical constituents from Swertia macrosperma. Methods: HPLC, column chromatography, and recrystallization techniques were used for the separation and purification of the compounds. Their structures were elucidated by physiochemical properties and spectral analyses. The inhibitory activity against tobacco mosaic virus (TMV) was screened by half-leaf blight spot assay. Results: Eight compounds were isolated from S. macrosperma and their structures were identified as 9, 10-dihydroxyl-sweroside (1), 3'-O-(3-hydroxybenzoyl)-swertiamarin (2), mangiferin (3), 1-O-β-glucopyranosyl-2, 6, 8-trihydroxyl-xanthone (4), campestroside (5), bellidifolin (6), 4, 4'-dihydroxy-Z-stilbene (7), and 4, 4'-dihydroxy-E-stilbene (8). Conclusion: Compound 1 is a new compound named macrospermaoside A, and exhibits weak anti-TMV activity. Compounds 2, 7, and 8 are isolated from the plants of this genus for the first time.