| polyamino acid induced aphid transmission of plant viruses. | aphids transmitted poly-l-ornithine (plo)-treated tobacco mosaic virus (tmv) when given acquistion and inoculation access periods as brief as 30 s and 2 min, respectively; the ability to transmit was lost within 90 min. aphids without claws were able to transmit the virus. transmission thus seems similar to that of nonpersistent viruses. the ratio of virus to polyamino acid, as well as the kcl concentration, markedly affected transmission. transmission was best from mixtures which contained 250 ... | 1975 | 1467 |
| a ph-dependent conformational change in the coat protein subunits from potato virus x. | both the circular dichroism and fluorescence spectra of the dissociated coat protein subunits from potato virus x changed substantially over the ph range 8 to 4, irreversible changes resulted below ph 4, with tyrosyl and tryptophanyl residues affected most. the titration curves show a pka of about 5.6 and do not require cooperative interactions between the coat protein subunits, thus they are in marked contrast to titrations of tobacco mosaic virus a-protein. the spectra of the intact virus were ... | 1976 | 10980 |
| assembly of flexuous plant viruses and their proteins. | recent experiments on the disassembly and assembly of some flexuous plant viruses and their proteins are described. the properties of reconstituted potato virus x and those of assembled potato virus y protein are considered as well as the suitability of other flexuous viruses for reconstitution studies. | 1976 | 13429 |
| antiphytoviral activity of 2,4 dioxo hexahydro triazine. | three treatments with 2,4 dioxo hexahydro triazine (dht) significantly reduced the concentration of potato virus x (pvx) in systemically infected tobacco plants. in hypersensitive plants dht caused a reduction in the number of local lesions produced by pvx. in systemic and hypersensitive hosts, treatment with dht resulted in a more or less marked reduction in the concentration of, and in the number of local lesions caused by, potato virus y (pvy), potato virus a (pva), tobacco mosaic virus (tmv) ... | 1979 | 42301 |
| reconstruction of potato virus x in vitro. ii. characterization of the reconstituted product. | | 1975 | 53939 |
| [dioxohexahydrotriazine, a new synthetic antiphytoviral compound (author's transl)]. | this paper reports the first results of studies made to determine the antiviral activity of dioxo hexahydro triazine, a newly developed antiphytoviral compound. after treatment with dioxo hexahydro triazine, the concentration of helical potato virus x in leaves of nicotiana tabacum "samsun" was found to be considerably reduced in both the serological test and local lesion test conducted on nicotiana glutinosa at temperatures of 14 degrees c +/- 3 degrees c. in secondarily infected leaves, the re ... | 1979 | 473960 |
| analysis of terminal structures of rna from potato virus x. | the 5'-end structure of potato virus x rna was determined following enzymatic methylation in vitro. a single 3h-methyl group was introduced into the 2'-position of the 5'-penultimate residue and the end structure was determined as m7gpppg(m)pap(xp)3g. this part of the rna apparently is involved in binding to ribosomes since it can be partially protected against rnase digestion by wheat germ 40s ribosomes. pvx rna was not retained by poly(u)-sepharose, indicating that it does not contain a 3'-ter ... | 1978 | 673859 |
| [on the effect of some morpholinium compounds on the multiplication of rna viruses (author's transl)]. | in the present paper the authors report about the effect of n,n-dimethylmorpholinium chloride (dmmc), n,n-dimethyl-2-oxomorpholinium chloride (dmomc), and n,n-diethyl-2-oxomorpholinium chloride (deomc) on the multiplication of tobacco mosaic virus (tmv), potato virus x (pvx), and cucumber mosaic virus (cmv) as well as the plaque formation by the rna phages m 12, f 2, and qbeta. the used morpholinium compounds do not influence strikingly the multiplication of phytoviruses. the results found by se ... | 1978 | 685536 |
| [structurally dependent effects of substituted thioureas on the concentration of potato virus x in nicotiana tabacum l. "samsun" (author's transl)]. | a study has been made to investigate the effects of n-alkyl- and aryl-substituted thioureas as well as n,n'-alkyl-alkyl-, alkyl-aryl-, and aryl-aryl-substituted thioureas on the multiplication of pvx in nicotiana tabacum l. "samsun". the virus concentrations of the treated plants were serologically determined and compared with these of untreated controls. the weak antiphytoviral effect of nonsubstituted thiourea remained virtually unchanged in n,n'-dimethyl thiourea, and in n,n,n'-trimethyl thio ... | 1978 | 749413 |
| regeneration of plants from protoplasts of potato virus x-infected tobacco leaves. | | 1975 | 808032 |
| reconstitution of potato virus x in vitro. iii. evidence for a role for hydrophobic interactions. | | 1977 | 835246 |
| regeneration of plants from prtoplasts of potato virus x-infected tobacco leaves. ii. influence of virazole on the frequency of infection. | | 1977 | 860402 |
| [nature and function of the x-bodies in the potato virus x]. | | 1976 | 948272 |
| [action of gamma irradiation on the infectivity of the potato virus x, the tmv and their rnas]. | | 1976 | 967058 |
| [purification of pvy, pvx, tmv and spherical virus of pinks using polyethylene glycol and gel filtration]. | | 1976 | 1012092 |
| circular dichroism and fluorescence studies on potato virus x and its structural components. | circular dichroism (dc) measurements of the coat protein subunits of potato virus x show that native subunits that can reassemble with rna to form infectious virus particles have appreciable alpha-helical structure. the cd of intact potato virus x was less intense below and more intense above 250 nm, and the maxima and minima were at longer wavelengths, than those of a cd spectrum computed from the individual contributions of the coat protein and rna. the differences between the measured and com ... | 1975 | 1125233 |
| purification of filamentous plant viruses by thin layer centrifugation. | the construction of a modified thin layer ultracentrifuge rotor is described. this rotor was used in the purification of five filamentous plant viruses, viz. tmv, scmv, pvx, sgv and ymc. the purification and concentration of these viruses in their monomeric forms is hazardous when conventional "tube" rotors are used since they invariably result in dissociation and aggregation of the virus particles. using the thin layer rotor these infective agents may be concentrated in volumes of fluid equal t ... | 1975 | 1178651 |
| structure of products of protein reassembly and reconstruction of potato virus x. | | 1975 | 1179645 |
| reconstitution of potato virus x in vitro. i. properties of the dissociated protein structural subunits. | | 1975 | 1198920 |
| [effect of the method of tissue culture and the way of its inoculation as applied to the accumulation of potato virus x and tobacco mosaic virus]. | | 1975 | 1207517 |
| [electron microscopic study of double infection induced by potato virus x and potato virus y in nicotiana glutinosa]. | | 1975 | 1214639 |
| [purification of potato virus x]. | | 1975 | 1214646 |
| [obtaining of plants-regenerants from tobacco clone tissue and determination of their sensitivity to potato virus x]. | | 1975 | 1214654 |
| [effect of temperature on the reaction of datura stramomium l. plants infected with potato virus x]. | | 1975 | 1214661 |
| [immunochemical analysis of the synthetic peptides incorporated into the protein antigenic determinant of the potato virus x coat]. | three peptides located in the n-terminal region of the potato virus x coat protein were synthesized by hand solid phase method for epitope mapping of this protein. one of these peptides (nanopeptide) interacted with monoclonal antibodies to native virus x. on the basis of these studies it was assumed, that amino acid sequence of the potato virus x coat protein, which included lysine residue in position 19, is located on the virion surface. | 1992 | 1280379 |
| the 5'-untranslated leader sequence of potato virus x rna enhances the expression of a heterologous gene in vivo. | the 5' untranslated leader of potato virus x (pvx) rna is shown when contiguous to the coding sequence, to enhance the expression of the neomycin phosphotransferase ii gene (nptii) in nicotiana tabacum protoplasts in vivo. the level of transient expression of the nptii gene in protoplasts provided by a plasmid containing the coding sequence of the nptii gene under the control of 35s cauliflower mosaic virus (camv) promoter and terminator elements served as the baseline control. insertion of the ... | 1992 | 1324400 |
| the nucleotide sequence and genome organization of strawberry mild yellow edge-associated potexvirus. | the nucleotide sequence (5966 nucleotides) of cdna clones of strawberry mild yellow edge-associated potexvirus was determined. the genome contains six open reading frames (orfs) encoding putative proteins with mrs of 149,423, 25,344, 11,576, 8079, 25,714 and 11,216. in the first three putative proteins and the coat protein considerable similarity was found to comparable polypeptides of the potexviruses potato virus x, clover yellow mosaic virus, narcissus mosaic virus, papaya mosaic virus, white ... | 1992 | 1339469 |
| establishment of hybridoma cell line secreting specific monoclonal antibodies against turnip mosaic virus and analysis of properties of the mcab. | monoclonal antibodies (mcab) of hybridomas derived from the fusing of the mouse splenocytes immunized by tumv with balb/c mouse myeloma cells (sp2/0-ag14). five kinds of hybridoma cell line were produced by indirect-elisa screening and cloning three times with limiting dilution. four kinds of hybridoma produced antibodies respectively reactive to tumv c1, c3, c4 and c5. one kind was reactive to all five strains of tumv. in indirect-elisa and sandwich-elisa tests, tumv specific monoclonal antibod ... | 1992 | 1343828 |
| potato virus x as a vector for gene expression in plants. | the suitability of potato virus x (pvx) as a gene vector in plants was tested by analysis of two viral constructs. in the first, the gus gene of escherichia coli was substituted for the viral coat protein gene. in the second, gus was added into the viral genome coupled to a duplicated copy of the viral promoter for the coat protein mrna. the viral construct with the substituted coat protein gene accumulated poorly in inoculated protoplasts and failed to spread from the site of infection in plant ... | 1992 | 1344890 |
| the r1 gene conferring race-specific resistance to phytophthora infestans in potato is located on potato chromosome v. | late blight in potato is caused by the fungus phytophthora infestans and can inflict severe damage on the potato crop. resistance to p. infestans is either based on major dominant r genes conferring vertical, race-specific resistance or on "minor" genes inducing horizontal, unspecific resistance. a dihaploid potato line was identified which carried the r1 gene, conferring vertical resistance to all p. infestans races, with the exception of those homozygous for the recessive virulence allele of t ... | 1992 | 1351246 |
| factors influencing immune electron microscopy of flexuous potato viruses. | effects of ph of extraction buffers, ph and titer of trapping antisera and their combinations, virus acquisition time and virus host on the trapping efficiency of flexuous potato viruses x, s and y (pvx, pvs and pvy) in immune electron microscopy were evaluated. addition of ethylene-diamine-tetraacetic acid to the extraction buffer improved trapping of pvy, adversely affected pvs but not pvx. combinations of antisera had differential adverse effect on trapping which was maximum with the mixture ... | 1992 | 1364019 |
| the effect of an egyptian isolate of streptomyces afghanensis on some plant viruses. | an egyptian isolate of streptomyces afghanensis was examined for the production of antiviral metabolites. concentrated broth exudates of this microorganism were tested against tobacco mosaic virus (tmv), tomato mosaic virus (tomv) and potato virus x (pvx) infecting nicotiana tabacum l. cv. white burley. both concentrated metabolites and their acetone extract inhibited local lesion development of the tested viruses. in all cases, maximum antiviral effect was observed 2 hr after infection. the ult ... | 1992 | 1364025 |
| engineering resistance to mixed virus infection in a commercial potato cultivar: resistance to potato virus x and potato virus y in transgenic russet burbank. | potato virus x (pvx) and potato virus y (pvy) infection in potato may result in the loss of certification of seed potatoes and affect quality and yield of potatoes in commercial production. we transformed a major commercial cultivar of potato, russet burbank, with the coat protein genes of pvx and pvy. transgenic plants that expressed both cp genes were resistant to infection by pvx and pvy by mechanical inoculation. one line was also resistant when pvy was inoculated with viruliferous green pea ... | 1990 | 1366358 |
| increased resistance to potato virus x and preservation of cultivar properties in transgenic potato under field conditions. | during the last three years we performed field trials to assess levels of resistance against potato virus x (pvx) and changes in intrinsic properties of the potato cultivars bintje and escort upon the introduction of the pvx coat protein (cp) gene. analysis of leaf and tuber samples collected in the field at two week intervals revealed a stable expression of the pvx cp gene throughout the growing season. this resulted in a large decrease in pvx incidence among clonal progeny obtained from previo ... | 1992 | 1368486 |
| the topography of the surface of potato virus x: tritium planigraphy and immunological analysis. | thermally activated tritium atoms were used to probe the surface topography of the coat protein of potato virus x (pvx) potexvirus. the accessibility profile of amino acid residues in the polypeptide chain was determined from data on the intramolecular distribution of tritium label in the pvx coat protein. tryptic peptides t1 and t2, as well as parts of peptides t3 and t5, from the pvx particles were all located in the n-terminal region of the pvx coat protein and were accessible to tritium labe ... | 1992 | 1371539 |
| exogenous primer-independent cdna synthesis with commercial reverse transcriptase preparations on plant virus rna templates. | upon reverse transcription and cloning manipulations with virion rnas of several plant viruses, namely beet yellows virus, brome mosaic virus, and potato virus x, we came across a significant background synthesis of cdna on the virion rna template in vitro independent of exogenous primers added. when tested with beet yellow virus rna template, several commercial preparations of avian myeloblastosis virus (amv) reverse transcriptase showed the background activity monitored by the [alpha-32p]dntp ... | 1992 | 1381874 |
| [determination of the effectiveness of rna cross-linking with protein induced by uv-radiation in potato x-virus particles]. | the uv-irradiation was found to induce formation of the rna-protein cross-links and intraviral rna chain breaks in the particles of flexuous potato virus x (pvx). using the technique developed previously for the rod-like tobacco mosaic virus (tmv), the quantum yields of rna-protein cross-links and intraviral rna polynucleotide chain breaks formation in the pvx were determined and found to be more or less close to those found for the intraviral tmv rna. | 1992 | 1406761 |
| mutational analysis of the coat protein gene of potato virus x: effects on virion morphology and viral pathogenicity. | the role of the coat protein of potato virus x (pvx) was investigated by site-directed mutation of the coat protein gene. mutant viruses with in-frame deletions in the 5' end of the coat protein gene were capable of systemically infecting plants, but produced virions with atypical morphology. viruses with a frameshift mutation near the 5' end or with deletions in the central part of the coat protein gene failed to accumulate at detectable levels, even in the inoculated leaf. in protoplasts, muta ... | 1992 | 1413503 |
| production of monoclonal antibody in hollow fiber culture system with serum-free medium. | hybridoma cells 7e8, secreting mouse monoclonal antibody (mcab) igg against potato virus x, were cultured in hollow fiber cell culture system (module vf-2) with serum-free medium 1640sfm. the maximum viable cell density was found to be 2.34 x 10(6) cells/ml that was 3.7 and 2.2 times as high as those achieved in spinner and static flask culture respectively. about 10,000ml of cell culture media had been collected in the cultural period of 42 days. the elisa titer of the mcab in the media was abo ... | 1992 | 1457721 |
| resistance to phloem transport of potato leafroll virus in potato plants. | a 'double-graft sandwich' technique in which sections of potato stem from different potato cultivars were grafted between a susceptible healthy stock plant and a potato leafroll virus (plrv)-infected scion was used to study the rate of phloem transport of plrv in cultivars differing in resistance to plrv infection (ir) and accumulation (ar). resistance to phloem transport (i.e. delayed plrv systemic movement) was found in bismark cultivar (ir a(s)). this was independent of ir and ar as the rate ... | 1992 | 1469360 |
| examination of potato virus x proteins synthesized in infected tobacco plants. | nucleotide sequence analysis of potato virus x (pvx) genomic rna predicts five open reading frames (orfs). previous analysis of total rnas from pvx-infected leaf tissue suggested that six subgenomic rnas are synthesized during infection. however, the proteins encoded by the genomic rna, the subgenomic rnas, or the predicted orfs have not been identified in vivo. to characterize the coding properties of the viral rna, particularly to determine whether the five predicted orfs function in vivo, tot ... | 1992 | 1501297 |
| translation enhancing properties of the 5'-leader of potato virus x genomic rna. | the double-stranded dna copy corresponding to the 5'-nontranslated alpha beta-leader of potato virus x (pvx) genomic rna (positions -3 to-85 according to aug initiator) was chemically synthesized and fused to the transcription plasmids containing three different reporter genes: neomycinphosphotransferase type ii (npt ii) gene, bacillus thuringiensis coleopteran-specific toxic protein gene and beta-glucuronidase (gus) gene. expression of the reporter genes in vitro and in plant protoplasts (in th ... | 1992 | 1537401 |
| the organization of potato virus x coat proteins in virus particles studied by tritium planigraphy and model building. | potato virus x particles containing the intact, undegraded ps form of the coat protein and particles containing the in situ degraded pf form of the coat protein, which is devoid of 19-21 amino acids from the n-terminus, were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the tritium label was studied. the tritium planigraphy revealed that the n-terminal region of the coat protein is the most accessible region for both type of pvx particles. the c-termina ... | 1992 | 1566571 |
| characterization of cymbidium mosaic virus coat protein gene and its expression in transgenic tobacco plants. | cymbidium mosaic virus (cymv) is the most prevalent virus infecting orchids. here, we report the isolation of partial cdna clones encoding the genomic rna of cymv. like most of the polyadenylated monopartite positive-strand rna viruses, the open reading frame (orf) coding for the viral coat protein (cp) is located at the 3' end. the orf predicts a polypeptide chain of 220 amino acids with a molecular weight of 23,600. sequence comparison of this orf to the cp sequences of potato virus x(pvx) and ... | 1992 | 1600145 |
| molecular analysis of a resistance-breaking strain of potato virus x. | full-length cdna clones of potato virus x (pvx) strains pvxuk3 and pvxhb have been constructed in plasmid vectors to allow in vitro transcription of infectious pvx rna. in both instances the transcript-derived virus infected tobacco and potato identically to the respective progenitor strains: in tobacco and susceptible potato cultivars both strains infected systemically, producing symptomless or mild mosaic symptoms. in potato carrying the rx or nx resistance genes, the virus derived from the pv ... | 1992 | 1641981 |
| comparative study of antigenic properties of potato virus x and its coat protein in solution and after adsorption to solid supports. | different elisa procedures were used to compare the antigenic properties of intact potato virus x (pvx) and its dissociated protein. it was found that when the reaction took place in solution (competition elisa), the intact virus reacted with polyclonal antibodies against the intact pvx (ab-pvx) much more strongly than did the dissociated pvx coat protein (pr), and the dissociated protein reacted with the homologous polyclonal antibodies (ab-pr) more strongly than did the intact pvx. however, if ... | 1991 | 1651953 |
| rflp mapping on potato chromosomes of two genes controlling extreme resistance to potato virus x (pvx). | two different chromosomal locations of major genes controlling extreme resistance to potato virus x (pvx) were found by restriction fragment length polymorphism (rflp) analysis of two populations segregating for the resistance. the resistance gene rx1 mapped to the distal end of chromosome xii, whereas rx2 was located at an intermediate position on linkage group v in a region where reduced recombination and segregation distortion have also been observed. these linkage anomalies were due to abnor ... | 1991 | 1675423 |
| translational efficiency and competitive ability of mrnas with 5'-untranslated alpha beta-leader of potato virus x rna. | the 5'-untranslated leader sequence of potato virus x (pvx) rna (63 nucleotides apart from cap-structure) consists of two sub-sequences referred to as alpha-sequence (41 nucleotides with no g) and beta-sequence (42 nucleotides upstream from the first aug). computer-based folding predictions suggest that the 5'-proximal region of alpha beta-leader is unstructured. the second structural feature of alpha beta-leader is the presence of the sequences apparently complementary to the 3'-terminal region ... | 1991 | 1764504 |
| expression strategy of the potato virus x triple gene block. | the mode of expression of the overlapping genes of the triple block positioned internally in potato virus x (pvx) rna was examined. the results of in vitro translation of synthetic rna transcripts and natural pvx-specific methylmercuric hydroxide-denatured dsrnas suggest that the 25k protein is expressed as a single translation product of the 2.1 kb subgenomic (sg) rna and that both the 12k and 8k proteins are expressed from the same 1.4 kb sgrna. | 1991 | 1875198 |
| complete nucleotide sequence of a latin-american isolate of potato virus x. | | 1991 | 1891962 |
| rapid detection of a plant virus by solution hybridization using oligonucleotide probes. | a novel solution hybridization method for the diagnosis of a plant virus was evaluated. synthetic oligonucleotide probes were used for the detection of potato virus x (pvx) in crude leaf sap extracts by hybridization in solution. three 40-nucleotide-long oligonucleotide probes complementary to rna sequences of potato virus x near the 3' end were synthesized. two probes were 32p-labelled and one biotinylated. the three probes were allowed to form hybrids with the target viral nucleic acid in solu ... | 1991 | 1955492 |
| resistance in solanum brevidens to both potato virus y and potato virus x may be associated with slow cell-to-cell spread. | a series of experiments was carried out to investigate the nature of the resistance of the wild potato species, solanum brevidens, to potato virus x (pvx) and potato virus y (pvy). in vitro inoculation of leaf protoplasts of s. brevidens and the virus-susceptible dihaploid s. tuberosum genotype pdh40 with pvx or pvy using polyethylene glycol showed that protoplasts of both species were similar in susceptibility. however, examination of protoplasts prepared from the leaves of s. tuberosum and s. ... | 1991 | 1993865 |
| development and application of a nonradioactive nucleic acid hybridization system for simultaneous detection of four potato pathogens. | cdna clones of potato virus x (pvxcp strain), potato virus y (pvyo strain), potato leaf roll virus (plrv) and potato spindle tuber viroid (pstv) were used separately or combined for the detection of the corresponding rnas in extracts of infected plants. a general method for the rapid preparation of rna extracts without use of organic solvents (i.e. phenol) was developed for this purpose. plant extracts from a range of field, artificially inoculated germplasm genotypes, micro-propagated and proto ... | 1991 | 2016393 |
| replication of potato virus x rna is altered in coinfections with potato virus y. | potato virus x (pvx) and potato virus y (pvy) may coinfect tobacco to cause a classic synergistic disease. in the acute stage the disease is characterized by a dramatic increase in the accumulation of infectious pvx particles, with no corresponding increase or decrease in the accumulation of pvy. the accumulation of pvx genomic rna and coat protein has been examined in doubly versus singly infected tobacco leaves. these experiments indicate that the levels of both viral components increase in do ... | 1991 | 2024486 |
| secondary structures of narcissus mosaic virus coat protein. | circular dichroism (cd) measurements on the coat protein of narcissus mosaic virus particles show that the dominant secondary structure is the alpha-helix, with a 45 (+/- 2)% content. the beta-sheet content is much lower at 5 (+/- 3)%. both values are essentially the same as those found in potato virus x coat protein. the cd results are used to assess the results of secondary structure prediction methods. | 1991 | 2045797 |
| the establishment of rat hybridoma cell lines secreting mcab against strains of potato virus y and analysis of its stability. | the rat splenocytes immunized with potato virus y (pvyn) and ratmyeloma (ir983) were fused by peg (m. w.1450). three kinds of stable hybridoma cell lines secreting specific monoclonal antibodies (mcabs) were derived. one kind of the cell lines producing mcabs reacts to pvyn specifically. another reacts to pvyo specifically. the third one reacts to both of the two strains. tested by the methods of sandwich-elisa and indirect-elisa, all kinds of mcabs did not react to seven plant viruses: tobacco ... | 1990 | 2104212 |
| the use of elisa for detection of the antibody-induced conformational change in a viral protein and its intermolecular spread. | antibody-induced conformational changes of proteins have been recently frequently suggested to explain a variety of observations. in spite of the fundamental importance of this phenomenon for both in vivo and in vitro antigen-antibody interactions, it is not generally accepted because of the lack of conclusive evidence. this report utilizes a novel approach to the study of antibody-induced antigenic conformational changes. pairs of monoclonal antibodies (mab) were used to induce and to assess co ... | 1990 | 2112149 |
| expression of rna transcripts of potato virus x full-length and subgenomic cdnas. | translation of synthetic potato virus x (pvx) rnas was examined in krebs ii ascite cell extracts and rabbit reticulocyte lysates. either full-length or subgenomic rnas produced by in vitro transcription of cdnas cloned in the t7 promoter vectors were used. full-length pvx rna-transcript directed the synthesis of a large polypeptide which was indistinguishable from the translation product (165 kda) of authentic viral genomic rna on sds-page. translation of the full-length and 3'-truncated rna spe ... | 1990 | 2126209 |
| characterization of infectious transcripts from a potato virus x cdna clone. | a full-length cdna clone of potato virus x (pvx) has been constructed and fused to the bacteriophage t7 promoter in an in vitro transcription vector. transcripts derived from this template (pmon 8660) were infectious when inoculated onto the local lesion host, chenopodium amaranticolor. the infectivity of these transcripts was approximately 0.2% that of authentic pvx rna. lesions sampled from plants inoculated with these transcripts contained virus particles and virus aggregates typically observ ... | 1990 | 2139266 |
| [the effect of proteolytic cleavage of potato virus x coat protein on its ability to self-assemble with rna and viral infectivity]. | the process of proteolytic cleavage of potato virus x coat protein molecules inside the virions and in the dissociated state in the course of their purification and storage has been studied. in agreement with the previous reports, the intact form (ps) of the coat protein in the viral particles was found to be gradually cleaved to three discrete lower molecular forms (pi, pf, pu). during the storage of the dissociated coat protein preparations further cleavage was observed with formation of at le ... | 1990 | 2185421 |
| transgenic nicotiana debneyii expressing viral coat protein are resistant to potato virus s infection. | the coat protein gene from potato virus s (pvs) was introduced into nicotiana debneyii by leaf disc transformation using agrobacterium tumefaciens. transgenic plants expressing the viral coat protein were highly resistant to subsequent infection by the me strain of pvs as indicated by an absence of symptom development and a lack of accumulation of virus in both the inoculated and upper leaves. as in reported experiments with plants expressing potato virus x coat protein, plants expressing pvs co ... | 1990 | 2212996 |
| nicotiana velutina mosaic virus: evidence for a bipartite genome comprising 3 kb and 8 kb rnas. | dna complementary to nicotiana velutina mosaic virus (nvmv) rna was cloned and five segments larger than 0.9 kb were used in northern blot hybridization analysis to identify two virus-specific rnas, approximately 8 kb (rna 1) and 3 kb (rna 2) in size. the clones selected as probes did not hybridize with rna from various tobamoviruses, or from beet necrotic yellow vein (bnyvv) and peanut clump furoviruses. in an attempt to determine the taxonomic position of the virus, about 75% of the nvmv rna 2 ... | 1990 | 2345363 |
| complete cdna sequence of a south american isolate of potato virus x. | the complete cdna sequence corresponding to the genomic rna of a south american strain of potato virus x (pvxc) is reported. the sequence (6432 nucleotides) contains five open reading frames coding for polypeptides with molecular weights of 165.3, 24.3, 12.3, 7.6 and 25.0 and displays an overall homology of 77.4% with those previously reported for two european isolates. comparison of amino acid sequences shows an average homology of 87%. two major domains of variability, located between amino ac ... | 1990 | 2392880 |
| antiviral activity of s-adenosylhomocysteine hydrolase inhibitors against plant viruses. | three sah hydrolase inhibitors, (rs)-3-adenin-9-yl-2-hydroxypropanoic acid (isobutyl ester) [(rs)-ahpa]; (rs)-9-(2,3-dihydroxypropyl)adenine [(rs)-dhpa] and the carbocyclic analog of 3-deazaadenosine (c-c3ado) were evaluated for their inhibitory activity against tobacco mosaic virus (tmv) and potato virus x (pvx). using the local lesion assay and elisa, we demonstrated that all three compounds inhibit the replication of tmv and pvx. whereas the three compounds proved about equally active against ... | 1990 | 2396830 |
| engineering virus resistance in agricultural crops. | plant viral genomes are relatively small and in the past decade many have been characterized at the molecular level. this has prompted research into the development of virus resistance based on interference with the viral multiplication cycle by teh introduction of viral sequences into the plant genome. several strategies have been tested. the most successful one so far involves the constitutive expression of the coat protein gene of the virus against which resistance is desired. in this review ... | 1989 | 2485086 |
| establishment of hybridoma cell lines secreting mcas against potato virus x and determination of their physical and chemical characteristics. | splenocytes from balb/c mouse immunized with potato virus x (pvx) and myeloma cells (sp/2) were fused. after cloning and three screening cycles, three hybridoma cell lines secreting strain-specific monoclonal antibodies (mcas) against pvx were obtained. these cell lines were stable for 20 generations and after storage in frozen form (in liquid nitrogen) for one year. the chromosome numbers of the three hybridoma cell lines clustered in the 92-102 range. the mcas all belonged to the igg3 immunogl ... | 1989 | 2491319 |
| probable reassortment of genomic elements among elongated rna-containing plant viruses. | the relationships of genome organization among elongated (rod-shaped and filamentous) plant viruses have been analyzed. sequences in coding and noncoding regions of barley stripe mosaic virus (bsmv) rnas 1, 2, and 3 were compared with those of the monopartite rna genomes of potato virus x (pvx), white clover mosaic virus (wclmv), and tobacco mosaic virus, the bipartite genome of tobacco rattle virus (trv), the quadripartite genome of beet necrotic yellow vein virus (bnyvv), and icosahedral trico ... | 1989 | 2504930 |
| enhanced inhibition of plant virus replication by pyridylthiourea compounds complexed with metal ions. | inhibition of potato virus x replication can be enhanced by complexation of n-allyl-n'-2-pyridyl-thiourea and of n-phenyl-n'-2-pyridyl-thiourea with cu+, zn2+ and cd2+. the antiphytoviral activity of some complexes with pyridylthiourea can be further augmented by adding small quantities of 2,4-dioxohexahydro-1,3,5-triazine. | 1989 | 2508548 |
| effects of ph and ionic strength on precipitation of phytopathogenic viruses by polyethylene glycol. | the effects of ionic strength of the solution (changed by varying nacl concentrations or buffer molarity) on the precipitation with polyethylene glycol (peg) 6000 were studied on phytopathogenic viruses of different morphology: the isometric red clover mottle virus (rcmv), rod-shaped tobacco mosaic virus, flexuous potato virus x (pvx) and bacilliform alfalfa mosaic virus. with increasing nacl concentration or buffer molarity up to a certain level (0.1 mol/l), the efficiency of peg precipitation ... | 1989 | 2565676 |
| simultaneous quantification of two plant viruses by double-label time-resolved immunofluorometric assay. | for simultaneous and sensitive detection of two antigens in one sample, monoclonal antibody (mab) to potato virus m (pvm) was labelled with a lanthanide eu3+ and mab to potato virus x (pvx) with another lanthanide sm3+. a mixture of the labelled mabs was used as a tracer. after performing the immunoreactions, the fluorescence of the dissociated lanthanides was measured at different wave-lengths in a time-resolved fluorometer to quantificate the pvx and pvm amount in a sample. double-label time-r ... | 1989 | 2643612 |
| anomalous electrophoretic behavior of the major potato virus x rna translation product. | the major potato virus x (pvs) rna translation product migrates in laemmli's electrophoresis system as a 210 kda polypeptide ('p210'). if a tris-phosphate-sds buffer system is used instead of a tris-glycine-sds one, the mobility of p210 is higher than that of the largest tmv rna translation product, the 183 kda protein. it is suggested that anomalous electrophoretic behavior of the largest pvx polypeptide during sds-electrophoresis is due to its primary structure, namely to the presence of hydro ... | 1989 | 2723020 |
| nucleotide sequence of narcissus mosaic virus rna. | the nucleotide sequence of the genomic rna of narcissus mosaic virus (nmv) was deduced from a set of cdna clones and by direct sequencing of rna. the genome, with a length of 6955 nucleotides [excluding the 3'poly(a) tail], contains six open reading frames (orfs) with the capacity to code for polypeptides of more than 10k, with mr values of 186284, 25845, 13998, 11059, 26097 and 10519. the first five of these putative proteins show considerable homology to similar proteins encoded by the rnas of ... | 1989 | 2732689 |
| organization and interviral homologies of the 3'-terminal portion of potato virus s rna. | the sequence of 3553 nucleotides corresponding to the 3'-terminal region of potato virus s (pvs) has been determined from cloned cdna. the sequence obtained contains six open reading frames (orfs) encoding proteins of mr 10,734, mr 32,515, mr 7,222, mr 11,802, mr 25,092 and at least mr 41,052. the sequence of the 33k orf has been confirmed to be that of the viral coat protein gene. the nucleotide sequence of this orf was obtained from plasmids which were isolated by colony hybridization with a s ... | 1989 | 2732711 |
| [use of a cell-free protein synthesizing system from cells of ascites carcinoma krebs-2 for rna translation of plant viruses]. | cell-free translation in krebs-2 extracts was optimized for rnas of two plant viruses; potato virus x (pvx, potexvirus), and tobacco mosaic virus (tmv, tobamovirus). pvx and tmv rnas programmed synthesis of similar sets of polypeptides in both the krebs-2 extracts and the rabbit reticulocyte lysates, major virus-specific products being the same in molecular weight in both in vitro systems. pvx structural protein (p29) was absent among polypeptides synthesized in the krebs-2 system but was readil ... | 1989 | 2739641 |
| [comparison of antigenic properties of the x-potato virus and its coat proteins. effect of proteolytic cleavage on antigenic characteristics]. | antigenic properties of intact potato virus x (pvx) particles and of pvx coat protein (cp) preparations were compared using different modifications of elisa test. in the competitive elisa test (reaction in solution) antibodies to intact virus react much stronger with pvx than with cp while antibodies to cp react much stronger with cp than with pvx. in the direct elisa test (reaction on the solid support) the difference in reactions of anticp antibodies with pvx and cp is eliminated while the one ... | 1989 | 2739670 |
| on the inhibition of plant virus multiplication by ribavirin. | the inhibition of the replication of potato virus x (pvx), belladonna mottle virus, tobacco mosaic virus, potato virus y (pvy), and tobacco necrosis virus by ribavirin and pyrazofurin is described with emphasis on the inhibition of pvx by ribavirin. ribavirin inhibits an early step of pvx replication. the inhibition is reversed to different degrees by all ribo- and deoxyribonucleosides, most strongly by thymidine. in tobacco leaves, nucleosides compete with ribavirin for phosphorylation to monop ... | 1987 | 2821895 |
| translation arrest of potato virus x rna in krebs-2 cell-free system: rnase h cleavage promoted by complementary oligodeoxynucleotides. | translation arrest of genomic potato virus x (pvx) rna promoted by complementary oligodeoxynucleotides in krebs-2 cell-free system is described. 14-15 mer oligodeoxynucleotides complementary to the 5'-proximal cistron of pvx rna were shown to induce specific truncation of the major non-structural polypeptide coded by pvx rna. evidence is presented that effective translational arrest of pvx rna in the presence of complementary oligonucleotides results from the site-specific cleavage of rna by end ... | 1988 | 2839367 |
| [primary structure of the potato virus x genome: the region preceding the capsid protein cistron]. | dna copies of the potato virus x (pvx) rna corresponding to 2300 nucleotides at the 3'-end have been cloned. the cloned cdna copies containing the nucleotides 445-1280 from the 3'-end have been sequenced. the 5'-terminal region of the pvx coat protein gene corresponds to residues 445-786 from the 3'-end. the amino acid sequences of two more open reading frames (orf) have been deduced from the nucleotide sequence. the potential translation products of these orf's would correspond to the nonstruct ... | 1987 | 3033484 |
| purified scrapie prions resist inactivation by procedures that hydrolyze, modify, or shear nucleic acids. | prions were purified from scrapie-infected hamster brains and incubated for 24 hr at 65 degrees with 2 mm zn2+ or 5 mm mg2+; no loss of infectivity was observed. bacteriophage m13, tobacco mosaic virus (tmv), potato virus x, and potato spindle tuber viroid were all inactivated by divalent metal ions under these conditions. prions also resisted inactivation by prolonged digestions with dnase i, rnases a and t1, and micrococcal nuclease. prions were resistant to psoralen photoadduct formation usin ... | 1987 | 3114950 |
| [primary structure and organization of the genome of potato virus x]. | | 1988 | 3168736 |
| conserved and variable elements in rna genomes of potexviruses. | the nucleotide sequences of genomic rnas and predicted amino acid sequences of two strains of potato virus x and white clover mosaic potexvirus were compared to each other, and the proteins of different plus-rna-containing plant viruses. the predicted non-virion proteins of potexviruses have direct sequence homology and common structural peculiarities with those of several 'sindbis-like' plant viruses. the most conserved amino acid sequences were found to be located in the polypeptide encoded by ... | 1988 | 3191997 |
| the nucleotide sequence of potato virus x rna. | | 1988 | 3205733 |
| biotinylated nucleic acid hybridization probes for potato virus detection. | cdna libraries, representative of potato viruses x (pvxc strain) and y (pvy degrees strain) genomes were obtained. a pvx cdna cloned fragment was sequenced and biotinylated to be used as hybridization probe for the detection of purified virus or nucleic acid extracts of infected plants. dot hybridization assay was sensitive to detect 4 ng of viral particles, corresponding to about 200 pg of viral rna. the level of detection in infected plant extracts was as effective as that obtained with the el ... | 1988 | 3214274 |
| inhibitory effects of 9-(2,3-dihydroxypropyl)adenine and 3-(adenin-9-yl)-2-hydroxypropanoic acid 2-methylpropylester on potato virus x replication. | 9-(2,3-dihydroxypropyl)adenine (dhpa) and 3-(adenin-9-yl)-2-hydroxypropanoic acid 2-methylpropylester (ahpa-mp)) markedly inhibit the replication of potato virus x (pvx). the latter compound inhibits virus replication more effectively at the lower concentration range. in synchronized virus-infected leaf-disks, the time-response course of inhibition by both compounds is almost identical, and similar to that of cycloheximide. | 1988 | 3218979 |
| the complete nucleotide sequence of potato virus x and its homologies at the amino acid level with various plus-stranded rna viruses. | double-stranded cdna of potato virus x (pvx) genomic rna has been cloned and sequenced. the sequence [6435 nucleotides excluding the poly(a) tract] revealed five open reading frames (orfs) which were numbered one to five starting at the 5' terminus of the rna. they encoded proteins of mr 165588 (166k), 24622 (25k), 12324 (12k), 7595 (8k) and 25080 (coat protein), respectively. orfs 1 and 2 were inphase coding regions. the orf 1 product contained domains of homology with the tobacco mosaic virus ... | 1988 | 3404114 |
| antiviral effects of dihydroxypropyladenine [rs)-dhpa) and bromovinyldeoxyuridine (bvdu) on plant viruses. | two established antiviral agents, dihydroxypropyladenine (rs)-dhpa and bromovinyldeoxyuridine (bvdu) were evaluated for their inhibitory effects on 4 plant viruses: tobacco mosaic virus, potato virus x (pvx), eggplant mosaic virus (emv) and a potyvirus isolated from solanum palinacanthum (poty-sp). using the leaf disc incubation test, bvdu proved virtually inactive while (rs)-dhpa efficiently inhibited emv and poty-sp when applied at concentrations as low as 5 mg/l. tmv was less susceptible to t ... | 1987 | 3446016 |
| [difference in the mechanism of self-assembly in vitro in tobacco mosaic virus and potato virus x]. | the effects of 254 nm uv-irradiation of tobacco mosaic virus (tmv) and potato virus x (pvx) rna preparations on the rna ability to self-assembly in vitro with the viral coat proteins were studied. it was found that while tmv rna ability to assemble with the homologous protein is rapidly inactivated by the uv-irradiation, pvx rna ability to be encapsidated by the pvx coat protein is quite resistant to the irradiation. more than that, the irradiation of tmv rna with the dose strongly inhibiting it ... | 1987 | 3447057 |
| analogues of pyrimidine base precursors as antiphytoviral agents. | dihydroorotic acid hydrazide (dhoh) did not inhibit the replication of potatovirus x (pvx) in leaf disks of nicotiana tabacum 'samsun'. in contrast, 5-fluoroorotic acid (5-foa) completely inhibited the replication of pvx, as demonstrated by a serological virus assay as well as a local lesion bioassay using gomphrena globosa as the test plant. the corresponding base analogue 5-fluorouracil (5-fu) had only a weak inhibitory effect. time-course inhibition experiments in synchronized virus-infected ... | 1987 | 3606085 |
| expression of resistance to potato virus x in isolated potato protoplasts. | resistance to potato virus x (pvx) in potato cultivars is conferred by the genes nx and/or nb. the nx gene is activated by group 3 strains of pvx. when protoplasts from the cultivars king edward containing the nx gene and pentland crown containing neither resistance gene were inoculated with a group 3 strain of pvx resistance was expressed in the king edward protoplasts. replication of pvx occurred in king edward protoplasts but only at a very low level as compared with the level observed in the ... | 1986 | 3707357 |
| optimisation of conditions for infection of isolated potato protoplasts with potato virus x. | conditions for the reproducible infection of potato protoplasts with pvx were determined. successful virus infection was achieved when potato protoplasts at a concentration of 3 x 10(5) cells/ml were incubated with 20 micrograms/ml pvx and 2 micrograms/ml poly-l-ornithine (mw 100,000) for 15 minutes at 0 degrees c. numbers of protoplasts infected varied between 30 and 50 per cent. preincubation of pvx with plo for a minimum of 10 minutes was essential for good infection. the type and molecular w ... | 1985 | 4026583 |
| comparison of the effects of chlorite-oxidized oxyamylose and polyacrylic acid on the multiplication of phytopathogenic viruses. | polyacrylic acid (paa) and chlorite-oxidized oxyamylose (coam) inhibit the multiplication of tobacco mosaic virus (tmv) in leaf disks by up to 50%. the reduction in tmv content is time-dependent and decreases with longer time intervals between the virus infection and the application of substances. the multiplication of potato virus x (pvx) in leaf disks is not affected by either paa or coam. in intact plants paa produces a strong antiviral effect on both pvx and red clover mottle virus (rcmv). t ... | 1985 | 4062284 |
| an antigenic analysis of potato virus x and of its degraded protein. ii. evidence for a conformational change associated with the depolymerization of structural protein. | | 1970 | 4099083 |
| electron microscopy of potato meristem tips infected with potato virus x. | | 1972 | 4112038 |
| potato virus x in potato apical meristems. | | 1973 | 4120870 |
| effect of actinomycin d on potato virus x multiplication in datura stramonium leaves. | | 1973 | 4350225 |
| chemical modification of the lysine-amino groups of potato virus x. | | 1974 | 4436657 |
| effect of nickel on multiplication of potato virus x in tomato plant. | | 1974 | 4442527 |
| photoreactivation of tobacco mosaic virus and potato virus x ribonucleic acids inactivated by acetone-sensitized photoreaction. | | 1972 | 4555071 |
| enhancement of potato virus x synthesis in doubly infected tobacco occurs in doubly infected cells. | | 1974 | 4595376 |
| the structure and antigenic analysis of amorphous inclusion bodies induced by potato virus x. | | 1972 | 4627341 |