| a technique for the differential isolation of hop mosaic virus and hop latent virus. | two rod-shaped viruses of similar length occurring in hops were isolated from a mixed infection. one (hop mosaic virus) infected nicotiana clevelandii, produced mosaic symptoms in mosaic-sensitive hop cultivars, and did not infect chenopodium murale. the other (hop latent virus) infected c. murale but not n. clevelandii and did not produce mosaic symptoms in hops. neither n. clevelandii nor c. murale developed distinct symptoms after infection with the respective virus. both viruses produced a s ... | 1976 | 986870 |
| cytological evidence supporting the inclusion of poplar mosaic virus in the carlavirus group of plant viruses. | the filamentous particles of poplar mosaic virus (popmv) were detected in palisade, mesophyll and parenchyma cells of systemically infected leaves of nicotiana clevelandii and n. megalosiphon. the particles were sometimes found scattered throughout the cytoplasm, but more often they occurred loosely associated within ovoid aggregates (up to 3.5 x 1.5 mum) adjacent to chloroplasts and/or mitochondria. popmv did not induce the formation of 'pinwheel' inclusions, nor other conspicuous ultrastructur ... | 1976 | 1010717 |
| 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 replication of cymbidium ringspot tombusvirus defective interfering-satellite rna hybrid molecules. | a dna copy of di rna of cymbidium ringspot tombusvirus was cloned downstream of a phage t7 promoter. in vitro-transcribed rna replicated in nicotiana clevelandii when co-inoculated with full-length viral genomic rna transcripts and protected plants from apical necrosis. artificial deletion mutants derived from the di rna clone showed that most of the central sequence block is necessary for replication. hybrid di rna-satrna clones were prepared and in vitro-synthesized rna was inoculated to plant ... | 1992 | 1381535 |
| replication and movement of a coat protein mutant of cymbidium ringspot tombusvirus. | the spread of cymbidium ringspot tombusvirus (cyrsv) in host tissue was studied by using a coat protein gene mutant with a six-nucleotide deletion; the deletion removes two amino acids from the shell domain (s) of the capsid protein. mutated protein subunits were synthesized in infected cells but could not assemble into virus particles. virions were formed, however, with inoculation of mutated rna in transgenic plants expressing normal cyrsv coat protein. the mutant is restricted in long-distanc ... | 1992 | 1472715 |
| regulation of the activities of african cassava mosaic virus promoters by the ac1, ac2, and ac3 gene products. | dna fragments comprising each of the promoter regions from the geminivirus african cassava mosaic virus (acmv) were cloned into the puc18-based vector, pg1, producing transcriptional fusions with the beta-glucuronidase gene (gus) and nopaline synthase terminator sequence. the relative activity of each promoter construct was analyzed by a gus expression assay of extracts from nicotiana clevelandii protoplasts coelectroporated with the gus reporter constructs and constructs in which individual acm ... | 1992 | 1585657 |
| virus-specific proteins in cells infected with tomato black ring nepovirus: evidence for proteolytic processing in vivo. | the synthesis of proteins encoded by the rna of tomato black ring virus (tbrv) in vivo was studied in protoplasts by direct labelling with [35s]methionine, and in protoplasts and plants by immunoblotting experiments with specific antisera. comparison of the proteins synthesized in infected and mock-inoculated protoplasts suggested that proteins of m(r) 120k, 90k, 80k, 57k and 46k were virus-specific. the proteins derived from the rna-1-encoded polyprotein detected by immunoblotting were a stable ... | 1992 | 1629691 |
| change in phenotype and encapsidated rna segments of an isolate of alfalfa mosaic virus: an influence of host passage. | a local lesion isolate of alfalfa mosaic virus (amv-n20) from lucerne was found to encapsidate two extra rnas in addition to the four major rnas (rna1, -2, -3 and -4). these were resolved by gel electrophoresis both under native conditions and after glyoxal denaturation. the rna with an electrophoretic mobility between that of rnas 2 and 3 was designated rna31, that between rnas 3 and 4 was designated rna3s. sucrose density gradient centrifugation analysis of amv-n20 showed six instead of the no ... | 1991 | 1765766 |
| sensitivity and specificity of nucleic acid probes for potato leafroll luteovirus detection. | complementary dna (cdna) probes, prepared by nick-translation or by oligolabelling of a 520 bp fragment representing residues 4741 to 5261 in the potato leafroll luteovirus (plrv) sequence, were equally sensitive, with a detection limit equivalent to sap from about 600 micrograms of infected potato or nicotiana clevelandii leaf tissue and to rna from about 120 micrograms tissue. increasing the concentration of oligolabelled probe gave similar results with shorter autoradiographic exposures, but ... | 1991 | 1804851 |
| nuclear location of the 16k non-structural protein of tobacco rattle virus. | an antiserum, elicited by a synthetic peptide coupled to bovine serum albumin, reacted specifically with the non-structural 16k protein of tobacco rattle virus. the protein was detected in extracts of systemically infected nicotiana clevelandii leaves, but only in those made with the aid of sds, urea and 2-mercaptoethanol. immunogold labelling of ultrathin sections showed that the protein was mainly associated with nuclei, but was also present in the cytoplasm. these observations suggest that th ... | 1991 | 1831493 |
| analysis of the potential promoter sequences of african cassava mosaic virus by transient expression of the beta-glucuronidase gene. | dna fragments from promoter regions of the geminivirus, african cassava mosaic virus, were cloned into pg1, a vector based on puc18, producing transcriptional fusions with the beta-glucuronidase (gus) gene and nopaline synthase termination sequence. the activity of each promoter construct was assessed by analysing the transient expression of gus in nicotiana clevelandii protoplasts. the results demonstrated that constructs containing the common region of dna a showed much stronger promoter activ ... | 1991 | 1940874 |
| detection of the movement protein of red clover necrotic mosaic virus in a cell wall fraction from infected nicotiana clevelandii plants. | the movement protein of red clover necrotic mosaic virus (rcnmv) was expressed in escherichia coli as a fusion with a maltose-binding protein using the vector pmal-cri and used to produce an antiserum. the rcnmv movement protein was detected in a cell wall fraction obtained from infected nicotiana clevelandii leaf tissue by immunoblotting using the movement protein antiserum. the movement protein could be detected 6 h after inoculation and reached a maximum after 24 h. in contrast, the virus cap ... | 1991 | 1940875 |
| de novo generation of cymbidium ringspot virus defective interfering rna. | nicotiana clevelandii plants were inoculated with cymbidium ringspot tombusvirus rna synthesized in vitro, after which further passages were made by sap inoculation. during the third passage, low mr rna species appeared which had the characteristics of deletion mutants of genomic rna. sequence analysis of several of these defective interfering rnas suggested a possible evolution of smaller from larger molecules. computer-generated secondary structures of sequences surrounding recombination sites ... | 1991 | 2005430 |
| infectious transcripts from cloned cucumber necrosis virus cdna: evidence for a bifunctional subgenomic mrna. | highly infectious synthetic transcripts from full-length cucumber necrosis virus (cnv) cdna clones have been prepared. infections produced by these transcripts, by cnv rna, and by mutated transcripts are compared. inoculation with natural cnv rna resulted in a mild systemic necrosis in nicotiana clevelandii, whereas inoculation with synthetic cnv transcripts resulted in severe systemic necrosis. an abundant low molecular weight rna species was associated with cnv rna infections but was not detec ... | 1991 | 2014641 |
| plum pox potyvirus rna replication in a crude membrane fraction from infected nicotiana clevelandii leaves. | in vitro synthesis of plum pox potyvirus (ppv)-specific nucleic acid has been measured in a crude fraction prepared from leaves of ppv-infected nicotiana clevelandii plants. using alkali and dnase treatments, the synthesized nucleic acid was shown to be rna. the electrophoretic mobility and the differing sensitivity to rnase at high and low salt concentrations allowed the identification of in vitro products probably corresponding to replicative form and replicative intermediate rna, as well as t ... | 1991 | 2016593 |
| infectious in vitro transcripts from a plum pox potyvirus cdna clone. | a full-length cdna clone of the 9786 nt plum pox virus (ppv) rna genome has been cloned downstream from a phage t7 rna polymerase promoter. the rnas synthesized by in vitro run-off transcription in the presence of the 5' cap analog m7gpppg were infectious in nicotiana clevelandii plants. no infectivity was detected when the transcriptions were carried out in the absence of the cap analog. inoculations of the local lesion host chenopodium foetidum indicated that the infectivity of the synthetic t ... | 1990 | 2371774 |
| kinetics of velvet tobacco mottle virus satellite rna synthesis and encapsidation. | synthesis of circular (rna 2) and linear (rna 3) molecules of velvet tobacco mottle virus (vtmov) satellite rna (sat rna) has been studied by incubating strips of tissues excised from systemically infected nicotiana clevelandii in solutions of [14c]uridine. after a short lag, rna and virus synthesis proceeded at a constant rate for at least 24 hr, during which time most of the synthesis was directed to the production of rnas 2 and 3. the kinetics of [14c]uridine incorporation into the sat rna mo ... | 1989 | 2718388 |
| cytopathology in the identification and classification of tombusviruses. | ten recognized members of the tombusvirus group, including two strains of tomato bushy stunt virus, were compared for their ultrastructural effects in nicotiana clevelandii, gomphrena globosa, and chenopodium quinoa. the cytopathic inclusions known as multivesicular bodies and tonoplast evaginations containing virus particles were induced by all the viruses in all three hosts. some of the viruses could be differentiated from each other (especially in c. quinoa) by other characters, such as the a ... | 1987 | 3450676 |
| effects of cycloheximide on the accumulation of tobacco rattle virus in leaf discs of nicotiana clevelandii. | | 1971 | 5166271 |
| intracellular occurrence of cowpea mild mottle virus in two unrelated plant species. | the filamentous particles of cowpea mild mottle virus (cmmv) were detected only in the cytoplasm of palisade, mesophyll, parenchyma and epidermal cells of glycine max (papilionaceae) and nicotiana clevelandii (solanaceae). they were aggregated to form either sheets or bundles or, more frequently, brush-like inclusions. although cmmv was initially considered to be a possible member of the carlavirus group, it differs from aphid-borne carlaviruses in its intracellular occurrence and transmission b ... | 1983 | 6629699 |
| the fine structure of cymbidium ringspot virus infections in host tissues. iii. role of peroxisomes in the genesis of multivesicular bodies. | ultrastructural studies of nicotiana clevelandii plants systemically infected with cymbidium ringspot virus, a member of the tombusvirus group, have shown that a clear-cut relationship exists between perioxisomes and multivesicular bodies (mvb). in infected cells, peroxisomes undergo a progressive vesiculation of the bounding membrane through the possible addition of membranous material by the endoplasmic reticulum and become very plastic. portions of the ground cytoplasm are engulfed either thr ... | 1983 | 6848773 |
| tomato bushy stunt virus spread is regulated by two nested genes that function in cell-to-cell movement and host-dependent systemic invasion. | we have investigated the importance of two small nested genes (p19 and p22) located near the 3' end of the genome of tomato bushy stunt virus (tbsv) for infectivity in several hosts. our results show that both genes are dispensable for replication and transcription and that the p19 gene encodes a soluble protein, whereas the p22 gene specifies a membrane-associated protein. assays using tbsv derivatives that have the beta-glucuronidase gene substituted for the capsid protein gene demonstrate tha ... | 1995 | 7491767 |
| characterization and subcellular localization of tomato ringspot nepovirus putative movement protein. | sequence comparison of the tomato ringspot nepovirus (tomrsv) genome with related viruses suggested that the region of the rna-2-encoded polyprotein immediately upstream of the coat protein may be involved in the cell-to-cell movement of the virus (rott et al., 1991, j. gen. virol. 72, 1505-1514). to further study the role of this portion of the genome, monoclonal antibodies against the putative movement protein were raised. western blots of plant extracts allowed the detection of a viral nonstr ... | 1993 | 7684875 |
| consequences of gene transfer between distantly related tombusviruses. | hybrid cdna clones were constructed by fusing the coat protein-encoding gene and/or the 3'-terminal region (including the 22- and 19-kda protein-encoding genes) derived from a clone of artichoke mottled crinkle tombusvirus to the 5'-terminal region of a full-length clone of cymbidium ringspot tombusvirus. in vitro transcripts from recombinant clones were infectious when inoculated into nicotiana clevelandii plants. inoculated plants showed symptoms different from those induced by parent viruses. ... | 1993 | 7686869 |
| isolation and characterization of an rna-dependent rna polymerase from nicotiana clevelandii plants infected with red clover necrotic mosaic dianthovirus. | a template-bound rna polymerase was isolated from nicotiana clevelandii plants infected with red clover necrotic mosaic dianthovirus (rcnmv) by differential centrifugation, solubilization with dodecyl beta-d-maltopyranoside, and chromatography on columns of sephacryl s-400 and q-sepharose. analysis of the purified polymerase by sds-polyacrylamide gel electrophoresis, followed by silver staining or immunoblotting, showed that it contained virus-encoded proteins of molecular masses 27 kda and 88 k ... | 1995 | 7782776 |
| generation of defective interfering rna dimers of cymbidium ringspot tombusvirus. | inoculation of nicotiana clevelandii and n. benthamiana plants with in vitro transcripts of both genomic and defective interfering (di) rnas of cymbidium ringspot tombusvirus resulted in a rapid accumulation of new di-like rna species which were demonstrated by cloning and sequencing to be head-to-tail dimers of unit length di rnas. the junction regions of dimers were represented by sequences derived precisely from the 5' and 3' termini of di rnas. only infection with di rnas of smaller size (di ... | 1995 | 7886955 |
| cell-to-cell movement of potato virus x revealed by micro-injection of a viral vector tagged with the beta-glucuronidase gene. | the replication and cell-to-cell movement of potato virus x (pvx) has been studied using a pvx vector construct which expressed the beta-glucuronidase (gus) reporter gene in infected cells. nicotiana clevelandii leaf trichome cells were micro-injected with the pvx-gus vector and histochemical staining was used to locate gus activity. the distribution of gus activity revealed that pvx had moved from the injected cell into other trichome cells and into the cells along the leaf margin. gus activity ... | 1995 | 7894504 |
| electron microscopic and molecular characterization of turnip vein-clearing virus. | we recently isolated turnip vein-clearing virus (tvcv), a tobamovirus which causes vein clearing in brassica rapa (turnip) and a mosaic in nicotiana tabacum (tobacco). we present an electron microscopic and molecular characterization of tvcv. viral particles from lower epidermis peel contained rod-shaped viral particles, typical of tobamoviruses. viral rna extracted from infected turnip leaves was used as template for cdna synthesis prior to cloning in a plasmid vector. inserts of selected cdna ... | 1994 | 7998835 |
| de novo generation and accumulation of tomato bushy stunt virus defective interfering rnas without serial host passage. | studies were initiated to monitor generation and accumulation of defective interfering (di) rnas associated with tomato bushy stunt virus (tbsv) in the absence of serial, high multiplicity of infection passage. infections were initiated in nicotiana clevelandii host plants and protoplast cell suspensions by inoculation with in vitro-synthesized infectious tbsv rna transcripts containing a genomic marker. the infections were then assayed for di-size rnas by both northern blot analysis and reverse ... | 1994 | 8259674 |
| extreme resistance to potato virus x infection in plants expressing a modified component of the putative viral replicase. | three types of mutation were introduced into the sequence encoding the gdd motif of the putative replicase component of potato virus x (pvx). all three mutations rendered the viral genome completely noninfectious when inoculated into nicotiana clevelandii or into protoplasts of nicotiana tabacum (cv. samsun nn). in order to test whether these negative mutations could inactivate the viral genome in trans, the mutant genes were expressed in transformed n.tabacum (cv. samsun nn) under control of th ... | 1993 | 8440232 |
| symptomatology and movement of a cucumber necrosis virus mutant lacking the coat protein protruding domain. | a cucumber necrosis virus (cnv) mutant which lacks the coding sequence for the coat protein protruding domain, pd(-), was constructed by site-directed mutagenesis of an infectious cnv cdna clone, pk2/m5 (wild-type, 4701 nt). transcripts of pd(-) were infectious on nicotiana clevelandii; however, local lesions produced were significantly smaller than those on the corresponding leaves of plants inoculated with wild-type transcript. in addition, systemic symptoms took 8 to 12 days longer to develop ... | 1993 | 8460495 |
| polypeptide synthesis induced in nicotiana clevelandii protoplasts by infection with raspberry ringspot nepovirus. | infection of nicotiana clevelandii protoplasts by raspberry ringspot nepovirus resulted in the accumulation of about 24 polypeptides that differed in m(r) and pi from polypeptides accumulating in mock-inoculated protoplasts. similar polypeptides accumulated in protoplasts infected with the s and e strains of rrv but different infection-specific polypeptides were detected in protoplasts infected with tobacco ringspot nepovirus. the m(r) of rrv-specific polypeptides ranged from 210,000 to 18,000 a ... | 1993 | 8470949 |
| cell-to-cell movement of potato virus x is associated with a change in the size-exclusion limit of plasmodesmata in trichome cells of nicotiana clevelandii. | to study the effect of cell-to-cell movement of potato virus x (pvx) on the size-exclusion limit of plasmodesmata we have microinjected virus particles and fluorescently labelled dextrans (f-dextrans) with average molecular mass of 4.4, 10, and 20 kda into nicotiana clevelandii trichome cells. a vector construct of pvx expressing gus (pvx.gus) moved from the injected cell and modified the plasmodesmata to allow passage of the 4.4- and 10-kda f-dextrans but not the 20-kda f-dextran. a mutant pvx ... | 1996 | 8614986 |
| tobacco mosaic virus movement protein-mediated protein transport between trichome cells. | tobacco mosaic virus movement protein (tmv mp) is required to mediate viral spread between plant cells via plasmodesmata. plasmodesmata are cytoplasmic bridges that connect individual plant cells and ordinarily limit molecular diffusion to small molecules and metabolites with a molecular mass up to 1 kd. here, we characterize functional properties of nicotiana clevelandii trichome plasmodesmata and analyze their interaction with tmv mp. trichomes constitute a linear cellular system and provide a ... | 1995 | 8718620 |
| processing of the plum pox virus polyprotein at the p3-6k1 junction is not required for virus viability. | proteolytic processing of the potyvirus polyprotein is mainly performed by the virus-encoded nia protease, whose cleavage sites are characterized by conserved heptapeptide sequences. partial processing at the cleavage site present between the p3 and 6k1 cistrons by the plum pox potyvirus (ppv) nia protease has been previously shown to occur in vitro. we have now studied the role of polyprotein processing at the p3-6k1 junction in vivo, using a full-length ppv cdna clone. ppv mutant transcripts c ... | 1995 | 9049341 |
| effects of mutations in the beet western yellows virus readthrough protein on its expression and packaging and on virus accumulation, symptoms, and aphid transmission. | virions of beet western yellows luteovirus contain a major capsid protein (p22.5) and a minor readthrough protein (p74), produced by translational readthrough of the major capsid protein sequence into the neighboring open reading frame, which encodes the readthrough domain (rtd). the rtd contains determinants required for efficient virus accumulation in agroinfected plants and for aphid transmission. the c-terminal halves of the rtd are not well conserved among luteoviruses but the n-terminal ha ... | 1997 | 9143288 |
| mutation of the gks motif of the rna-dependent rna polymerase from potato virus x disables or eliminates virus replication. | the rna-dependent rna polymerase (rdrp) of potato virus x (pvx) contains a glycine-lysine-serine (gks) motif. this motif is present in the replication enzyme of many rna viruses and is thought to be required for nucleoside triphosphate-binding. three single amino acid changes, glycine to alanine (aks), lysine to asparagine (gns) and lysine to glutamate (ges) within the gks motif of the pvx rdrp were tested for their effect on pvx accumulation. the gns and ges mutations rendered the virus unable ... | 1997 | 9191915 |
| long sequences in the 5' noncoding region of plum pox virus are not necessary for viral infectivity but contribute to viral competitiveness and pathogenesis. | the 5'-terminal 31 nucleotides of the 146-nucleotides-long 5' noncoding region of plum pox potyvirus (ppv) are highly conserved in all the members of the potyvirus genus. to map the sequences of the 5' noncoding region that are necessary in vivo for infectivity, we have constructed a nested set of substitution and deletion mutants. while we were not able to infect nicotiana clevelandii plants with full-length ppv transcripts bearing mutations in the 5'-terminal 35 nucleotides of the viral genome ... | 1997 | 9201225 |
| host-controlled cell-to-cell movement of a hybrid barley stripe mosaic virus expressing a dianthovirus movement protein. | the triple gene block (tgb) of barley stripe mosaic virus (bsmv), coding for viral movement proteins (mps), was replaced by the single mp gene of red clover necrotic mosaic virus (rcnmv). accumulation of the hybrid virus in barley plants (the selective host for bsmv) was reduced compared to bsmv. the hybrid virus induced small necrotic local lesions on chenopodium amaranticolor leaves and did not infect nicotiana clevelandii (the selective host for rcnmv). the hybrid virus accumulated in the ino ... | 1997 | 9268764 |
| ultrastructural analysis of leaf trichome plasmodesmata reveals major differences from mesophyll plasmodesmata. | functional studies on molecular transport through plasmodesmata in leaf mesophyll and trichome cells revealed significant differences in their basal size-exclusion limits and their response to microinjected tobacco mosaic virus movement protein (e. waigmann et al., 1994, proc. natl. acad. sci. usa 91: 1433-1437; e. waigmann and p. zambryski, 1995, plant cell 7; 2069-2079). to address the basis for these functional differences, nicotiana clevelandii trichome and mesophyll plasmodesmata were compa ... | 1997 | 9299792 |
| new satellite rnas, but no di rnas, are found in natural populations of tomato bushy stunt tombusvirus. | a collection of 57 field isolates of the tombusvirus tomato bushy stunt virus was obtained from eggplant and tomato during 1994-1997 and was examined for the presence of defective interfering (di) rna species by northern blot hybridization and rt-pcr. no di rna species were detected associated with any of the field tbsv isolates. however, serial passaging of two field isolates in nicotiana clevelandii at high multiplicity of infection resulted in the rapid generation of di-like rna species, indi ... | 1997 | 9434719 |
| the movement protein of cucumber mosaic virus traffics into sieve elements in minor veins of nicotiana clevelandii | the location of the 3a movement protein (mp) of cucumber mosaic virus (cmv) was studied by quantitative immunogold labeling of the wild-type 3a mp in leaves of nicotiana clevelandii infected by cmv as well as by using a 3a-green fluorescent protein (gfp) fusion expressed from a potato virus x (pvx) vector. whether expressed from cmv or pvx, the 3a mp targeted plasmodesmata and accumulated in the central cavity of the pore. within minor veins, the most extensively labeled plasmodesmata were those ... | 1998 | 9548980 |
| development of an antigen presentation system based on plum pox potyvirus. | the development of an antigen presentation system based on the plum pox potyvirus (ppv) is here described. the amino-terminal part of ppv capsid protein was chosen as the site for expression of foreign antigenic peptides. modifications in this site were engineered to avoid the capability of natural transmission by aphids of this ppv vector. as a first practical attempt, different forms of an antigenic peptide (single and tandem repetition) from the vp2 capsid protein of canine parvovirus (cpv) w ... | 1998 | 9607317 |
| correlation between binding affinity and necrosis-inducing activity of mutant avr9 peptide elicitors. | the race-specific peptide elicitor avr9 of the fungus cladosporium fulvum induces a hypersensitive response only in tomato (lycopersicon esculentum) plants carrying the complementary resistance gene cf-9 (moneymaker-cf9). a binding site for avr9 is present on the plasma membranes of both resistant and susceptible tomato genotypes. we used mutant avr9 peptides to determine the relationship between elicitor activity of these peptides and their affinity to the binding site in the membranes of tomat ... | 1998 | 9625714 |
| a cloned erwinia chrysanthemi hrp (type iii protein secretion) system functions in escherichia coli to deliver pseudomonas syringae avr signals to plant cells and to secrete avr proteins in culture. | the hrp (type iii protein secretion) system is essential for the plant parasitic ability of pseudomonas syringae and most gram-negative bacterial plant pathogens. avrb and avrpto are two p. syringae proteins that have biological activity when produced via heterologous gene expression inside plant cells or when produced by hrp+ bacteria. avr-like proteins, presumably injected by the hrp system on bacterial contact with plant cells, appear to underlie pathogenic interactions, but none has been obs ... | 1998 | 9707625 |
| stacks on tracks: the plant golgi apparatus traffics on an actin/er network. | we have visualized the relationship between the endoplasmic reticulum (er) and golgi in leaf cells of nicotiana clevelandii by expression of two golgi proteins fused to green fluorescent protein (gfp). a fusion of the transmembrane domain (signal anchor sequence) of a rat sialyl transferase to gfp was targeted to the golgi stacks. a second construct that expressed the arabidopsis h/kdel receptor homologue aerd2, fused to gfp, was targeted to both the golgi apparatus and er, allowing the relation ... | 1998 | 9750355 |
| production of a functional single chain antibody attached to the surface of a plant virus. | a potato virus x (pvx) vector was used to express a single chain antibody fragment (scfv) against the herbicide diuron, as a fusion to the viral coat protein. the modified virus accumulated in inoculated nicotiana clevelandii plants and assembled to give virus particles carrying the antibody fragment. electron microscopy was used to show that virus particles from infected leaf sap were specifically trapped on grids coated with a diuron-bsa conjugate. the results demonstrate that the pvx vector c ... | 1998 | 9891975 |
| role of the beet western yellows virus readthrough protein in virus movement in nicotiana clevelandii. | luteoviruses such as beet western yellows polerovirus (bwyv) are confined to and multiply within the phloem compartment of their hosts. the readthrough domain (rtd) of the minor bwyv capsid protein p74 is required for efficient virus accumulation in nicotiana clevelandii. experiments were carried out to determine if the low virus titres observed following agro-inoculation of whole plants with certain rtd mutants are due to a defect in virus multiplication in the nucleate cells of the phloem comp ... | 1999 | 10573174 |
| rapid production of single-chain fv fragments in plants using a potato virus x episomal vector. | we have used a plant virus episomal vector, based on potato virus x (pvx) to transiently express a single-chain fv (scfv) and its diabody derivative in plants. the scfv was directed against a continuous epitope (cryptotope) on the coat protein of potato virus v. a cloned, full-length pvx vector sequence, containing the scfv gene, was used to direct in vitro transcription and the resulting rna was used to inoculate nicotiana clevelandii plants. within a few days, plants developed characteristic s ... | 1999 | 10648933 |
| identification of a pathogenicity determinant of plum pox virus in the sequence encoding the c-terminal region of protein p3+6k(1). | a full-length genomic cdna clone of a plum pox potyvirus (ppv) isolate belonging to the m strain (ppv-ps) has been cloned downstream from a bacteriophage t7 polymerase promoter and sequenced. transcripts from the resulting plasmid, pgppvps, were infectious and, in herbaceous hosts, produced symptoms that differed from those of virus progeny of pgppv, a full-length genomic cdna clone of the d strain ppv-r. viable ppv-r/-ps chimeric viruses were constructed by recombination of the cdna clones in v ... | 2000 | 10675393 |
| preservation of 5'-end integrity of a potyvirus genomic rna is not dependent on template specificity. | full-length in vitro transcripts of plum pox potyvirus (ppv) genomic rna with mutations altering the number of 5'-terminal adenosine residues were able to infect nicotiana clevelandii plants, whereas a mutant with a substitution of adenosine in position 2 by guanosine failed to infect. the genomic 5' end was template-independently repaired during in vivo rna synthesis producing wild-type viral progeny. putative models of replication initiation are discussed. | 2000 | 10753716 |
| episomal expression of a hammerhead ribozyme directed against plum pox virus. | two related antisense rnas directed against plum pox virus (ppv) were expressed episomally in nicotiana clevelandii by infection with recombinant potato virus x (pvx). one recombinant pvx expressed an ordinary ppv antisense rna of about 400 nucleotides, while the other expressed a related antisense rna that carried the catalytic domain of a hammerhead ribozyme. inoculation with the latter recombinant pvx resulted in the accumulation of ribozyme rna that was catalytically active when tested in vi ... | 2000 | 10930659 |
| the complete nucleotide sequence and synthesis of infectious rna of genomic and defective interfering rnas of tbsv-p. | the complete nucleotide sequences of the genome of the pepper isolate of tomato bushy stunt tombusvirus (tbsv-p), and its defective interfering (di) rnas were determined. the genome of tbsv-p is a linear single-stranded monopartite rna molecule of positive polarity, 4776 nucleotides long and has an organisation identical to that reported for other tombusviruses. in vitro transcripts of the genome were highly infectious, and it could support replication of the di rnas associated with the wild typ ... | 2000 | 11018282 |
| mechanical transmission of poleroviruses. | previously, transmission of poleroviruses has relied solely on the use of their aphid vectors. biolistic inoculation allowed for the first time the mechanical transmission of beet western yellows virus (bwyv) and potato leafroll virus (plrv) to several host plants. inoculation with purified preparations and viral rna extracts of plrv resulted in 30-50% systemically infected nicotiana occidentalis p1 plants and 15-30% infected nicotiana clevelandii plants. particle bombardment was also used succe ... | 2001 | 11164501 |
| non-targeted and targeted protein movement through plasmodesmata in leaves in different developmental and physiological states. | plant cells rely on plasmodesmata for intercellular transport of small signaling molecules as well as larger informational macromolecules such as proteins. a green fluorescent protein (gfp) reporter and low-pressure microprojectile bombardment were used to quantify the degree of symplastic continuity between cells of the leaf at different developmental stages and under different growth conditions. plasmodesmata were observed to be closed to the transport of gfp or dilated to allow the traffic of ... | 2001 | 11299360 |
| type iii secretion in plant growth-promoting pseudomonas fluorescens sbw25. | in vivo expression technology (ivet) analysis of rhizosphere-induced genes in the plant growth-promoting rhizobacterium (pgpr) pseudomonas fluorescens sbw25 identified a homologue of the type iii secretion system (ttss) gene hrcc. the hrcc homologue resides within a 20-kb gene cluster that resembles the type iii (hrp) gene cluster of pseudomonas syringae. the type iii (rsp) gene cluster in p. fluorescens sbw25 is flanked by a homologue of the p. syringae ttss-secreted protein avre. p. fluorescen ... | 2001 | 11555282 |
| heca, a member of a class of adhesins produced by diverse pathogenic bacteria, contributes to the attachment, aggregation, epidermal cell killing, and virulence phenotypes of erwinia chrysanthemi ec16 on nicotiana clevelandii seedlings. | erwinia chrysanthemi is representative of a broad class of bacterial pathogens that are capable of inducing necrosis in plants. the e. chrysanthemi ec16 heca gene predicts a 3,850-aa member of the bordetella pertussis filamentous hemagglutinin family of adhesins. a hecatn7 mutant was reduced in virulence on nicotiana clevelandii seedlings after inoculation without wounding. epifluorescence and confocal laser-scanning microscopy observations of heca and wild-type cells expressing the green fluore ... | 2002 | 12271135 |
| increase in plasmodesmatal permeability during cell-to-cell spread of tobacco rattle virus from individually inoculated cells. | a microinjection technique was devised for inoculation of single nicotiana clevelandii leaf trichome cells with virus particles. by removing inoculated trichomes at various times after microinjection, it was shown that at least 4 hr were required for tobacco rattle virus (trv; tobravirus group) to move out of primarily inoculated cells. effects of the early stages of trv infection on plasmodesmatal permeability were examined by microinjection of fluorochrome-labeled molecules. fluorescein-labele ... | 1992 | 12297638 |
| limited utility of blue fluorescent protein (bfp) in monitoring plant virus movement. | while the green fluorescent protein (gfp) is a routinely used marker gene in higher plants, there are only a few data concerning the use of blue fluorescent protein (bfp). these proteins together are used for dual colour tagging experiments in various biological systems; however, the benefits of this technique in plant virology have not been exploited yet. in this work, our aim was to determine whether the bfp is a suitable second marker in conjunction with gfp for following the progress of viru ... | 2002 | 12504279 |
| effects of point mutations in the major capsid protein of beet western yellows virus on capsid formation, virus accumulation, and aphid transmission. | point mutations were introduced into the major capsid protein (p3) of cloned infectious cdna of the polerovirus beet western yellows virus (bwyv) by manipulation of cloned infectious cdna. seven mutations targeted sites on the s domain predicted to lie on the capsid surface. an eighth mutation eliminated two arginine residues in the r domain, which is thought to extend into the capsid interior. the effects of the mutations on virus capsid formation, virus accumulation in protoplasts and plants, ... | 2003 | 12584348 |
| characterization of a distinct carlavirus isolated from verbena. | avirus was isolated from verbena plants that bore virus-like symptoms. the virus, for which the name verbena latent virus (velv) is proposed, was consistently isolated from these plants, both with and without disease symptoms. electron microscopy studies of ultrathin sections of infected verbena tissues revealed the presence of elongated flexuous virus particles, ca. 650 nm in length. its experimental host range was limited to verbena spp. and nicotiana clevelandii. no inclusion bodies or specif ... | 2003 | 12721806 |
| manduca sexta recognition and resistance among allopolyploid nicotiana host plants. | allopolyploid speciation occurs instantly when the genomes of different species combine to produce self-fertile offspring and has played a central role in the evolution of higher plants, but its consequences for adaptive responses are unknown. we compare herbivore-recognition and -resistance responses of the diploid species and putative ancestral parent nicotiana attenuata with those of the two derived allopolyploid species nicotiana clevelandii and nicotiana bigelovii. manduca sexta larvae atta ... | 2003 | 14530394 |
| host responses to transient expression of individual genes encoded by tomato leaf curl virus. | the six open reading frames of tomato leaf curl virus (tlcv) were expressed in host nicotiana species using a tobacco mosaic virus vector. each of the genes, except that encoding the viral coat protein, produced a phenotypic effect when expressed in planta, but the corresponding untranslatable mutant genes were asymptomatic. the c1 (rep) gene invoked a hypersensitive response in nicotiana clevelandii that restricted the viral construct to sites of infection. expression of the c2 gene in n. benth ... | 2004 | 14714865 |
| consistency of nicotiana attenuata's herbivore- and jasmonate-induced transcriptional responses in the allotetraploid species nicotiana quadrivalvis and nicotiana clevelandii. | we examined the consistency of the native diploid nicotiana attenuata (na)'s herbivore-induced transcriptional changes in the two allotetraploid natives, nicotiana clevelandii (nc) and nicotiana quadrivalvis (nq), which are thought to be derived from hybridizations with an ancestral na. an analysis of nuclear-encoded chloroplast-expressed gln synthetase gene (ncpgs) sequences found strong similarity between nc and na and between n. trigonophylla and the two allopolyploids. all species were elici ... | 2004 | 15133150 |
| the erwinia chrysanthemi ec16 hrp/hrc gene cluster encodes an active hrp type iii secretion system that is flanked by virulence genes functionally unrelated to the hrp system. | erwinia chrysanthemi is a host-promiscuous plant pathogen that possesses a type iii secretion system (ttss) similar to that of the host-specific pathogens e. amylovora and pseudomonas syringae. the regions flanking the ttss-encoding hrp/hrc gene clusters in the latter pathogens encode various ttss-secreted proteins. dna sequencing of the complete e. chrysanthemi hrp/hrc gene cluster and approximately 12 kb of the flanking regions (beyond the previously characterized heca adhesin gene in the left ... | 2004 | 15195947 |
| the necrotic pathotype of the cucumber mosaic virus (cmv) ns strain is solely determined by amino acid 461 of the 1a protein. | the unique ns isolate of cucumber mosaic virus (cmv) induces necrotic lesions on several nicotiana spp. in contrast to other strains that cause systemic mosaic on these plants. by using biologically active rna transcripts from cdnas of ns-cmv and a reference subgroup i strain rs-cmv, we confined the genetic determinant solely responsible for necrosis induction to amino acid 461 of the la protein translated from genomic rna1. an arg to cys change at this position (r461c) rendered rs-cmv necrotic, ... | 2004 | 15305604 |
| potato virus x tgbp1 induces plasmodesmata gating and moves between cells in several host species whereas cp moves only in n. benthamiana leaves. | experiments were conducted to compare the plasmodesmal transport activities of potato virus x (pvx) tgbp1 and coat protein (cp) in several plant species. microinjection experiments indicated that tgbp1 gates plasmodesmata in nicotiana tabacum leaves. these results support previous microinjection studies indicating that tgbp1 gates plasmodesmata in nicotiana benthamiana and nicotiana clevelandii leaves. to study protein movement, plasmids expressing the green fluorescent protein (gfp) gene fused ... | 2004 | 15464839 |
| mimicking carboxyterminal phosphorylation differentially effects subcellular distribution and cell-to-cell movement of tobacco mosaic virus movement protein. | phosphorylation of tobacco mosaic virus movement protein (tmv-mp) at three carboxyterminal ser/thr sites negatively regulates tmv-mp gating function and viral spread in nicotiana tabacum but not in nicotiana benthamiana, indicating a host dependant inactivation strategy. here, we examine the effect of mimicking carboxyterminal phosphorylation on cell-to-cell transport of tmv-mp protein itself in host plants nicotiana clevelandii, n. benthamiana, nicotiana glutinosa and n. tabacum. since tmv-mp t ... | 2005 | 15680421 |
| the lettuce infectious yellows virus (liyv)-encoded p26 is associated with plasmalemma deposits within liyv-infected cells. | cytological, immunological, and mutagenesis approaches were used to identify the viral factors associated with the formation of plasmalemma deposits (plds) in whole plants and protoplasts infected by lettuce infectious yellows virus (liyv). transmission electron microscopy and immunogold labeling using polyclonal antibodies to four of the five liyv rna 2-encoded large proteins, capsid protein (cp), minor capsid protein (cpm), hsp70 homolog (hsp70h), and p59, showed specific labeling of liyv viri ... | 2005 | 15721368 |
| characterization of potato virus y (pvy) molecular determinants involved in the vein necrosis symptom induced by pvyn isolates in infected nicotiana tabacum cv. xanthi. | viral molecular determinant(s) involved in the tobacco vein necrosis (tvn) symptom induced by necrotic isolates of potato virus y (pvy) on nicotiana tabacum cv. xanthi leaves remain undetermined. reference isolates belonging to pvy(n) (infectious pvy(n)-605 clone) and pvy(o) (pvy(o)-139) were used to produce pvy chimeric genomes by using reverse-genetic techniques. these chimeric clones were inoculated biolistically onto nicotiana clevelandii plants to establish the clone, prior to being tested ... | 2005 | 15958688 |
| identification of secret agent as the o-glcnac transferase that participates in plum pox virus infection. | serine and threonine of many nuclear and cytoplasmic proteins are posttranslationally modified with o-linked n-acetylglucosamine (o-glcnac). this modification is made by o-linked n-acetylglucosamine transferases (ogts). genetic and biochemical data have demonstrated the existence of two ogts of arabidopsis thaliana, secret agent (sec) and spindly (spy), with at least partly overlapping functions, but there is little information on their target proteins. the n terminus of the capsid protein (cp) ... | 2005 | 16014901 |
| model plants for studying the interaction between methylobacterium mesophilicum and xylella fastidiosa. | over the last few years, endophytic bacterial communities associated with citrus have been studied as key components interacting with xylella fastidiosa. in this study, we investigated the possible interaction between the citrus endophyte methylobacterium mesophilicum sr1.6/6 and x. fastidiosa in model plants such as catharanthus roseus (madagaskar periwinkle) and nicotiana clevelandii (clevelands tobacco). the aim of this study was to establish the fate of m. mesophilicum sr1.6/6 after inoculat ... | 2006 | 16699566 |
| mapping of two o-glcnac modification sites in the capsid protein of the potyvirus plum pox virus. | a large number of o-linked n-acetylglucosamine (o-glcnac) residues have been mapped in vertebrate proteins, however targets of o-glcnacylation in plants still have not been characterized. we show here that o-glcnacylation of the n-terminal region of the capsid protein of plum pox virus resembles that of animal proteins in introducing o-glcnac monomers. thr-19 and thr-24 were specifically o-glcnacylated. these residues are surrounded by amino acids typical of animal o-glcnac acceptor sites, sugge ... | 2006 | 17014851 |
| an antibody derivative expressed from viral vectors passively immunizes pigs against transmissible gastroenteritis virus infection when supplied orally in crude plant extracts. | to investigate the potential of antibody derivatives to provide passive protection against enteric infections when supplied orally in crude plant extracts, we have expressed a small immune protein (sip) in plants using two different plant virus vectors based on potato virus x (pvx) and cowpea mosaic virus (cpmv). the epsilonsip molecule consisted of a single-chain antibody (scfv) specific for the porcine coronavirus transmissible gastroenteritis virus (tgev) linked to the epsilon-ch4 domain from ... | 2006 | 17309733 |
| evaluation of endophytic colonization of citrus sinensis and catharanthus roseus seedlings by endophytic bacteria. | over the last few years, the endophytic bacterial community associated with citrus has been studied as an important component interacting with xylella fastidiosa, the causal agent of citrus variegated chlorosis (cvc). this bacterium may also colonize some model plants, such as catharanthus roseus and nicotiana clevelandii. in the present study, we compared the endophytic colonization of citrus sinensis and catharanthus roseus using the endophytic bacteria klebsiella pneumoniae. we chose an appro ... | 2007 | 17342049 |
| recovery of nicotiana benthamiana plants from a necrotic response induced by a nepovirus is associated with rna silencing but not with reduced virus titer. | recovery of plants from virus-induced symptoms is often described as a consequence of rna silencing, an antiviral defense mechanism. for example, recovery of nicotiana clevelandii from a nepovirus (tomato black ring virus) is associated with a decreased viral rna concentration and sequence-specific resistance to further virus infection. in this study, we have characterized the interaction of another nepovirus, tomato ringspot virus (torsv), with host defense responses during symptom induction an ... | 2007 | 17728227 |
| identification of plum pox virus pathogenicity determinants in herbaceous and woody hosts. | plum pox virus (ppv) is a member of the genus potyvirus that is able to infect a large variety of plant species, including trees of the genus prunus, its natural host. when some ppv isolates are propagated for an extended time in herbaceous plants, their ability to infect trees is reduced. the molecular basis of this change in host infectivity is poorly understood. we report the construction of hybrid viruses from cdna clones of two d-strain isolates of ppv, ppv-d and ppv-r, which differ in thei ... | 2008 | 18052879 |
| biological activity of transcripts from cdna of pelargonium line pattern virus. | a set of cdnas of pelargonium line pattern virus (plpv) was assembled under the control of t7 rna polymerase promoter and ligated into the plasmid puc18. transcripts synthesized in vitro from cdna were infectious on chenopodium quinoa according to locally induced lesions and hybridization assay. the biological activity of the viral transcripts was particularly sensitive to the short 3' terminus extensions, whereas inclusion of the 3 extra bases at the 5' terminus did not substantially affect the ... | 2007 | 18197735 |
| studies on encapsidated viroid-like rna. iv. requirement for infectivity and specificity of two rna components from velvet tobacco mottle virus. | neither the virus-like rna (rna 1) nor the viroid-like rna (rna 2) of velvet tobacco mottle virus (vtmov) is capable of independent replication in nicotiana clevelandii. the function of rna 2 for the rna 1 replication could not be fulfilled by conventional viroids such as those of chrysanthemum stunt, citrus exocortis, or the viroid-like rnas associated with avocado sunblotch and cadang-cadang disease of coconut. similarly, rna 2 failed to replicate when coinoculated with rnas of conventional vi ... | 1981 | 18635049 |
| detection, isolation, and characterization of high molecular weight double-stranded rnas in plants infected with velvet tobacco mottle virus. | two species of double-stranded (ds) rna were detected in nicotiana clevelandii infected with velvet tobacco mottle virus (vtmov) which were not present in healthy plants. the ds-rnas were first detected by polyacrylamide gel electrophoresis 2 to 4 and about 8 days after inoculation in the inoculated and systemically infected leaves respectively. thereafter the concentrations of ds-rna increased significantly. the vtmov-specific ds-rna was purified from plants 10 to 14 days after inoculation. the ... | 1983 | 18638973 |
| subgenomic rnas with nucleotide sequences derived from rnas 1 and 2 of cucumber mosaic virus can act as messenger rnas in vitro. | encapsidated rnas of cucumber mosaic virus (cmv) were analyzed by hybridization to specific probes after gel electrophoresis. [32p]-complementary dna (cdna) probes were prepared by transcription of genomic rna 1 and rna 2 nucleotide sequences that had been cloned in a bacteriophage m13 vector. probes that correspond to unique sequences near the 3' ends of rna 1 and rna 2 revealed over 20 smaller rnas. the subgenomic rnas derived from each genomic rna were analyzed more definitively by hybrid sel ... | 1985 | 18639845 |
| isolation of velvet tobacco mottle virus capable of replication with and without a viroid-like rna. | field isolates of velvet tobacco mottle virus (vtmov) induce severe symptoms in nicotiana clevelandii and encapsidate viroid-like rna reported to be essential for virus infection. an isolate of the virus producing only mild symptoms on n. clevelandii and devoid of viroid-like rna has now been isolated from a plant inoculated by a single viruliferous cyrtopeltis nicotianae, the mirid vector. however, after adding viroid-like rna isolated from normal vtmov to the inoculum, the new isolate was show ... | 1986 | 18640583 |
| the in vitro synthesis of velvet tobacco mottle virus-specific double-stranded rna by a soluble fraction in extracts from infected nicotiana clevelandii leaves. | rna-dependent rna polymerase activity was detected in a membrane-free cytoplasmic fraction from the leaves of nicotiana clevelandii 4 days after inoculation with velvet tobacco mottle virus (vtmov). the amount of enzyme activity was still increasing 8 days after inoculation when virus-induced local lesions were becoming necrotic. rna synthesis in extracts from leaves infected for 7 days proceeded linearly for about 10 min and required all four ribonucleoside triphosphates and magnesium ions. enz ... | 1986 | 18640654 |
| in vivo encapsidation of potato spindle tuber viroid by velvet tobacco mottle virus particles. | when nicotiana clevelandii was inoculated simultaneously with velvet tobacco mottle virus (vtmov) and potato spindle tuber viroid (pstv), replication of the viroid was greatly suppressed. however, both pathogens replicated if pstv was inoculated several days before the vtmov. small amounts of pstv were detected by dot-blot analysis of rna in highly purified vtmov isolated from coinfected plants indicating that the viroid had been encapsidated by the virus particles. moreover, tomato plants which ... | 1986 | 18640657 |
| host-specific effect of p1 exchange between two potyviruses. | the potyviruses plum pox virus (ppv) and tobacco vein mottling virus (tvmv) have distinct host ranges and induce different symptoms in their common herbaceous hosts. to test the relevance of the p1 protein in host compatibility and pathogenicity, hybrid viruses were constructed in which the p1 coding sequence of ppv was completely or partially replaced by the corresponding sequences from tvmv. infections induced by these chimeric viruses revealed that the tvmv p1 and a ppv/tvmv hybrid p1 protein ... | 2008 | 18705848 |
| biological and molecular characterization of a new carlavirus isolated from an aconitum sp. | abstract a new virus was isolated from symptomless aconitum napellus plants. the virus, for which the name aconitum latent virus (aclv) is proposed, has flexuous particles 640 nm in length. the experimental host range was limited to nicotiana clevelandii. electron microscopy studies of ultrathin sections of infected a. napellus tissues revealed the presence of elongated virus particles. no inclusion bodies characteristic of potyvirus infection were observed. aclv was purified from naturally infe ... | 2000 | 18944582 |
| tomato chlorosis virus: a new whitefly-transmitted, phloem-limited, bipartite closterovirus of tomato. | abstract tomato chlorosis virus (tocv) is the second whitefly-transmitted, phloem-limited, bipartite closterovirus described infecting tomato. tocv is distinct from tomato infectious chlorosis virus (ticv), based on lack of serological and nucleic acid cross-reactions and differences in vector specificity. ticv is transmitted only by the greenhouse whitefly (trialeurodes vaporariorum), whereas tocv is transmitted by the greenhouse whitefly, the banded-wing whitefly (t. abutilonea), and bemisia t ... | 1998 | 18944918 |
| the acquisition of molecular determinants involved in potato virus y necrosis capacity leads to fitness reduction in tobacco plants. | the prevalence of necrotic potato virus y (pvy) in natural populations could reflect increased fitness of necrotic isolates. in this paper, the effects of the acquisition of molecular determinants (a/g(2213) and a/c(2271)) involved in necrosis capacity on both the number of progeny produced and the competitiveness of pvy were characterized. the relationship between necrosis and fitness was tested using (i) nicotiana tabacum cv. xanthi and nicotiana clevelandii, (ii) necrotic pvy(n)-605 and non-n ... | 2009 | 19088295 |
| tobacco streak virus isolated from lettuce. | tobacco streak virus (tsv) is an ilarvirus with a worldwide distribution. this virus infects many plants and causes significant yield losses. in this study, 300 samples of lettuce were collected from lettuce fields in tehran province. infected plants show symptoms such as: mosaic, vein clearing, vein necrosis, yellowing and leaf distortion. das-elisa (double antibody sandwich-elisa) was used with a polyclonal antiserum against tsv. five isolates (t1, t2, t3, t4 and t5), which are collected, resp ... | 2009 | 19634475 |
| capsid protein of cowpea chlorotic mottle virus is a determinant for vector transmission by a beetle. | cowpea chlorotic mottle virus (ccmv) is a bromovirus transmitted by species of chrysomelid beetles, including the spotted cucumber beetle, diabrotica undecimpunctata howardii barber. an experimental system was set up to identify the viral determinant(s) of the beetle transmission of ccmv. nicotiana clevelandii was selected as an experimental plant host because it supports the replication and accumulation of both ccmv and a second member of the family bromoviridae, cucumber mosaic virus (cmv). us ... | 2010 | 19828763 |
| identification a coat protein region of cucumber mosaic virus (cmv) essential for long-distance movement in cucumber. | to characterise the long-distance movement determinant of cucumoviral coat proteins (cps), five mutants were engineered into the cmv cp bearing the corresponding tomato aspermy virus (tav) loops exposed on the surface of the virion. both viruses can move long-distance in nicotiana clevelandii, but only cmv can move long-distance in cucumber. investigation of the cmv chimeras identified three amino acids of the βb-βc loop that were essential for the cmv long-distance movement in cucumber. introdu ... | 2011 | 21927896 |
| the n-terminal 12 amino acids of tomato aspermy virus 2b protein function in infection and recombination. | the roles for various regions of the 2b protein in infection, hypervirulence and recombination were examined by introducing stop codons in a chimeric virus containing rna 1 from the cucumber mosaic virus (cmv strain q), rna 3 from the tomato aspermy virus (tav) and rna 2 of cmv with a 2b gene from tav. chimeric virus expressing the intact 2b protein induced severe symptoms in inoculated nicotiana clevelandii and nicotiana glutinosa and facilitated cmv-tav recombination, while chimeric viruses no ... | 2011 | 21880843 |
| coat protein mediated resistance to plum pox virus in nicotiana clevelandii and n. benthamiana. | transgenic nicotiana benthamiana and n. clevelandii plants expressing the coat protein of plum pox virus under the control of the 35s promoter from cauliflower mosaic virus were engineered by agrobacterium tumefaciens mediated transformation. the phenomenon of virus resistance was observed at different levels when transgenic plants, expressing the coat protein and control plants were compared after challenge infection with plum pox virus. n. clevelandii coat protein transgenic plants circumvent ... | 1992 | 24213033 |
| a symptom variant of beet curly top geminivirus produced by mutation of open reading frame c4. | two beet curly top virus (bctv) mutants have been constructed in vitro that contain g-to-t transversions either at nucleotide 2682 or at nucleotide 2802 within the overlapping open reading frames (orfs) c1 and c4. the mutations introduce termination codons in orf c4 without affecting the amino acids encoded by orf c1. when agroinoculated into nicotiana benthamiana the mutants caused stunting and yellowing of the plant and downward leaf curl but not the vein swelling and upward leaf curl symptoms ... | 1992 | 1529551 |
| effect of virus infection on symplastic transport of fluorescent tracers in nicotiana clevelandii leaf epidermis. | the molecular weight exclusion limit of plasmodesmata in subveinal epidermal cells of nicotiana clevelandii (gray) leaves was estimated by microinjection and fluorescence microscopy using fluorescein isothiocyanate-peptide conjugates, carboxyfluorescein and lucifer yellow ch. the largest fluorochrome which moved symplastically between cells had a molecular weight of 749, although movement did not appear to depend purely on molecular weight parameters. systemic infection of plants by tobacco ratt ... | 1990 | 24196937 |
| visual monitoring of cucumber mosaic virus infection in nicotiana benthamiana following transmission by the aphid vector myzus persicae. | the single-stranded, positive-sense and tripartite rna virus cucumber mosaic virus (cmv) was used in this study as a method for monitoring the initial stages of virus infection following aphid transmission. the rna2 of cmv was modified to incorporate, in a variety of arrangements, an open reading frame (orf) encoding an enhanced green fluorescent protein (egfp). the phenotypes of five engineered rna2s were tested in nicotiana tabacum, nicotiana clevelandii and nicotiana benthamiana. only one con ... | 2015 | 25979730 |
| nucleotide sequence, genomic organization and synthesis of infectious transcripts from a full-length clone of artichoke mottle crinkle virus. | the complete nucleotide sequence of the genome of artichoke mottle crinkle virus (amcv), a member of the tombusvirus group, has been determined. the genome is 4790 nucleotides (nt) in length. a full-length cdna of the amcv genome has been cloned in puc9 downstream of the t7 rna polymerase promoter. transcripts were infective when inoculated onto nicotiana clevelandii and n. benthamiana plants. the amcv genome contains five open reading frames (orfs). the first orf from the 5' terminus (orf1) enc ... | 1994 | 8021582 |
| a strain-specific segment of the rna-dependent rna polymerase of grapevine fanleaf virus determines symptoms in nicotiana species. | factors involved in symptom expression of viruses from the genus nepovirus in the family secoviridae such as grapevine fanleaf virus (gflv) are poorly characterized. to identify symptom determinants encoded by gflv, infectious cdna clones of rna1 and rna2 of strain ghu were developed and used alongside existing infectious cdna clones of strain f13 in a reverse genetics approach. in vitro transcripts of homologous combinations of rna1 and rna2 induced systemic infection in nicotiana benthamiana a ... | 2013 | 24088345 |
| is hammerhead self-cleavage involved in the replication of a virusoid in vivo? | the hammerhead self-cleavage reaction is generally considered to be involved in the in vivo production of (+) and (-) monomeric rnas of the viroid-like, satellite rna or virusoid of lucerne transient streak virus (vltsv) from multimeric replicative intermediates, as part of the symmetrical rolling circle mechanism. to test this, three cdna clones of vltsv rna, mutated at sites that inactivate in vitro self-cleavage of (-) rna, were inoculated as excised plasmid cdna inserts, together with helper ... | 1993 | 7684871 |
| diverse amino acid changes at specific positions in the n-terminal region of the coat protein allow plum pox virus to adapt to new hosts. | plum pox virus (ppv)-d and ppv-r are two isolates from strain d of ppv that differ in host specificity. previous analyses of chimeras originating from ppv-r and ppv-d suggested that the n terminus of the coat protein (cp) includes host-specific pathogenicity determinants. here, these determinants were mapped precisely by analyzing the infectivity in herbaceous and woody species of chimeras containing a fragment of the 3' region of ppv-d (including the region coding for the cp) in a ppv-r backbon ... | 2013 | 23745677 |