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Jean Dunez - One of the best experts on this subject based on the ideXlab platform.
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Characterization of a New Nepovirus Infecting Apricot in Southeastern France: Apricot Latent Ringspot Virus
European Journal of Plant Pathology, 2001Co-Authors: Pascal Gentit, Thierry Candresse, René-pierre Delbos, Jean DunezAbstract:A pathogen was transmitted from apricot trees showing symptoms of viral infection to GF305 peach seedlings which reacted by stunting, shortened internodes and chlorotic mottling. The agent was transmitted to cherry, apricot, peach and plum by grafting and to several herbaceous hosts by mechanical inoculation. Isometric Nepovirus-like particles of 30–31 nm diameter extracted from infected Chenopodium quinoa sedimented as two peaks in sucrose gradients. These particles contained two single stranded RNAs of approximately 5.9 and 7.9 kb, and a single coat protein subunit of 53.7 kDa. No cross-reactions were observed with a number of Nepoviruses infecting fruit trees. Inoculation of purified particles to herbaceous or woody hosts reproduced the same symptoms caused by the original isolate. Sequencing of a 2.2 kbp cDNA clone covering the 3′ end of the small genomic RNA identified an open reading frame encoding a 317 aa N-truncated protein exhibiting significant similarities with the coat protein of Nepoviruses. The 1257 nt long 3′ non-coding region showed up to about 65% homology to the equivalent region of members of the subgroup C of Nepoviruses. The properties of this pathogen do not match those of any previously described Nepovirus. It should therefore be considered as a new member of the subgroup C of Nepoviruses, for which the name of Apricot latent ringspot virus (ALRSV) is proposed. The nucleotide sequence reported in this work has been deposited in the EMBL databank under the accession number AJ278875.
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An RNA-dependent-RNA-polymerase activity associated with grapevine chrome mosaic Nepovirus infection
Archives of Virology, 1997Co-Authors: Olivier Gall, Thierry Candresse, Jean DunezAbstract:A virus-induced, viral RNA-specific, RNA-dependent-RNA-poly-merase activity has been observed in vitro associated with membrane extracts of plants of three different species after infection with grapevine chrome mosaic Nepovirus (GCMV). The products of this activity are full-length, positive sense GCMV RNAs present in double-stranded structures. As has been demonstrated for a relative to Nepoviruses, cowpea mosaic comovirus, this activity probably corresponds to the nepoviral replication complex.
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the nucleotide sequence of the rna 2 of an isolate of the english serotype of tomato black ring virus rna recombination in the history of Nepoviruses
Journal of General Virology, 1995Co-Authors: Le O Gall, Maryvonne Lanneau, Thierry Candresse, Jean DunezAbstract:The RNA-2 of a carrot isolate from the English serotype of tomato black ring Nepovirus (TBRV-ED) has been sequenced. It is 4618 nucleotides long and contains one open reading frame encoding a polypeptide of 1344 amino acids. The 5′ non-coding region contains three repetitions of a stem-loop structure also conserved in TBRV-Scottish and grapevine chrome mosaic Nepovirus (GCMV). The coat protein domain was mapped to the carboxy-terminal one-third of the polyprotein. Sequence comparisons indicate that TBRV-ED RNA-2 probably arose by an RNA recombination event that resulted in the exchange of the putative movement protein gene between TBRV and GCMV.
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Genetically engineered resistance against grapevine chrome mosaic Nepovirus
Plant Molecular Biology, 1993Co-Authors: Veronique Brault, Olivier Gall, Thierry Candresse, René Pierre Delbos, Maryvonne Lanneau, Jean DunezAbstract:Nepoviruses are a group of isometric plant viruses with a genome divided between two-single-stranded, positive-sense, RNA molecules. They are usually transmitted by nematodes and a number of them have significant economic impact, especially in perennial crops such as grapevine and fruit trees. Like all other picorna-like viruses, Nepoviruses express their coat protein (CP) as part of a larger polyprotein which is further processed by a virus-encoded protease, a feature which poses specific problems when trying to express the viral coat protein in transgenic plants. A hybrid gene, driving the high-level expression of the CP of grapevine chrome mosaic Nepovirus (GCMV) has been constructed and transferred to the genome of tobacco plants. Progeny of CP-expressing transformants show resistance against GCMV. When compared to control plants, fewer inoculated plants become infected and those that become infected accumulate reduced levels of viral RNAs. This protection was also shown to be efficient when plants are inoculated with purified viral RNA.
Thierry Candresse - One of the best experts on this subject based on the ideXlab platform.
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first report of nasturtium as a natural host of cherry leaf roll virus on amsterdam island
Plant Disease, 2010Co-Authors: Armelle Marais, Thierry Candresse, Chantal Faure, M HulleAbstract:Cherry leaf roll virus (CLRV) is a well-known virus belonging to the genus Nepovirus, but unlike most members of this genus, it is not known to be transmitted by nematodes but only through seeds and pollen. Since its first description in 1955 on Prunus avium L. in England (1), CLRV has been shown to have a worldwide distribution and a wide natural host range. During a survey of plant viruses in the French sub-Antarctic islands, samples from nasturtium plants (Tropaeolum majus), an introduced plant species, showing symptoms of leaf mosaic, deformation, and veinal necrosis were collected on Amsterdam Island. Upon mechanical transmission with sap extracts, necrotic ringspot and oak-leaf symptoms typical of Nepovirus infection were observed on the leaves of inoculated Nicotiana clevelandii and N. tabacum plants. Inoculation of healthy nasturtium plants resulted in mosaic and pin-point necrosis symptoms. Electron microscopy on negatively stained sap extracts revealed the presence of icosahedral virions, 28 to ...
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Characterization of a New Nepovirus Infecting Apricot in Southeastern France: Apricot Latent Ringspot Virus
European Journal of Plant Pathology, 2001Co-Authors: Pascal Gentit, Thierry Candresse, René-pierre Delbos, Jean DunezAbstract:A pathogen was transmitted from apricot trees showing symptoms of viral infection to GF305 peach seedlings which reacted by stunting, shortened internodes and chlorotic mottling. The agent was transmitted to cherry, apricot, peach and plum by grafting and to several herbaceous hosts by mechanical inoculation. Isometric Nepovirus-like particles of 30–31 nm diameter extracted from infected Chenopodium quinoa sedimented as two peaks in sucrose gradients. These particles contained two single stranded RNAs of approximately 5.9 and 7.9 kb, and a single coat protein subunit of 53.7 kDa. No cross-reactions were observed with a number of Nepoviruses infecting fruit trees. Inoculation of purified particles to herbaceous or woody hosts reproduced the same symptoms caused by the original isolate. Sequencing of a 2.2 kbp cDNA clone covering the 3′ end of the small genomic RNA identified an open reading frame encoding a 317 aa N-truncated protein exhibiting significant similarities with the coat protein of Nepoviruses. The 1257 nt long 3′ non-coding region showed up to about 65% homology to the equivalent region of members of the subgroup C of Nepoviruses. The properties of this pathogen do not match those of any previously described Nepovirus. It should therefore be considered as a new member of the subgroup C of Nepoviruses, for which the name of Apricot latent ringspot virus (ALRSV) is proposed. The nucleotide sequence reported in this work has been deposited in the EMBL databank under the accession number AJ278875.
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An RNA-dependent-RNA-polymerase activity associated with grapevine chrome mosaic Nepovirus infection
Archives of Virology, 1997Co-Authors: Olivier Gall, Thierry Candresse, Jean DunezAbstract:A virus-induced, viral RNA-specific, RNA-dependent-RNA-poly-merase activity has been observed in vitro associated with membrane extracts of plants of three different species after infection with grapevine chrome mosaic Nepovirus (GCMV). The products of this activity are full-length, positive sense GCMV RNAs present in double-stranded structures. As has been demonstrated for a relative to Nepoviruses, cowpea mosaic comovirus, this activity probably corresponds to the nepoviral replication complex.
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the nucleotide sequence of the rna 2 of an isolate of the english serotype of tomato black ring virus rna recombination in the history of Nepoviruses
Journal of General Virology, 1995Co-Authors: Le O Gall, Maryvonne Lanneau, Thierry Candresse, Jean DunezAbstract:The RNA-2 of a carrot isolate from the English serotype of tomato black ring Nepovirus (TBRV-ED) has been sequenced. It is 4618 nucleotides long and contains one open reading frame encoding a polypeptide of 1344 amino acids. The 5′ non-coding region contains three repetitions of a stem-loop structure also conserved in TBRV-Scottish and grapevine chrome mosaic Nepovirus (GCMV). The coat protein domain was mapped to the carboxy-terminal one-third of the polyprotein. Sequence comparisons indicate that TBRV-ED RNA-2 probably arose by an RNA recombination event that resulted in the exchange of the putative movement protein gene between TBRV and GCMV.
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Genetically engineered resistance against grapevine chrome mosaic Nepovirus
Plant Molecular Biology, 1993Co-Authors: Veronique Brault, Olivier Gall, Thierry Candresse, René Pierre Delbos, Maryvonne Lanneau, Jean DunezAbstract:Nepoviruses are a group of isometric plant viruses with a genome divided between two-single-stranded, positive-sense, RNA molecules. They are usually transmitted by nematodes and a number of them have significant economic impact, especially in perennial crops such as grapevine and fruit trees. Like all other picorna-like viruses, Nepoviruses express their coat protein (CP) as part of a larger polyprotein which is further processed by a virus-encoded protease, a feature which poses specific problems when trying to express the viral coat protein in transgenic plants. A hybrid gene, driving the high-level expression of the CP of grapevine chrome mosaic Nepovirus (GCMV) has been constructed and transferred to the genome of tobacco plants. Progeny of CP-expressing transformants show resistance against GCMV. When compared to control plants, fewer inoculated plants become infected and those that become infected accumulate reduced levels of viral RNAs. This protection was also shown to be efficient when plants are inoculated with purified viral RNA.
J. I. Cooper - One of the best experts on this subject based on the ideXlab platform.
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The nucleotide sequence of a satellite RNA associated with strawberry latent ringspot virus
2013Co-Authors: S. Kreiah, J. I. Cooper, G. StrunkAbstract:The nucleotide sequence of a satellite RNA associated with a strawberry isolate (H) of strawberry latent ringspot Nepovirus (SLRSV) was determined from cDNA copies and the 5 ' end sequence was deduced from directly sequenced virion RNA. At the 3 ' end a poly(A) sequence was identified. A long open reading frame encoding a polypeptide of 331 amino acids (Mr 36488) was determined. Sequence comparisons showed that SLRSV satellite RNA has no extensive homology with other sequences in the GenEmbl and Swiss-Prot databases. Strawberry latent ringspot (SLRSV) is provisionally classified in the Nepovirus genus of the proposed family Comoviridae (Martelli, 1992). The virus is transmitted by longidorid nematodes (Lister, 1964) and has a bipartit
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of a birch isolate of cherry leaf roll Nepovirus is also present, in part, in a rhubarb isolate
2013Co-Authors: N.w. Scott, J. I. Cooper, Y. Liu Y. T, C. U. T. HellenAbstract:A series of cDNA clones has been made from the birch isolate of cherry leaf roll Nepovirus. Restriction enzyme analysis and sequencing showed that at the 3 ' end, RNA-1 and RNA-2 are identical for 1.5 kb. Also a 0.7 kb 3 ' end homology exists between the birch and rhubarb isolate. These sequences do not seem to code for any proteins; however, the sequence conservation points to a role in virus replication. Cherry leaf roll Nepovirus (CLRV) has a bipartite genome composed of positive-sense ssRNA. The RNA-1 and RNA-2 are of Mf 2-82 x 106 and 2-29 x 106 respectively (Murant et al., 1981). They have a genomelinked protein (VPg) at the 5 ' end and are polyadenylated at the 3 ' end (Jones, 1985; Hellen & Cooper, 1987). Isolates of CLRV from different plant hosts are all of
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The identification, cloning, and sequence analysis of the coat protein coding region of a birch isolate (I2) of cherry leaf roll Nepovirus.
Archives of virology, 1993Co-Authors: N.w. Scott, J. I. Cooper, M L EdwardsAbstract:The coat protein gene of RNA-2 of cherry leaf roll Nepovirus (CLRV) birch isolate I2 was cloned, identified, and sequenced. Transcripts derived from cDNA to the coat protein gene made a polypeptide of Mr 51.5 k when translated in vitro. The predicted amino acid sequence of the coat protein showed little identity with Nepoviruses having small RNA-2s. It did, however, have 27% sequence identity with the coat protein of tomato ringspot Nepovirus which, like CLRV, has a relatively large RNA-2.
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Arabis mosaic Nepovirus coat protein in transgenic tobacco lessens disease severity and virus replication
Annals of Applied Biology, 1992Co-Authors: David J. Bertioli, M L Edwards, J. I. Cooper, W. S. HawesAbstract:Summary Tobacco plants expressing the coat protein of a lilac isolate of arabis mosaic virus (ArMV) poorly supported the replication of this virus and did not display any of the signs of systemic invasion produced in their untransformed counterparts or in transgenic plants expressing a different gene (β-glucuronidase). These effects, were manifest whether the inoculum was virions or RNA. This is the first report of such coat protein protection with a Nepovirus.
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A 1.5 kb sequence homology in 3'-terminal regions of RNA-1 and RNA-2 of a birch isolate of cherry leaf roll Nepovirus is also present, in part, in a rhubarb isolate.
The Journal of general virology, 1992Co-Authors: N.w. Scott, J. I. Cooper, Y Y Liu, C. U. T. HellenAbstract:A series of cDNA clones has been made from the birch isolate of cherry leaf roll Nepovirus. Restriction enzyme analysis and sequencing showed that at the 3' end, RNA-1 and RNA-2 are identical for 1.5 kb. Also a 0.7 kb 3' end homology exists between the birch and rhubarb isolate. These sequences do not seem to code for any proteins; however, the sequence conservation points to a role in virus replication.
Kirsi Lehto - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization of a satellite RNA associated with blackcurrant reversion Nepovirus.
Archives of virology, 2000Co-Authors: S Latvala-kilby, A. Lemmetty, Kirsi LehtoAbstract:A satellite RNA (satRNA) associated with blackcurrant reversion Nepovirus (BRV) was isolated and its nucleotide sequence was determined from cDNA clones. BRV satRNA was 1432 nucleotides (nt) in length excluding the poly(A)-tail, and contained one open reading frame which encodes a polypeptide of 402 amino acids, with a calculated Mr of 44 220. The coding region was bordered by a 5′ leader sequence of 25 nt and a 3′-nontranslated region of 201 nt. Two in vitro translation products of approximately 45 kDa and 40 kDa were detected, indicating that two in-frame AUG codons at positions 26 and 134 may both be functional. Nucleotide sequence comparisons revealed a stretch of 865 nt that was 63% identical between BRV satRNA and the large satRNA of chicory yellow mottle Nepovirus. A 5′-terminal consensus sequence and a 40 nt motif (located at positions 264–303 of BRV satRNA) were conserved between BRV satRNA and other nepoviral large satRNAs.
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The complete nucleotide sequence of RNA2 of blackcurrant reversion Nepovirus.
Virus research, 1999Co-Authors: S Latvala-kilby, Kirsi LehtoAbstract:Abstract The complete nucleotide sequence of blackcurrant reversion Nepovirus (BRV) RNA2 was determined from cDNA clones. RNA2 was 6400 nucleotides (nt) in length excluding the 3′ poly(A)-tail. It contained a single open reading frame of 4878 nts encoding a polypeptide of 1626 amino acids with a calculated M r of 178 860. The genome organization of BRV RNA2 was similar to that of other Nepoviruses, especially those with a large RNA2. The coat protein (CP) was located in the C-terminal region of the large polyprotein and contained amino acid motifs conserved among Nepovirus CPs. Sequence comparisons revealed a proline (P) residue surrounded by hydrophobic amino acid residues located upstream of the CP. This P motif is conserved among the putative movement proteins of nepo-, como-, caulimo- and capilloviruses. An N-terminal domain of 350 amino acids of RNA2-encoded polyprotein shared 34 and 35% sequence identity with the N-terminal domains of tomato ringspot Nepovirus RNA1- and RNA2-encoded polyproteins, respectively. Sequence identities between the N-terminal domains of BRV RNA2 and other nepoviral RNA2s were less than 20%; no common N-terminal motif was found.
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Characterization of the coat protein gene of mite-transmitted blackcurrant reversion associated Nepovirus
Virus research, 1998Co-Authors: Satu Latvala, Petri Susi, Nisse Kalkkinen, Kirsi LehtoAbstract:Abstract The nucleotide sequence of the 3′ terminal 3105 nucleotides (nt) of RNA2 of blackcurrant reversion associated virus (BRAV), the first mite-transmitted member of the Nepovirus group, has been determined. The sequence contains an open reading frame of 1744 nt in the virus-sense strand, a 3′ untranslated region of 1360 nt and a 3′ poly(A) tail. Analysis of the amino-terminal residues of purified coat protein (CP) suggests that the CP gene is located between nts 1361 and 2959 (from the 3′ terminus) in the RNA2, and that Asp/Ser is the proteolytic cleavage site of CP in the RNA2 encoded polyprotein. The predicted translation product from the CP gene is a polypeptide of 533 amino acids with a calculated M r of 57 561. The amino acid sequence of BRAV CP showed highest similarity to blueberry leaf mottle virus (BLMV), and tomato ringspot virus (ToRSV), two members of the proposed sub-group three of Nepoviruses possessing large RNA2 components. Nucleic and amino acid sequence comparisons between BRAV CP and the CPs of other Nepoviruses indicate that specific conserved Nepovirus CP domains occur in the BRAV CP thus confirming that BRAV is a member of the subgroup three of Nepoviruses.
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characterization of the coat protein gene of mite transmitted blackcurrant reversion associated Nepovirus
Virus Research, 1998Co-Authors: Satu Latvala, Petri Susi, Nisse Kalkkinen, Kirsi LehtoAbstract:The nucleotide sequence of the 3' terminal 3105 nucleotides (nt) of RNA2 of blackcurrant reversion associated virus (BRAV), the first mite-transmitted member of the Nepovirus group, has been determined. The sequence contains an open reading frame of 1744 nt in the virus-sense strand, a 3' untranslated region of 1360 nt and a 3' poly(A) tail. Analysis of the amino-terminal residues of purified coat protein (CP) suggests that the CP gene is located between nts 1361 and 2959 (from the 3' terminus) in the RNA2, and that Asp/Ser is the proteolytic cleavage site of CP in the RNA2 encoded polyprotein. The predicted translation product from the CP gene is a polypeptide of 533 amino acids with a calculated Mr of 57 561. The amino acid sequence of BRAV CP showed highest similarity to blueberry leaf mottle virus (BLMV), and tomato ringspot virus (ToRSV), two members of the proposed sub-group three of Nepoviruses possessing large RNA2 components. Nucleic and amino acid sequence comparisons between BRAV CP and the CPs of other Nepoviruses indicate that specific conserved Nepovirus CP domains occur in the BRAV CP thus confirming that BRAV is a member of the subgroup three of Nepoviruses. reserved.
Olivier Gall - One of the best experts on this subject based on the ideXlab platform.
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Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus
Archives of Virology, 2009Co-Authors: Joan Wellink, Olivier Gall, Alexander Karasev, René Vlugt, Thierry WetzelAbstract:The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus , Fabavirus and Nepovirus ) and Sequiviridae (genera Sequivirus and Waikavirus ) and into the unassigned genera Cheravirus and Sadwavirus . These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed “Secoviridae” to include the genera Comovirus , Fabavirus , Nepovirus , Cheravirus , Sadwavirus , Sequivirus and Waikavirus . Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae.
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An RNA-dependent-RNA-polymerase activity associated with grapevine chrome mosaic Nepovirus infection
Archives of Virology, 1997Co-Authors: Olivier Gall, Thierry Candresse, Jean DunezAbstract:A virus-induced, viral RNA-specific, RNA-dependent-RNA-poly-merase activity has been observed in vitro associated with membrane extracts of plants of three different species after infection with grapevine chrome mosaic Nepovirus (GCMV). The products of this activity are full-length, positive sense GCMV RNAs present in double-stranded structures. As has been demonstrated for a relative to Nepoviruses, cowpea mosaic comovirus, this activity probably corresponds to the nepoviral replication complex.
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Genetically engineered resistance against grapevine chrome mosaic Nepovirus
Plant Molecular Biology, 1993Co-Authors: Veronique Brault, Olivier Gall, Thierry Candresse, René Pierre Delbos, Maryvonne Lanneau, Jean DunezAbstract:Nepoviruses are a group of isometric plant viruses with a genome divided between two-single-stranded, positive-sense, RNA molecules. They are usually transmitted by nematodes and a number of them have significant economic impact, especially in perennial crops such as grapevine and fruit trees. Like all other picorna-like viruses, Nepoviruses express their coat protein (CP) as part of a larger polyprotein which is further processed by a virus-encoded protease, a feature which poses specific problems when trying to express the viral coat protein in transgenic plants. A hybrid gene, driving the high-level expression of the CP of grapevine chrome mosaic Nepovirus (GCMV) has been constructed and transferred to the genome of tobacco plants. Progeny of CP-expressing transformants show resistance against GCMV. When compared to control plants, fewer inoculated plants become infected and those that become infected accumulate reduced levels of viral RNAs. This protection was also shown to be efficient when plants are inoculated with purified viral RNA.