The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Baozhong Meng - One of the best experts on this subject based on the ideXlab platform.
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Grapevine rupestris stem pitting-associated virus: A Decade of Research and Future Perspectives
2020Co-Authors: Baozhong Meng, Dennis GonsalvesAbstract:Grapevine rupestris stem pitting-associated virus (GRSPaV), a recently identified virus, is classified as a member of the Foveavirus genus within the Flexiviridae family. The genome of GRSPaV is a single-stranded RNA of positive polarity and encodes five open reading frames (ORFs). ORF1 codes for a replicase polyprotein, which contains sequence domains conserved among Alphavirus-like superfamily of RNA viruses. GRSPaV also encodes three movement proteins, a feature distinct from most plant RNA viruses with a single movement protein. In this communication, we review the advancements that have been made on the virus over the past decade. GRSPaV has been demonstrated to comprise a family of molecular variants. Phylogenetic analyses reveal the presence of at least four distinct variant (lineage) groups. The genome of an isolate representing each of the viral variant groups has been sequenced. It is also demonstrated that commercial grape varieties are usually infected with mixtures of distinct viral variants, whereas rootstock varieties, at least those tested, are infected with a single variant. A specific relationship between some of the viral variant groups and distinct Vitis species seems to exist. Based on available information, a hypothetical model is proposed to explain the possible origin and evolution of different GRSPaV strains. The possible role of GRSPaV in the diseases Rupestris Stem Pitting and Vein Necrosis, as well as its economic importance are discussed. Lastly, we present our views on future directions for GRSPaV research.
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Grapevine rupestris stem pitting-associated virus.
Grapevine Viruses: Molecular Biology Diagnostics and Management, 2017Co-Authors: Baozhong Meng, A. RowhaniAbstract:Grapevine rupestris stem pitting-associated virus (GRSPaV) is a member of the genus Foveavirus (family Betaflexiviridae, order Tymovirales). GRSPaV was discovered in 1998 from grapevines affected with Rupestris stem pitting, a widespread graft-transmissible disease among commercial grapevines worldwide. Later research has demonstrated that different genetic variants of GRSPaV are closely associated with, and likely the causal agent of, Rupestris stem pitting and vein necrosis. However, definitive proof for its etiological role in either disease is lacking. In the past two decades, much progress has been made in several fronts concerning this virus. Compelling evidence demonstrates that GRSPaV comprises a wide range of genetic variants differing extensively in genome sequence. To date, the complete or near-complete genomes of 15 isolates have been sequenced. Phylogenetic analyses revealed the existence of eight clusters of viral variants. Interestingly, the population structure of GRSPaV differs sharply depending on whether the infected plant is a rootstock or a scion cultivar. GRSPaV exists as a uniform population in rootstocks, with GRSPaV-1 being detected in Vitis riparia and its hybrids, while GRSPaV-SG1 detected in Vitis rupestris and its hybrids. In contrast, commercial grape cultivars are generally infected with mixtures of distinct variants. Quick, reliable, and sensitive methods have been developed to detect GRSPaV. The subcellular localization of proteins encoded by GRSPaV has been elucidated using fluorescent protein tagging and microscopy. The establishment of infectious GRSPaV clones has enabled diverse investigations on gene function and viral replication and, ultimately, the development of GRSPaV as a vector for various applications. It is hoped that GRSPaV would ultimately serve as an excellent model system for the study of members of the family Betaflexiviridae and perhaps many other viruses that infect woody fruit crops.
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The triple gene block movement proteins of a grape virus in the genus Foveavirus confer limited cell-to-cell spread of a mutant Potato virus X
Virus Genes, 2013Co-Authors: Krinpreet Mann, Baozhong MengAbstract:Grapevine rupestris stem pitting - associated virus (GRSPaV) is a member of the genus Foveavirus in the family Betaflexiviridae . The genome of GRSPaV encodes five proteins, among which are three movement proteins designated the triple gene block (TGB) proteins. The TGB proteins of GRSPaV are highly similar to their counterparts in Potato virus X (PVX), as reflected in size, modular structure, conservation of critical amino acid sequence motifs, as well as similar cellular localization. Based on these similarities, we predicted that the TGB proteins of these two viruses would be interchangeable. To test this hypothesis, we replaced the entire or partial sequence of PVX TGB with the corresponding regions from GRSPaV, creating chimeric viruses that contain the PVX backbone and different sequences from GRSPaV TGB. These chimeric constructs were delivered into plants of Nicotiana benthamiana through agro-infiltration to test whether they were capable of cell-to-cell and systemic movement. To our surprise, viruses derived from pPVX.GFP_(CH3) bearing GRSPaV TGB in place of PVX TGB lost the ability to move either cell-to-cell or systemically. Interestingly, another chimeric virus resulting from pPVX.GFP_(HY2) containing four TGB genes (TGB1 from PVX and TGB1-3 from GRSPaV), exhibited limited cell-to-cell, but not systemic, movement. Our data question the notion that analogous movement proteins encoded by even distantly related viruses are functionally interchangeable and can be replaced by each other. These data suggest that other factors, besides the TGB proteins, may be required for successful intercellular and/or systemic movement of progeny viruses. This is the first experimental demonstration that the GRSPaV TGB function as movement proteins in the context of a chimeric virus and that four TGB genes were required to support the intercellular movement of the chimeric virus.
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construction and biological activities of the first infectious cdna clones of the genus Foveavirus
Virology, 2013Co-Authors: Baozhong Meng, Srividhya Venkataraman, Caihong Li, Weizhou Wang, Cathy Dayanglick, Munir MawassiAbstract:Grapevine rupestris stem pitting-associated virus (GRSPaV, genus Foveavirus, family Betaflexiviridae) is one of the most prevalent viruses in grapevines and is associated with three distinct diseases: rupestris stem pitting, vein necrosis and Syrah decline. Little is known about the biology and pathological properties of GRSPaV. In this work, we engineered a full-length infectious cDNA clone for GRSPaV and a GFP-tagged variant, both under the transcriptional control of Cauliflower mosaic virus 35 S promoter. We demonstrated that these cDNA clones were infectious in grapevines and Nicotiana benthamiana through fluorescence microscopy, RT-PCR, Western blotting and immuno electron microscopy. Interestingly, GRSPaV does not cause systemic infection in four of the most commonly used herbaceous plants, even in the presence of the movement proteins of two other viruses which are known to complement numerous movement-defective viruses. These infectious clones are the first of members of Foveavirus which would allow further investigations into mechanisms governing different aspects of replication for GRSPaV and perhaps related viruses.
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Detection of multiple sequence variants of Grapevine rupestris stem pitting-associated virus using primers targeting the polymerase domain and partial genome sequencing of a novel variant
Annals of Applied Biology, 2011Co-Authors: F. Terlizzi, Claudio Ratti, C. Li, R. Credi, Baozhong MengAbstract:Grapevine rupestris stem pitting-associated virus (GRSPaV) is a member of the genus Foveavirus within the new family Betaflexiviridae. GRSPaV is distributed among grapevines worldwide and is implicated in the disease rupestris stem pitting (RSP) of the rugose wood complex and two other disorders. GRSPaV is composed of a wide range of sequence variants, and so far, the complete genomes of five sequence variants have been sequenced. Quick and reliable detection of different GRSPaV variants is a critical step in the elimination and control of GRSPaV. Previously, primers designed from various genomic regions have been used in RT-PCR for the detection of GRSPaV variants. The efficiency of RT-PCR varied widely depending on the spectrum of the primers that were used. In this study, we designed a pair of degenerate primers based on the consensus sequence of the genomic region encoding the highly conserved RNA-dependent RNA polymerase domain from five reference isolates of GRSPaV for which the genome sequence are available. We demonstrate that this set of primers is comparable, if not superior, to the broad-spectrum primers RSP13&14 in detecting multiple GRSPaV variants. Using these degenerate primers, we identified two new and distinct sequence variants. The 3′ terminal genomic region of one of the new variants, GRSPaV-ML, spanning the 3′ part of ORF1, through the entire open reading frames 2–4, and the 5′ region of ORF5 were sequenced. Sequence comparison demonstrates that GRSPaV-ML is distinct from each of the five reference isolates.
Thierry Candresse - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterisation of an unidentifiel Flexivirus
2020Co-Authors: Pierre-yves Teycheney, Laurence Svanella-dumas, Armelle Marais, Thierry CandresseAbstract:Phylogenic studies undertaken on Banana mild mosaic virus (BanMMV) populations led to the characterisation of a 230 nt sequence originating from a yet unidentified virus in one of the 69 accessions analysed. No visible symptom was associated with the presence of this virus. 3' RACE experiments were performed on double stranded RNAs purified from this accession, enabling the cloning and sequencing of about 2.3 kb of the 3' end region of the genome of this virus. Based on sequence comparisons, the analysis of the cloned sequence showed the presence of 5 open reading frames (ORFs) encoding an RNA dependent RNA polymerase (RdRp), three proteins involved in virus movement and organised as a triple gene block (TGB1, TGB2 and TGB3) and a coat protein, respectively. The genomic RNA ends in a short 3' non-coding region followed by a polyA tail. Sequence comparisons and phylogenic analyses performed on both nucleotide and amino acid sequences led to the conclusion that this virus, tentatively named Banana X virus (BanXV) seems to represent a new agent since it shows only distant relationships with viral sequences present in databanks. It probably belongs to a new genus within the Flexiviridae family and is very distantly related to members of other genera in this family such as the genus Foveavirus. Results of further molecular work aimed at unravelling BanXV expression strategy will also be presented and discussed (Texte integral).
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New Insights into Asian Prunus Viruses in the Light of NGS-Based Full Genome Sequencing.
PLOS ONE, 2016Co-Authors: Armelle Marais, Chantal Faure, Thierry CandresseAbstract:Double stranded RNAs were purified from five Prunus sources of Asian origin and submitted to 454 pyrosequencing after a random, whole genome amplification. Four complete genomes of Asian prunus virus 1 (APV1), APV2 and APV3 were reconstructed from the sequencing reads, as well as four additional, near-complete genome sequences. Phylogenetic analyses confirmed the close relationships of these three viruses and the taxonomical position previously proposed for APV1, the only APV so far completely sequenced. The genetic distances in the respective polymerase and coat protein genes as well as their gene products suggest that APV2 should be considered as a distinct viral species in the genus Foveavirus, even if the amino acid identity levels in the polymerase are very close to the species demarcation criteria for the family Betaflexiviridae. However, the situation is more complex for APV1 and APV3, for which opposite conclusions are obtained depending on the gene (polymerase or coat protein) analyzed. Phylogenetic and recombination analyses suggest that recombination events may have been involved in the evolution of APV. Moreover, genome comparisons show that the unusually long 3’ non-coding region (3' NCR) is highly variable and a hot spot for indel polymorphisms. In particular, two APV3 variants differing only in their 3’ NCR were identified in a single Prunus source, with 3' NCRs of 214–312 nt, a size similar to that observed in other Foveaviruses, but 567–850 nt smaller than in other APV3 isolates. Overall, this study provides critical genome information of these viruses, frequently associated with Prunus materials, even though their precise role as pathogens remains to be elucidated.
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First Report of Apricot pseudo-chlorotic leaf spot virus Infecting Plum (Prunus domestica) in the Czech Republic
Plant Disease, 2012Co-Authors: Dana Šafářová, Thierry Candresse, Milan Navrátil, Chantal Faure, Armelle MaraisAbstract:Apricot pseudo-chlorotic leaf spot virus (APCLSV) is a novel, still poorly known Trichovirus in the family Betaflexiviridae. It is most closely related to Apple chlorotic leaf spot virus (ACLSV) (2,4) and infects stone fruit trees of the Prunus genus. Its presence has so far been detected in apricot, plum, Japanese plum, and peach trees in Italy, Spain, France, Hungary, Turkey, Jordan, and Australia (1,2,4). During the summers of 2008 and 2010, leaf samples of old Czech local plum cultivars were obtained from the Holovousy collection and assessed for the presence of viruses belonging to the Capillovirus, Trichovirus, and Foveavirus genera using the polyvalent degenerate oligonucleotides (PDO) nested reverse transcription (RT)-PCR test (3). Following amplification from total RNAs extracts, the amplicons were cloned and several clones were sequenced for each plant sample. In plum (Prunus domestica) cv. Babce, a mixture of amplicons was observed and BlastN and BlastX analyses of the obtained sequences reveal...
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Characterization of Prunus-infecting apricot latent virus-like Foveaviruses: evolutionary and taxonomic implications.
Virus Research, 2010Co-Authors: Fater Youssef, P. Gentit, Armelle Marais, Chantal Faure, M. Barone, Thierry CandresseAbstract:Abstract The complete genomic sequences of four Prunus -infecting Apricot latent virus (ApLV) like isolates were determined and used to analyze the taxonomic position and variability of these viruses. The results indicate that all isolates show a typical Foveavirus genetic organization. Despite an average 23% nucleotide divergence, they show strong colinearity with only three regions of significant indel variability, in the internal and 3′ non-coding regions and variable N-terminal half of the coat protein (CP). Sequence comparisons using the polymerase (Pol) and CP genes provide a conflicting taxonomic picture, with divergence level in the Pol and CP genes suggesting the existence of a single or of two species, respectively. However, a range of considerations argue that all four isolates should likely be considered as belonging to the ApLV species. ApLV is closely related to Apple stem pitting virus and could be considered a sister species to it, with ASPV being specialized to infect members of the Maloideae family and ApLV members of the Prunoideae. Analysis of selection pressures affecting the five open reading frames of ApLV and ASPV identified two regions under strong purifying selection, that coding for the conserved C-terminal half of the CP and the gene coding for the first protein of the triple gene block (TGBp1).
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Polyvalent degenerate oligonucleotides reverse transcription-polymerase chain reaction: a polyvalent detection and characterization tool for trichoviruses, capilloviruses, and Foveaviruses.
Phytopathology, 2005Co-Authors: Xavier Foissac, P. Gentit, Laurence Svanella-dumas, Marie-josée Dulucq, Armelle Marais, Thierry CandresseAbstract:Foissac, X., Svanella-Dumas, L., Gentit, P., Dulucq, M.-J., Marais, A., and Candresse, T. 2005. Polyvalent degenerate oligonucleotides reverse transcription-polymerase chain reaction: A polyvalent detection and characterization tool for trichoviruses, capilloviruses, and Foveaviruses. Phytopathology 95:617-625. A polyvalent nested reverse transcription-polymerase chain reaction (RT-PCR) test using degenerate primers containing inosine (polyvalent degenerate oligonucleotides [PDO]) was developed for filamentous fruit tree viruses belonging to the genera Trichovirus, Capillovirus, and Foveavirus. The 362-bp product was amplified from nucleic acid extracts obtained from Prunus and Malus leaf samples. All the viruses targeted were detected, demonstrating the polyvalence of the test. The variability of a collection of Apple chlorotic leaf spot virus isolates was analyzed using the sequence of the PDO RT-PCR amplified cDNAs. The technique was also used to screen stone fruit materials infected with known agents or with virus-like graft-transmissible diseases of unknown etiology. The results obtained further validated the broad specificity of the assay, with positive amplification obtained for uncharacterized or partially characterized viruses associated with cherry and peach disorders. Sequencing the amplified PCR products either directly or after cloning allowed the identification of variants of known agents and the tentative identification of two new agents, a Trichovirus and a Foveavirus. In addition, sequence comparisons demonstrated that the sequence of the targeted region is phylogenetically informative and of predictive taxonomic value.
P. Gentit - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Prunus-infecting apricot latent virus-like Foveaviruses: evolutionary and taxonomic implications.
Virus Research, 2010Co-Authors: Fater Youssef, P. Gentit, Armelle Marais, Chantal Faure, M. Barone, Thierry CandresseAbstract:Abstract The complete genomic sequences of four Prunus -infecting Apricot latent virus (ApLV) like isolates were determined and used to analyze the taxonomic position and variability of these viruses. The results indicate that all isolates show a typical Foveavirus genetic organization. Despite an average 23% nucleotide divergence, they show strong colinearity with only three regions of significant indel variability, in the internal and 3′ non-coding regions and variable N-terminal half of the coat protein (CP). Sequence comparisons using the polymerase (Pol) and CP genes provide a conflicting taxonomic picture, with divergence level in the Pol and CP genes suggesting the existence of a single or of two species, respectively. However, a range of considerations argue that all four isolates should likely be considered as belonging to the ApLV species. ApLV is closely related to Apple stem pitting virus and could be considered a sister species to it, with ASPV being specialized to infect members of the Maloideae family and ApLV members of the Prunoideae. Analysis of selection pressures affecting the five open reading frames of ApLV and ASPV identified two regions under strong purifying selection, that coding for the conserved C-terminal half of the CP and the gene coding for the first protein of the triple gene block (TGBp1).
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Asian prunus viruses: New related members of the family Flexiviridae in Prunus germplasm of Asian origin.
Virus research, 2006Co-Authors: A Marais, P. Gentit, L Svanella-dumas, X Foissac, T CandresseAbstract:Serological reactivity to Plum pox virus (PPV) antisera has been described in several Prunus sources of Asian origin that are free of PPV infection. Using polyvalent or specific PCR assays, the presence of three closely related agents in two of these sources, Prunus mume cv. Bungo and P. persica cv. Ku Chu'a Hung, was demonstrated. Similarities in genome organization and sequence comparisons indicate that these agents should be regarded as members of the genus Foveavirus, their only singular trait being a very large (>800 nt) 3' non-coding region (NCR), as compared to the ca. 130-180 nt 3' NCR observed in other Foveaviruses. The three agents are very divergent from known Foveaviruses but are also significantly removed one from the others, with overall nucleotide sequence identity levels in the sequenced region of ca. 74-76% and of only 60.8-67.5% in their complete CP gene (61.9-71.3% amino acid sequence identity). Given the species discrimination criteria in the family Flexiviridae, these three agents should be regarded as three related yet distinct new viruses belonging to the Foveavirus genus, for which the names Asian prunus virus 1, 2 and 3 are proposed. Evidence is provided for the presence of variants of these new viruses in other Prunus germplasm of Asian origin.
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Polyvalent degenerate oligonucleotides reverse transcription-polymerase chain reaction: a polyvalent detection and characterization tool for trichoviruses, capilloviruses, and Foveaviruses.
Phytopathology, 2005Co-Authors: Xavier Foissac, P. Gentit, Laurence Svanella-dumas, Marie-josée Dulucq, Armelle Marais, Thierry CandresseAbstract:Foissac, X., Svanella-Dumas, L., Gentit, P., Dulucq, M.-J., Marais, A., and Candresse, T. 2005. Polyvalent degenerate oligonucleotides reverse transcription-polymerase chain reaction: A polyvalent detection and characterization tool for trichoviruses, capilloviruses, and Foveaviruses. Phytopathology 95:617-625. A polyvalent nested reverse transcription-polymerase chain reaction (RT-PCR) test using degenerate primers containing inosine (polyvalent degenerate oligonucleotides [PDO]) was developed for filamentous fruit tree viruses belonging to the genera Trichovirus, Capillovirus, and Foveavirus. The 362-bp product was amplified from nucleic acid extracts obtained from Prunus and Malus leaf samples. All the viruses targeted were detected, demonstrating the polyvalence of the test. The variability of a collection of Apple chlorotic leaf spot virus isolates was analyzed using the sequence of the PDO RT-PCR amplified cDNAs. The technique was also used to screen stone fruit materials infected with known agents or with virus-like graft-transmissible diseases of unknown etiology. The results obtained further validated the broad specificity of the assay, with positive amplification obtained for uncharacterized or partially characterized viruses associated with cherry and peach disorders. Sequencing the amplified PCR products either directly or after cloning allowed the identification of variants of known agents and the tentative identification of two new agents, a Trichovirus and a Foveavirus. In addition, sequence comparisons demonstrated that the sequence of the targeted region is phylogenetically informative and of predictive taxonomic value.
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first report on the natural occurrence of cherry virus a in mirabelle plum prunus domestica var insititia
Plant Disease, 2005Co-Authors: L Svanelladumas, P. Gentit, Armelle Marais, J Lamorte, Thierry CandresseAbstract:Cherry virus A (CVA) is a member of the Capillovirus genus (2). It was discovered serendipitously during cloning of the little cherry agent (2) and has since been shown to be relatively widespread in sweet and sour cherry (Prunus cerasus and P. avium) (2,3). It is currently unclear whether CVA is associated with any specific symptoms in these hosts. Although it can be transmitted by grafting and thus propagated in peach, it has not been reported to naturally infect any host other than cherry. Using a degenerate reverse transcription-polymerase chain reaction (RT-PCR) technique targeting a conserved region of the RNA-dependent RNA polymerase (RdRp) and allowing the amplification of members of the Trichovirus, Capillovirus, and Foveavirus genera of filamentous plant viruses (1), a number of symptomatic Prunus spp. germplasm were evaluated. Among these, a cv. Mirabelle doree accession (Prunus domestica var. insititia P332) of French origin exhibited severe symptoms of rosetting, severe leaf and fruit deforma...
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Molecular characterization of Foveaviruses associated with the cherry necrotic mottle leaf disease and complete sequencing of an European isolate of cherry green ring mottle virus
Archives of Virology, 2002Co-Authors: P. Gentit, M. Peypelut, L Svanella-dumas, X Foissac, G. Macquaire, T CandresseAbstract:Analysis of the P1C124 source (associated with the cherry necrotic mottle leaf (CNML) disease) revealed the presence of two different viral agents. The complete nucleotide sequence of one of these agents, P1A, had an overall nucleotide sequence similarity of 83% with a previously sequenced North American isolate of Cherry green ring mottle virus (CGRMV) and should therefore be regarded as an European isolate of CGRMV. Approximately 2 kb of the 5′ end of the genome of the second agent, P1B, were also sequenced and were shown to be 82% homologous with Cherry necrotic rusty mottle virus (CNRMV), another member of the Foveavirus genus. The possible involvement of CGRMV-P1A and of CNRMV-P1B in the etiology of the CNML disease is discussed.
W. Jelkmann - One of the best experts on this subject based on the ideXlab platform.
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Identification and complete genome analysis of a virus variant or putative new Foveavirus associated with apple green crinkle disease
Archives of Virology, 2013Co-Authors: D. James, A. Varga, G. D. Jesperson, M. Navratil, D. Safarova, F. Constable, M. Horner, K. Eastwell, W. JelkmannAbstract:A virus identified as “apple green crinkle associated virus” (AGCaV) was isolated from Aurora Golden Gala apple showing severe symptoms of green crinkle disease. Evidence was obtained of a potential causal relationship to the disease. The viral genome consists of 9266 nucleotides, excluding the poly(A) tail at the 3’-terminus. It has a genome organization similar to that of members of the species Apple stem pitting virus (ASPV), the type species of the genus Foveavirus , family Betaflexiviridae . ORF1 of AGCaV encodes a replicase-complex polyprotein with a molecular mass of 247 kDa; the proteins of ORFs 2, 3, and 4 (TGB proteins) are estimated to be 25.1 kDa, 12.8 kDa, and 7.4 kDa, respectively; and ORF5 encodes the CP, with an estimated molecular mass of 43.3 kDa. Interestingly, AGCaV utilizes different stop codons for ORF1, ORF3, and ORF5 compared to the ASPV type isolate PA66, and between the two viruses, six distinct indel events were observed within ORF5. AGCaV has four non-coding regions (NCRs), including a 5’-NCR (60 nt), a 3’-NCR (134 nt), and two intergenic (IG) NCRs: IG-NCR1 (69 nt) and IG-NCR2 (91 nt). A conserved stable hairpin structure was identified in the variable 5’-NCR of members of the genus Foveavirus . AGCaV may be a variant or strain of ASPV with unique biological properties, but there is evidence that it may be a distinct putative Foveavirus.
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Investigation of virus occurrence in different tissues throughout the year and sequence variability of Apple stem pitting virus
Julius-Kühn-Archiv, 2010Co-Authors: A. Arntjen, W. JelkmannAbstract:The occurrence of Apple stem pitting virus (ASPV) isolate PB 66 in three different types of tissue of four different apple varieties throughout the year was determined. Reliable virus detection in phloem tissue was observed in all four apple varieties investigated, at all sampling dates during the year. The complete nucleotide sequence of ASPV isolate PB 66 was determined and compared to ASPV isolate PA 66. The isolates show 80 % sequence identity. Comparison of the ASPV PA 66 coat protein amino acids sequence with 16 other ASPV isolates from different hosts revealed an insertion event of 18 amino acids. Keywords : Apple stem pitting virus , Foveavirus, Flexiviridae
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Development of PCR primer pairs for the characterization and detection of several related filamentous viruses of cherry
Acta Horticulturae, 2001Co-Authors: M.e. Rott, W. JelkmannAbstract:Cherry can be infected by a number of mottling diseases caused by either filamentous viruses or suspected of being caused by filamentous viruses. The causal agents for two of these diseases have been previously described, Cherry green ring mottle virus (CGRMV) a tentative member of the Foveaviruses, and Cherry mottle leaf virus (CMLV) a member of the trichoviruses. In a separate article we also present the complete nucleotide sequence of Cherry necrotic rusty mottle virus (CNRMV). For the mottling diseases, cherry rusty mottle (CRM) and cherry necrotic mottling (CNM), data is presented identifying viruses associated with each disease. Viruses associated with European isolates of cherry mottle leaf (CML) CRM, CNRM and CNM all appear to be closely related to CGRMV and can be tentatively included in the Foveavirus genus. An additional, related virus, was discovered during the course of these studies and would appear to be a fairly common latent virus of cherry. It is currently unclear whether this virus is associated with cherry mottling disease (CMot), or is a previously undescribed virus. Several RT-PCR primers are presented for the detection of the different viruses.
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Characterization and Detection of Several Filamentous Viruses of Cherry: Adaptation of an Alternative Cloning Method (DOP-PCR), and Modification of an RNA Extraction Protocol
European Journal of Plant Pathology, 2001Co-Authors: M.e. Rott, W. JelkmannAbstract:For the identification and analysis of new RNA plant viruses infecting fruit trees, an initial step often involves the laborious procedure of isolation and cDNA synthesis and cloning from purified viral dsRNA. For subsequent RT-PCR detection of these and other viruses from tissue with high phenolic and polysaccharide concentrations, a simple and efficient extraction protocol for viral nucleic acid is also important. A method for rapid cDNA cloning from small amounts of purified dsRNA using a modification of degenerate oligo primed polymerase chain reaction mbox(DOP-PCR), and a modification of a protocol for effective extraction of viral RNA for use in RT-PCR are presented. Both methods were used to analyze a number of mottling diseases described in cherry. The causal agents for two of these diseases have been previously described, Cherry green ring mottle virus, a tentative member of the Foveaviruses, and Cherry mottle leaf virus , a member of the trichoviruses. For the diseases cherry rusty mottle and cherry necrotic rusty mottle, data are presented identifying viruses associated with each disease. Viruses associated with cherry rusty mottle, cherry necrotic rusty mottle and European isolates of cherry mottle leaf diseases, are closely related to Cherry green ring mottle virus and can be tentatively included in the Foveavirus genus. An additional virus, related to cherry green ring mottle virus, was discovered by RT-PCR cloning and appears to be a common latent virus of cherry. Finally, isolates of cherry necrotic mottle disease could be assayed positive by RT-PCR for a virus
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Foveavirus, a new plant virus genus
Archives of Virology, 1998Co-Authors: G. P. Martelli, W. JelkmannAbstract:Foveavirus is a novel genus of plant viruses with helically constructed filamentous particles ca. 800 nm long, typified by apple stem pitting virus (ASPV). Virions do not contain lipids or carbohydrates, have a positive sense, single-stranded, polyadenylated RNA genome 8.4 to 9.3 kb in size, and a single type of coat protein with a size of 28 to 44 kDa. The genome of definitive viral species is made up of five ORFs encoding respectively, the replication-related proteins (ORF 1), the putative movement proteins (ORF 2 to 4, constituting the triple block gene), and the coat protein (ORF 5). Virions accumulate in the cytoplasm, where replication is likely to occur with a strategy comparable to that of potexviruses, based on direct expression of the 5'-proximal ORF, and expression of downstream ORFs through subgenomic RNAs. No vector is known. Virus transmission is by grafting, and dispersal is through infected propagating material. The genome structure and organization (i.e. number and order of genes) closely resembles that of the genera Potexvirus, Carlavirus and Allexvirus , but ORF 1 and the coat protein cistron (ASPV only) are significantly larger.
G. P. Martelli - One of the best experts on this subject based on the ideXlab platform.
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Plant Virus Diseases: Fruit Trees and Grapevine
Encyclopedia of Virology, 2020Co-Authors: G. P. Martelli, J.k. UyemotoAbstract:Temperate fruit and nut trees and grapevines are susceptible to infections by viruses belonging to a number of different genera with isometric (Cheravirus, Ilarvirus, Maculavirus, Marafivirus Nepovirus, and Sadwavirus) and filamentous (Ampelovirus, Capillovirus, Closterovirus, Foveavirus Potyvirus, Trichovirus, and Vitivirus) particles. Viral infections induce symptoms on the leaves (chlorotic to yellow mottling, deformation, shredding), flowers (color break), trunk and branches (stunting, pitting, grooving), fruits (malformation, necrosis) and may lead to decline and death of the host. A few viruses (i.e., apple stem grooving virus (ASGV, capillovirus), apple stem pitting virus (ASPV, Foveavirus), grapevine leafroll-associated virus 2 (GLRaV-2, closterovirus), the maculaviruses grapevine fleck virus (GFkV), grapevine red globe virus (GRGV), the marafiviruses grapevine asteroid mosaic-associated virus (GAMaV), and grapevine vein feathering virus (GVFV)) lack recognized vectors and are disseminated by propagative material. By contrast, (1) most nepoviruses such as grapevine fanleaf virus (GFLV), tomato ringspot virus (ToRSV) and others, with cherry leaf roll virus (CLRV) being an exception, plus strawberry latent ringspot virus (SLRSV, sadwavirus), cherry rasp leaf virus (CRLV, cheravirus) are nematode-borne; (2) the ilarviruses prune dwarf virus (PDV), prunus necrotic ringspot virus (PNRSV), apple mosaic virus (ApMV), the nepovirus CLRV and the Foveavirus rupestris stem pitting associated virus (RSPaV) are pollen-borne or seed-borne or both; (3) the ampeloviruses grapevine leafroll-associated virus 1 and 3 (GLRaV-1 and GLRaV-3), little cherry virus 2 (LChV-2), and the vitiviruses grapevine virus A and B (GVA and GVB) are transmitted by mealybugs; (4) the trichoviruses peach mosaic virus (PcMV) and cherry mottle leaf virus (CMLV) have eryophid mite vectors; and (5) plum pox virus (PPV, potyvirus) is transmitted by aphids. Control is preventive and based primarily on the production and use of sanitized virus-tested material and implementation of sanitary selection and certification procedures.
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Complete nucleotide sequence of a new variant of grapevine rupestris stem pitting-associated virus from southern Italy.
Archives of Virology, 2011Co-Authors: M. Morelli, A. Minafra, Donato Boscia, G. P. MartelliAbstract:Grapevine rupestris stem pitting-associated virus (GRSPaV), genus Foveavirus, family Betaflexiviridae, is one of the most common viruses of grapevine and is widely distributed in many, if not all, grape-growing areas of the world. This virus is thought to be involved in the ‘rugose wood’ complex (RW) as the putative agent of the disorder known as Rupestris stem pitting (RSP) [1], and some of its strains have been shown to have a very close association with vein necrosis disease (VN) [2, 3]. This virus is also associated with Syrah decline [4], and its possible involvement in other disorders has also been suggested [5, 6]. Since the characterization of GRSPaV at the end of the 1990s [1, 7], a number of studies have revealed the remarkable genetic variability of this virus, which may reflect the puzzling pattern of its biological effects. Molecular investigations have led to complete sequencing of six viral isolates, named GRSPaV-1 (accession no. AF057136), GRSPV (AF026278), GRSPaV-SG1 (AY881626), GRSPaVBS (AY881627), GRSPaV-SY (AY368590) and GRSPaV-PN (AY368172). We now report the complete nucleotide (nt) sequence of a new viral isolate (GRSPaV-MG), deposited in GenBank under the accession number FR691076. Virus source and sequencing strategy
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Virology Division News: The new plant virus family Flexiviridae and assessment of molecular criteria for species demarcation
Archives of Virology, 2004Co-Authors: M. J. Adams, G. P. Martelli, T Candresse, J. F. Antoniw, M. Bar-joseph, A. A. Brunt, G. D. Foster, R. G. Milne, C. M. FauquetAbstract:The new plant virus family Flexiviridae is described. The family is named because its members have flexuous virions and it includes the existing genera Allexivirus , Capillovirus , Carlavirus , Foveavirus , Potexvirus , Trichovirus and Vitivirus , plus the new genus Mandarivirus together with some related viruses not assigned to any genus. The family is justified from phylogenetic analyses of the polymerase and coat protein (CP) sequences. To help to define suitable molecular criteria for demarcation of species, a complete set of pairwise comparisons was made using the nucleotide (nt) and amino acid (aa) sequences of each fully-sequenced gene from every available accession in the family. Based on the distributions and on inspection of the data, it was concluded that, as a general rule, distinct species have less than ca. 72% identical nt or 80% identical aa between their entire CP or replication protein genes.
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Foveavirus, a new plant virus genus
Archives of Virology, 1998Co-Authors: G. P. Martelli, W. JelkmannAbstract:Foveavirus is a novel genus of plant viruses with helically constructed filamentous particles ca. 800 nm long, typified by apple stem pitting virus (ASPV). Virions do not contain lipids or carbohydrates, have a positive sense, single-stranded, polyadenylated RNA genome 8.4 to 9.3 kb in size, and a single type of coat protein with a size of 28 to 44 kDa. The genome of definitive viral species is made up of five ORFs encoding respectively, the replication-related proteins (ORF 1), the putative movement proteins (ORF 2 to 4, constituting the triple block gene), and the coat protein (ORF 5). Virions accumulate in the cytoplasm, where replication is likely to occur with a strategy comparable to that of potexviruses, based on direct expression of the 5'-proximal ORF, and expression of downstream ORFs through subgenomic RNAs. No vector is known. Virus transmission is by grafting, and dispersal is through infected propagating material. The genome structure and organization (i.e. number and order of genes) closely resembles that of the genera Potexvirus, Carlavirus and Allexvirus , but ORF 1 and the coat protein cistron (ASPV only) are significantly larger.
