The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Fernando Garciaarenal - One of the best experts on this subject based on the ideXlab platform.
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analysis of the viability of coat protein hybrids between cucumber mosaic Virus and Tomato Aspermy Virus
Journal of General Virology, 2006Co-Authors: Susana Llamas, Ignacio M Moreno, Fernando GarciaarenalAbstract:Coat-protein (CP) hybrids between Cucumber mosaic Virus (CMV) and Tomato Aspermy Virus (TAV) were engineered to analyse reported CP-associated differences between these Viruses. CP portions delimited by aa 1–59, 60–148 and 149–219 were exchanged in all possible combinations within TAV RNA3. The seven possible chimeras were able to replicate in tobacco protoplasts to similar levels, but only those having residues 1–59 or 60–148 from CMV were infectious to tobacco plants, a common host for CMV and TAV, and formed stable particles. When most of the movement protein (MP) of TAV was substituted for that of CMV, infectivity of CP hybrids did not vary. No hybrid was able to infect cucumber plants, a host for CMV and not for TAV. Need for MP–CP compatibility could explain these results, but shows that MP–CP compatibility conditions the use of CP chimeras to map CP-associated differences between CMV and TAV.
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comparison of properties of particles of cucumber mosaic Virus and Tomato Aspermy Virus based on the analysis of molecular surfaces of capsids
Journal of General Virology, 2006Co-Authors: Luis F Pacios, Fernando GarciaarenalAbstract:The plant RNA Viruses Cucumber mosaic Virus (CMV) and Tomato Aspermy Virus (TAV) (genus CucumoVirus) have similar icosahedral particles, the crystal structures of which have been reported recently. Similarity in particle structure agrees with reports of stable capsids assembled from their capsid proteins and of viable recombinant Viruses with chimeric capsid proteins derived from CMV and TAV. However, differences between the cucumoViruses have been reported for physicochemical properties. Here, structural and electrostatic features of the molecular surfaces are studied to investigate their relationship with these observations. Two coat-protein recombinants with structures modelled by taking CMV and TAV as templates were also included in the analysis. Results show that there exists an external region of negative electrostatic potential that has arisen from strictly conserved charged residues situated near the external HI loop of the subunits in the capsomers. This negative domain surrounds the fivefold and quasi-sixfold axes and locates above regions of positive potential that extend to cover, nearly homogeneously, the inner surface of capsids, where interaction with encapsidated RNA occurs. Differences between the outer electrostatic distributions in CMV and TAV explain the distinct response of both Viruses to variations in physicochemical conditions required for particle stability and are essential to rationalize the biological activity of the coat-protein recombinants, in spite of their seemingly distinct electrostatic characteristics.
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the bundle sheath phloem interface of cucumis sativus is a boundary to systemic infection by Tomato Aspermy Virus
Molecular Plant-microbe Interactions, 1998Co-Authors: Jeremy R Thompson, Fernando GarciaarenalAbstract:The progress of infection of two cucumoViruses in cucumber plants was analyzed immunohistochemically. Strain Fny of cucumber mosaic Virus (CMV, FFF) was found to infect cucumber tissues systemically by 6 days postinoculation (dpi), while a reassortant Virus with RNAs 1+2 of Fny-CMV plus RNA3 of strain 1 of Tomato Aspermy Virus (FFT) was unable to move long distance and infect cucumber plants systemically. FFF infection of the vasculature was detected 6 dpi in the phloem of a low percentage of both minor (order VII–VI) and major (order V–IV) veins. At 9 dpi, infection was detected in phloem cells of about 50% of both minor and major veins. FFT colonization of inoculated cotyledons followed a pathway similar to that of FFF, but Virus accumulation was never detected in vascular tissues. In minor or major veins, FFT infection was arrested at the bundle sheath (BS), and at 9 dpi was not detected in intermediary or other phloem cells. Thus, our data indicate that the BS-phloem interface is a boundary for the sy...
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mapping helper Virus functions for cucumber mosaic Virus satellite rna with pseudorecombinants derived from cucumber mosaic and Tomato Aspermy Viruses
Virology, 1994Co-Authors: Enrique Moriones, Isabel Diaz, Aurora Fraile, Beatriz Fernandezcuartero, Xsef J Burgyn, Fernando GarciaarenalAbstract:Abstract P-TAV is a strain of Tomato Aspermy Virus (TAV) able to efficiently support the systemic accumulation of some (i.e., B2-satRNA) but not of other (i,e., Ix-satRNA) strains of the satellite RNA (satRNA) of cucumber mosaic Virus (CMV) in both tobacco and in Tomato. As reported for V-TAV, the failure to support the systemic accumulation of Ix-satRNA seems to be due to an inefficient support of its systemic movement. Pseudorecombinants obtained by the exchange of RNAs 1 + 2 between P-TAV and TrK7-CMV, an efficient helper for the systemic accumulation of Ix-satRNA, were assayed for their ability to support the accumulation of CMV-satRNAs in tobacco plants and protoplasts. Pseudorecombinants having RNAs 1 + 2 from CMV supported the systemic movement and accumulation of CMV-satRNA as efficiently as CMV, whereas pseudorecombinants having RNAs 1 + 2 from TAV supported the CMV-satRNA very poorly. Thus, the ability to support the systemic movement and accumulation of CMV-satRNA is determined primarily by RNAs 1 + 2 and not by RNA 3, which is presumed to encode movement functions in the cucumoViruses and only has a minor, modulating effect on the systemic accumulation of satRNA. This suggests that for systemic movement CMV-satRNA has to interact with (the gene products of) RNAs 1 and/or 2 or that these viral RNAs compete with the satRNA for interaction with the coat or other movement proteins.
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differential interactions among strains of Tomato Aspermy Virus and satellite rnas of cucumber mosaic Virus
Virology, 1992Co-Authors: Enrique Moriones, Isabel Diaz, Emilio Rodriguezcerezo, Aurora Fraile, Fernando GarciaarenalAbstract:Abstract Tomato and tobacco plants were inoculated with either of two strains of Tomato Aspermy Virus, 1-TAV or V-TAV, and each of six isolates of cucumber mosaic Virus satellite RNA (CMV-satRNA), B1, B2, B3, G, lx, or WL2. Ribonuclease protection assays, used to detect total satRNA and encapsidated satRNA, revealed that G-satRNA generated new satellite RNA not of the inoculated sequence. The other CMV-satRNAs were compared for their ability (1) to replicate, (2) to modulate symptoms, (3) to reduce TAV accumulation, and (4) to alter the extent of encapsidation of TAV genomic RNAs. The fraction of B2- and B3-satRNAs encapsidated was greater for 1-TAV than for WTAV, although spread and accumulation of the satRNA were similar for both helper Viruses. These results suggest that CMV-satRNA may spread in a nonencapsidated form. Accumulation of CMV-satRNA in systemically infected leaves was detected for all inoculum combinations except V-TAV and lx-satRNA, for which the satellite RNA increased only in protoplasts and inoculated leaves of tobacco or Tomato. In such inoculated leaves, lx-satRNA was not detected in capsids. Thus the effectiveness of the TAV helpers of CMV-satRNAs may be controlled in at least some instances by the extent of satRNA spread or encapsidation rather than by the efficiency of satRNA replication. In contrast to infections initiated by inoculation of CMV and CMV-satRNA, inoculation of 1-TAV or V-TAV and CMV-satRNA did not alter the relative amounts of viral genomic RNAs encapsidated or result in accumulation of large amounts of double-stranded satRNA.
Mark Tepfer - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of potential risks associated with recombination in transgenic plants expressing viral sequences.
The Journal of general virology, 2020Co-Authors: Camilla Turturo, Mireille Jacquemond, Jeremy R Thompson, Stephane Gaubert, Arianna Friscina, Mark TepferAbstract:Virus-resistant transgenic plants have been created primarily through the expression of viral sequences. It has been hypothesized that recombination between the viral transgene mRNA and the RNA of an infecting Virus could generate novel Viruses. As mRNA/viral RNA recombination can occur in Virus-resistant transgenic plants, the key to testing this risk hypothesis is to compare the populations of recombinant Viruses generated in transgenic and non-transgenic plants. This has been done with two cucumoviral systems, involving either two strains of cucumber mosaic Virus (CMV), or CMV and the related Tomato Aspermy Virus (TAV). Although the distribution of the sites of recombination in the CMV/CMV and TAV/CMV systems was quite different, equivalent populations of recombinant Viruses were observed in both cases. These results constitute the first comparison of the populations of recombinants in transgenic and non-transgenic plants, and suggest that there is little risk of emergence of recombinant Viruses in these plants, other than those that could emerge in non-transgenic plants.
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the 3 untranslated region of cucumber mosaic Virus cmv subgroup ii rna3 arose by interspecific recombination between cmv and Tomato Aspermy Virus
Journal of General Virology, 2009Co-Authors: Jeremy R Thompson, Mark TepferAbstract:Recombination in single-stranded RNA Viruses is one of the principal mechanisms responsible for their evolution. Here we show, using a variety of different methods, that the 3′ untranslated region (3′UTR) of subgroup II strains of cucumber mosaic Virus [CMV(II)] is related more closely to that of Tomato Aspermy Virus (TAV) than to those of CMV(I) strains. These results suggest that the CMV(II) 3′UTR arose by interspecific CMV/TAV recombination. The putative crossover is close to the 5′ end of the 3′UTR, at a recombination hot spot previously observed in short time-frame experiments. The CMV(II) strains show divergence from TAV at specific points along the 3′UTR that most probably indicate adaptive changes due to natural selection. Thus, for the large majority of CMV(II) strains examined, the 3′UTR has two discrete regions, W (nt 1902–1971) and Y (nt 2126–2184), that are more similar to the corresponding regions of TAV than to those of CMV(I) strains.
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a map of the diversity of rna3 recombinants appearing in plants infected with cucumber mosaic Virus and Tomato Aspermy Virus
Virology, 2005Co-Authors: Melissanne De Wispelaere, Stephane Gaubert, Severine Trouilloud, Christophe Belin, Mark TepferAbstract:Abstract In order to better understand the role of recombination in creating the diversity of viral genomes that is acted on by selection, we have studied in detail the population of recombinant RNA3 molecules occurring in tobacco plants coinfected with wild-type strains of cucumber mosaic Virus (CMV) and Tomato Aspermy Virus (TAV) under conditions of minimal selection pressure. Recombinant RNA3s were observed in 9.6% of the samples. Precise homologous recombination predominated since it was observed at 28 different sites, primarily in six hot spots. Imprecise homologous recombination was observed at two sites, particularly within a GU repeat in the 5′ noncoding region. Seven of the eight aberrant homologous recombination sites observed were clustered in the 3′ noncoding region. These results have implications on the role of recombination in host adaptation and Virus evolution. They also provide essential baseline information for understanding the potential epidemiological impact of recombination in transgenic plants expressing viral sequences.
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A novel strategy for creating recombinant infectious RNA Virus genomes.
Journal of Virological Methods, 2004Co-Authors: Isabelle Fernandez-delmond, Mark Tepfer, Melissanne De Wispelaere, Stephane Gaubert, Olivier Pierrugues, Laurent Guilbaud, Zoltán Divéki, Christian Godon, Mireille JacquemondAbstract:Reverse transcriptases with RNase H activity are particularly apt to switch templates and generate recombinant molecules in vitro. This property has been exploited for the first time to create a library of recombinant RNAs 3 between two strains of Cucumber mosaic Virus (CMV) or between CMV and Tomato Aspermy Virus (TAV), which share 75 and 63% sequence identity, respectively. The recombination events were almost entirely of the precise homologous type, and occurred at the same sites as those previously identified in co-infected plants, making it possible to use this strategy to create numerous cDNA fragments with crossovers similar to those occurring in vivo. Sub-cloning of recombinant fragments into an infectious full-length clone was accomplished by homologous recombination in yeast, alleviating the need for in vitro ligation at common restriction sites. Most of the recombinant genomes were infectious. Association of these two methods constitutes an efficient and practical means for generating numerous infectious viral genomes equivalent to ones that might arise by precise homologous recombination between two parental viral genomes in nature.
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Synthesis of (-)-strand RNA from the 3' untranslated region of plant viral genomes expressed in transgenic plants upon infection with related Viruses.
Journal of General Virology, 2000Co-Authors: Pierre Yves Teycheney, Katalin Salanki, Mireille Jacquemond, Ervin Balazs, Rachid Aaziz, Sylvie Dinant, Colette Tourneur, Mark TepferAbstract:When expressed in transgenic tobacco plants, transgene mRNA that includes the 3′ untranslated region (3′ UTR) of Lettuce mosaic Virus served as template for synthesis of complementary (−)-strand RNA following an infection by Tobacco etch Virus, Tobacco vein mottle Virus or Pepper mottle Virus, but not when infected with Cucumber mosaic Virus. Deletion of the 3′ UTR from the transgene abolished the synthesis of (−)-strand transcripts. Similar results were obtained in transgenic tobacco plants expressing mRNA that includes the RNA3 3′ UTR of Cucumber mosaic Virus when infected with Tomato Aspermy Virus. These results show that the viral RNA-dependent RNA polymerase of several potyViruses and Tomato Aspermy Virus have the ability to recognize heterologous 3′ UTRs when included in transgene mRNAs, and to use them as transcription promoters.
Peter Palukaitis - One of the best experts on this subject based on the ideXlab platform.
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the n terminal 12 amino acids of Tomato Aspermy Virus 2b protein function in infection and recombination
Journal of General Virology, 2011Co-Authors: Peter PalukaitisAbstract: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 not expressing 2b protein did not infect plants systemically. Chimeric Viruses expressing either the N-terminal 43 or 12 aa of the 2b protein infected both plant species systemically and facilitated CMV–TAV recombination, but induced mild symptoms and no symptoms in the infected plants, respectively. These data suggest that oligopeptides can have important functions in the biology of Viruses and prompt a re-examination of existing small ORFs in sequenced Virus genomes.
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Symptom induction and RNA silencing suppression by the cucumber mosaic Virus 2b protein.
Plant Signaling & Behavior, 2010Co-Authors: Mathew G. Lewsey, Peter Palukaitis, Inmaculada González, Natalia O. Kalinina, Tomas Canto, John P. CarrAbstract:The 2b protein encoded by Cucumber mosaic Virus (CMV) and other cucumoViruses is multifunctional, having roles in local and systemic Virus movement, symptom determination, evasion of defense mediated by salicylic acid, and in suppression of antiviral RNA silencing. It also perturbs silencing-mediated regulation of host transcripts, suggesting that another function of 2b protein is to manipulate host gene expression and physiology in a way that may aid the Virus. The 2b proteins encoded by the various cucumoViruses (CMV strains, as well as Tomato Aspermy Virus and Peanut stunt Virus) share conserved amino acid sequence domains, suggesting that these might determine specific functions of the protein. We analyzed the effect of mutations in these domains on functions of the 2b protein during viral infection. This revealed that binding of short RNAs, the key determinants of RNA silencing specificity, correlates with RNA silencing suppression activity. Two putative phosphorylation sites were found to be require...
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Cucumber Mosaic Virus 2b Protein Subcellular Targets and Interactions: Their Significance to RNA Silencing Suppressor Activity
Molecular Plant-microbe Interactions, 2010Co-Authors: Inmaculada González, Peter Palukaitis, Mathew G. Lewsey, Natalia O. Kalinina, John P. Carr, Llucia Martínez, Daria V. Rakitina, Félix A. Atencio, César Llave, Tomas CantoAbstract:The RNA silencing suppressor activity of the 2b protein of Cucumber mosaic Virus (CMV) has been variously attributed to its nuclear targeting, its interaction with and inhibition of Argonaute 1 (AGO1), or its ability to bind small RNAs in vitro. In addition, the 2b ortholog of Tomato Aspermy Virus forms aggregates and binds RNAs in vitro. We have further studied the relationships between CMV 2b protein silencing suppressor activity and its subcellular distribution, protein-protein interactions in vivo, and interactions with small interfering RNAs in vitro. To do this, we tagged the protein with fluorescent markers and showed that it retained suppressor activity. We showed that the 2b protein is present in the nucleolus and that it self-interacts and interacts with AGO1 and AGO4 in vivo. Using a battery of mutants, we showed that the putative nuclear localization signals and phosphorylation motif of the 2b protein are not required for self-interaction or for interaction with AGO proteins. The occurrence of...
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The cucumoVirus 2b gene drives selection of inter-viral recombinants affecting the crossover site, the acceptor RNA and the rate of selection
Nucleic Acids Research, 2007Co-Authors: Robert H Symons, Peter PalukaitisAbstract:RNA–RNA recombination is an important pathway in Virus evolution and has been described for many Viruses. However, the factors driving recombination or promoting the selection of recombinants are still unclear. Here, we show that the small movement protein (2b) was able to promote selection of RNA 1/2–RNA 3 recombinants within a chimeric Virus having RNAs 1 and 2 from cucumber mosaic Virus, and RNA 3 from the related Tomato Aspermy Virus, along with heterologous 2b genes. The source of the 2b also determined the selection of the acceptor RNA and the crossover site, as well as affecting the rate of selection of the recombinant RNAs. The nature of the RNA 3 also influenced the selection of the recombinant RNAs. A 163-nt tandem repeat in RNA 3 significantly affected the rate of selection of the recombinant RNA, while a single nucleotide within the repeat affected the crossover site. The recombination occurred in a non-random manner, involved no intermediates and probably was generated via a copy-choice mechanism during (+) strand RNA synthesis.
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The Conserved, 5′ Termini of RNAs 1 and 2 of Tomato Aspermy Virus are Dispensable for Infection but Affect Virulence
Virus Genes, 2005Co-Authors: Peter Palukaitis, Robert H SymonsAbstract:The 5′ terminus of each of the three genomic RNAs (RNAs 1, 2 and 3) of Tomato Aspermy Virus (TAV) begins with the sequence 5′-GUUU, which is also shared by a number of other Viruses. Mutagenic analyses showed that the 5′-GUUU sequence of RNAs 1 and 2 of TAV was dispensable for viral infection and did not prevent symptom induction. On the other hand, substitution of U at position 5 for G in RNA 1, but not RNA 2, induced veinal necrosis symptoms in Nicotiana glutinosa . The mutants constructed included insertion of UUU into the 5′-GUUU sequence of TAV RNAs 1 and/or 2. All RNA 2 mutants induced more severe symptoms than viral RNAs containing either mutated RNA 1 or most combinations of mutated RNAs 1 and 2. Some combinations of mutated RNAs 1 and 2 also induced veinal necrosis in N. glutinosa . Virulence was unrelated to the levels of viral RNA accumulation. Sequence analysis of progeny viral RNAs showed that only the mutant viral RNAs with a G to U substitution in RNA 1 and the deletion of the 5′-GUUU in both RNAs 1 and 2 were able to maintain the same sequence as the inoculum. The other mutants either reverted to the wildtype sequence or underwent further deletion or insertion. None of the constructed mutants were able to compete for accumulation with the wildtype Virus after co-inoculation to the plant species tested.
Katalin Salanki - One of the best experts on this subject based on the ideXlab platform.
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Identification a coat protein region of cucumber mosaic Virus (CMV) essential for long-distance movement in cucumber
Archives of Virology, 2011Co-Authors: Katalin Salanki, Ákos Gellért, László Kiss, Ervin BalazsAbstract: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. Introducing these mutations into the TAV CP was not sufficient for long-distance movement, indicating that this is not the sole region causing long-distance movement deficiency.
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Identification a coat protein region of cucumber mosaic Virus (CMV) essential for long-distance movement in cucumber
Archives of Virology, 2011Co-Authors: Katalin Salanki, Ákos Gellért, László Kiss, Ervin BalazsAbstract:Springer-Verlag 2011 Abstract 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 bB-bC loop that were essential for the CMV long-distance movement in cucumber. Introducing these mutations into the TAV CP was not sufficient for long-distance movement, indicating that this is not the sole region causing long-distance movement deficiency.
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Gazdanövénykört és betegségtüneteket meghatározó vírusgének analízise, különös tekintettel a cucumovírusokra = Analysis of the genetic determinants of cucumoviral host range and sympTomatology
2009Co-Authors: Katalin Salanki, Ákos Gellért, László KissAbstract:Novenyi virosok eseteben a gazdanovenykort es a kialakulo Virustuneteket szamos Virusgen befolyasolja. Gazdasagilag az egyik legjelentősebb Virusnemzetseg eseten, a cucumoVirusoknal kulonboző Virusgenek patologiai jelentőseget vizsgaltuk. A szisztemikus terjedesben szerept jatszo kopenyfeherje vizsgalata soran az uborka mozaik Virus (cucumber mosac Virus, CMV) kopenyfeherjejenek a virion felszinen lokalizalodo ot hurok regiojat paradicsom magtalansag Virus (Tomato Aspermy Virus, TAV) megfelelő regioira cserelve, majd pontmutansokat keszitve azonositottuk, hogy a cucumoVirusok szisztemikus mozgasaban a 'B-'C hurok harom aminosavanak van kulcsszerepe. A CMV-Ns izolatuma hiperszenzitiv reakciot (HR) indukal Nicotiana tabacum cv. Xanthi-nc es Nicotiana glutinosa novenyeken. A HR kivaltasanak genetikai determinansakent az 1a feherje 461 aminosavat azonositottuk, majd az elicitor funkciot molekularis modellezessel tervezett mutans Virusok felhasznalasaval vizsgaltuk. A josolt reszleges feherjeszerkezet felhasznalasaval elemeztuk a fertőzesi kiserletek eredmenyeit. A foldimogyoro satnyulas Virus (peanut stunt Virus, PSV) akac izolatumanak (PSV-Rp) teljes nukleinsav sorrendjet meghataroztuk. A PSV izolatumok homologia viszonyai es a rekombinacios vizsgalatok indokoltak egy uj, IV. PSV alcsoport kialakitasa. | In the case of plant Viruses symptoms and host range differences are affected by several different viral factors. We have analysed such viral determinants in the case of cucumoViruses inducing considerable harm to agriculture worldwide. To characterise the long-distance movement determinant of cucumoviral coat proteins (cp), 5 mutants were engineered into the Cucumber mosaic Virus (CMV) cp bearing the corresponding Tomato Aspermy Virus (TAV) loops exposed on the surface of the virion. Three amino acids of the 'B-'C loop of the CP were identified as critical determinants for long-distance movement of cucumoViruses. The Ns-strain of CMV induces a hypersensitive response (HR) on Nicotiana tabacum cv. Xanthi-nc and on Nicotiana glutinosa. The genetic determinant of the HR induction was localised to amino acid 461 of the 1a protein and the elicitor function was characterized with a series of mutants based on molecular modeling. We analysed the results in terms of a predicted partial protein structure. The complete nucleotide sequence of Peanut stunt Virus Robinia strain (PSV-Rp) was determined and compared to other PSV strains. Recombination breakpoint analysis revealed two recombination points on the RNA3. Based on our results we proposed to establish a forth PSV subgroup, and our work revealed that homologous recombination occurred in PSV evolution.
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Synthesis of (-)-strand RNA from the 3' untranslated region of plant viral genomes expressed in transgenic plants upon infection with related Viruses.
Journal of General Virology, 2000Co-Authors: Pierre Yves Teycheney, Katalin Salanki, Mireille Jacquemond, Ervin Balazs, Rachid Aaziz, Sylvie Dinant, Colette Tourneur, Mark TepferAbstract:When expressed in transgenic tobacco plants, transgene mRNA that includes the 3′ untranslated region (3′ UTR) of Lettuce mosaic Virus served as template for synthesis of complementary (−)-strand RNA following an infection by Tobacco etch Virus, Tobacco vein mottle Virus or Pepper mottle Virus, but not when infected with Cucumber mosaic Virus. Deletion of the 3′ UTR from the transgene abolished the synthesis of (−)-strand transcripts. Similar results were obtained in transgenic tobacco plants expressing mRNA that includes the RNA3 3′ UTR of Cucumber mosaic Virus when infected with Tomato Aspermy Virus. These results show that the viral RNA-dependent RNA polymerase of several potyViruses and Tomato Aspermy Virus have the ability to recognize heterologous 3′ UTRs when included in transgene mRNAs, and to use them as transcription promoters.
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biological properties of pseudorecombinant and recombinant strains created with cucumber mosaic Virus and Tomato Aspermy Virus
Journal of Virology, 1997Co-Authors: Katalin Salanki, Isabelle Carrere, Mireille Jacquemond, Ervin Balazs, Mark TepferAbstract:Cucumber mosaic Virus (CMV) and Tomato Aspermy Virus (TAV) are closely related cucumoViruses. We have made pseudorecombinant Viruses in which the RNAs 3 of these two Viruses have been exchanged and recombinant Viruses containing chimeric RNA 3 molecules, in which the coat proteins and the 3'-end regions of CMV and TAV have been exchanged, giving rise to recombinants designated RT3 and TR3. The replication properties and the cell-to-cell and long-distance movement patterns of these pseudorecombinant and recombinant Viruses were examined in different hosts. All the Viruses were able to replicate and accumulate RNA 4 in protoplasts. The pseudorecombinants and the R1R2RT3 recombinant infected tobacco systemically, but the R1R2TR3 recombinant was not detectable, even in the inoculated leaves. Comparison of the abilities of the Viruses to replicate in protoplasts and intact cucumber plants suggests that cell-to-cell movement factors are also encoded by RNAs 1 and/or 2. Major determinants of symptom severity in Nicotiana glutinosa are localized on the 3' part of RNA 3, and in Nicotiana benthamiana, more severe symptoms were observed with the T1T2R3 strain than with the others tested.
Enrique Moriones - One of the best experts on this subject based on the ideXlab platform.
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mapping helper Virus functions for cucumber mosaic Virus satellite rna with pseudorecombinants derived from cucumber mosaic and Tomato Aspermy Viruses
Virology, 1994Co-Authors: Enrique Moriones, Isabel Diaz, Aurora Fraile, Beatriz Fernandezcuartero, Xsef J Burgyn, Fernando GarciaarenalAbstract:Abstract P-TAV is a strain of Tomato Aspermy Virus (TAV) able to efficiently support the systemic accumulation of some (i.e., B2-satRNA) but not of other (i,e., Ix-satRNA) strains of the satellite RNA (satRNA) of cucumber mosaic Virus (CMV) in both tobacco and in Tomato. As reported for V-TAV, the failure to support the systemic accumulation of Ix-satRNA seems to be due to an inefficient support of its systemic movement. Pseudorecombinants obtained by the exchange of RNAs 1 + 2 between P-TAV and TrK7-CMV, an efficient helper for the systemic accumulation of Ix-satRNA, were assayed for their ability to support the accumulation of CMV-satRNAs in tobacco plants and protoplasts. Pseudorecombinants having RNAs 1 + 2 from CMV supported the systemic movement and accumulation of CMV-satRNA as efficiently as CMV, whereas pseudorecombinants having RNAs 1 + 2 from TAV supported the CMV-satRNA very poorly. Thus, the ability to support the systemic movement and accumulation of CMV-satRNA is determined primarily by RNAs 1 + 2 and not by RNA 3, which is presumed to encode movement functions in the cucumoViruses and only has a minor, modulating effect on the systemic accumulation of satRNA. This suggests that for systemic movement CMV-satRNA has to interact with (the gene products of) RNAs 1 and/or 2 or that these viral RNAs compete with the satRNA for interaction with the coat or other movement proteins.
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differential interactions among strains of Tomato Aspermy Virus and satellite rnas of cucumber mosaic Virus
Virology, 1992Co-Authors: Enrique Moriones, Isabel Diaz, Emilio Rodriguezcerezo, Aurora Fraile, Fernando GarciaarenalAbstract:Abstract Tomato and tobacco plants were inoculated with either of two strains of Tomato Aspermy Virus, 1-TAV or V-TAV, and each of six isolates of cucumber mosaic Virus satellite RNA (CMV-satRNA), B1, B2, B3, G, lx, or WL2. Ribonuclease protection assays, used to detect total satRNA and encapsidated satRNA, revealed that G-satRNA generated new satellite RNA not of the inoculated sequence. The other CMV-satRNAs were compared for their ability (1) to replicate, (2) to modulate symptoms, (3) to reduce TAV accumulation, and (4) to alter the extent of encapsidation of TAV genomic RNAs. The fraction of B2- and B3-satRNAs encapsidated was greater for 1-TAV than for WTAV, although spread and accumulation of the satRNA were similar for both helper Viruses. These results suggest that CMV-satRNA may spread in a nonencapsidated form. Accumulation of CMV-satRNA in systemically infected leaves was detected for all inoculum combinations except V-TAV and lx-satRNA, for which the satellite RNA increased only in protoplasts and inoculated leaves of tobacco or Tomato. In such inoculated leaves, lx-satRNA was not detected in capsids. Thus the effectiveness of the TAV helpers of CMV-satRNAs may be controlled in at least some instances by the extent of satRNA spread or encapsidation rather than by the efficiency of satRNA replication. In contrast to infections initiated by inoculation of CMV and CMV-satRNA, inoculation of 1-TAV or V-TAV and CMV-satRNA did not alter the relative amounts of viral genomic RNAs encapsidated or result in accumulation of large amounts of double-stranded satRNA.
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evolutionary relationships in the cucumoViruses nucleotide sequence of Tomato Aspermy Virus rna 1
Journal of General Virology, 1991Co-Authors: Juan J Bernal, Enrique Moriones, Fernando GarciaarenalAbstract:RNA 1 of the V strain of Tomato Aspermy Virus (TAV) consists of 3410 nucleotides and contains one open reading frame (ORF) of 2982 nucleotides, resembling RNA 1 of cucumber mosaic Virus (CMV) strains Q and Fny (68% and 66% identical, respectively) and of brome mosaic Virus (BMV) (41% identical). In comparisons between amino acid sequences, three conserved regions (N-terminal, C-terminal and central) between TAV and each CMV were found. The N- and C-terminal regions were also conserved with BMV, and contained, respectively, consensus motifs for methyltransferases and for nucleic acid helicases. The 5′ and 3′ non-coding sequences were highly similar to those of TAV RNA 2. When the sequences for the genomic RNAs of the V and C strains of TAV, and of their encoded products, are compared with those reported for CMV strains representing either subgroup I (Fny-CMV) or subgroup II (Q-CMV) of CMV, it was found that the different Virus-encoded proteins are conserved differently between these three Viruses. Also, the divergence between TAV and both CMV subgroups has proceeded at different rates for the different ORFs. On the whole, the divergence between TAV and CMV is of the same order as that found between CMV subgroups I and II, which suggests that TAV, Q-CMV and Fny-CMV could be considered as representing three equivalent subgroups of a taxonomic entity.
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nucleotide sequence of Tomato Aspermy Virus rna 2
Journal of General Virology, 1991Co-Authors: Enrique Moriones, Marilyn J Roossinck, Fernando GarciaarenalAbstract:RNA 2 of the V strain of Tomato Aspermy Virus (TAV) consists of 3074 nucleotides and contains one open reading frame of 2487 nucleotides. Thus, it resembles RNA 2 of cucumber mosaic Virus (CMV) strains Q and Fny (62% identical to both), brome mosaic Virus (42% identical) and cowpea chlorotic mottle Virus (40% identical). In comparisons between amino acid sequences, three different regions of similarity could be distinguished. These were the central part (amino acids 224 to 757 for V-TAV), which was most similar among the four Viruses, and the N and C ends; sequences conserved among RNA polymerase species were found in the C half of the central part. Hydrophobicity patterns, and distributions of acidic and basic amino acids in the proteins encoded by V-TAV RNA 2, Q-CMV RNA 2 and Fny-CMV RNA 2 were very similar except at the extreme ends of the molecules. Structures that have been reported to act as regulatory signals for minus- and plus-strand synthesis were found in the 5′ and 3′ non-coding regions of the RNA.