Tesis sobre el tema "Cucumber mosaic virus Genetics"
Siga este enlace para ver otros tipos de publicaciones sobre el tema: Cucumber mosaic virus Genetics.
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Cucumber mosaic virus Genetics".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Wahyuni, Wiwiek Sri. "Variation among cucumber mosaic virus (CMV) isolates and their interaction with plants". Title page, contents and summary only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phw137.pdf.
Resumen
Includes appendix containing journal publications co-authored by the author. Includes bibliographical references (leaves 130-151). Eighteen strains of Cucumber mosaic virus, including forteen from Australia, two from the USA, and two from Japan were used in this study.
2
Afsharifar, Alireza. "Characterisation of minor RNAs associated with plants infected with cucumber mosaic virus". Title page, table of contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09pha2584.pdf.
Resumen
Bibliography: leaves 127-138. This thesis studies the minor double stranded RNAs (dsRNA) and single stranded RNAs (ssRNA) which are consistently associated with plants infected with Q strain of cucumber mosaic virus (Q-CMV). The investigations are focused on the structural elucidation of new RNAs which have been observed in single stranded and double stranded RNA profiles of Q strain of CMV.
3
Williams, Rhys Harold Verdon George. "Further studies on the structure and function of the cucumber mosaic virus genome : a thesis submitted to the University of Adelaide, South Australia for the degree of Doctor of Philosophy". 1988, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phw7261.pdf.
4
Chen, Baoshan. "Encapsidation of nucleic acids by cucumovirus coat proteins /". Title page, contents and summary only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phc5183.pdf.
5
Yang, Rongchang. "Towards genetic engineering cucumber mosaic virus (CMV) resistance in lupins". Thesis, Yang, Rongchang ORCID: 0000-0003-2563-2015 (2000) Towards genetic engineering cucumber mosaic virus (CMV) resistance in lupins. PhD thesis, Murdoch University, 2000. https://researchrepository.murdoch.edu.au/id/eprint/41568/.
Resumen
Cucumber mosaic virus (CMV) is a serious pathogen of many economically important crops. In Western Australia (WA), CMV is a serious disease of narrow-leafed lupin, Lupinus angustifolius, which is the main grain legume crop. There is no known natural resistance genes to CMV have been identified .in narrow-leafed lupin germplasm that can be transferred to new cultivars using classical breeding techniques. The aim of this project was to develop a series of molecular resistance constructs and to apply them to produce pathogen-derived resistance to CMV in narrow-leafed lupin. A total of nine different CMV resistance gene constructs were developed. Eight constructs were based on the movement protein (MP), coat protein (CP) and replicase (Rep) genes of the WA subgroup II CMV-LY isolate originally obtained from infected narrow-leafed lupin, and one was based on the CP gene of a WA subgroup I CMV isolate from banana.
The gene constructs were cloned into the plant binary vectors pYR2 and pART27/7 driven by promoters from subterranean clover stunt virus (pPLEX) and cauliflower mosaic virus (CaMV 35S) and transferred into Agrobacterium (strain: AGL0). The constructs were used to transform Nicotiana benthamiana and narrow-leafed lupin with Basta as the selectable agent. For N. benthamiana a total of 1,120 explants were cocultivated with A. tumefaciens containing the pART27/7 resistance gene constructs (80 explants per construct). Following selection in culture, 16 putative transformants for each construct were transferred to the glasshouse for seed production and analysis. PCR analysis of T1 plants indicated that transformation had been successfully achieved for each of the resistance gene constructs. Transgenic plants were challenged with CMV and susceptibility or resistance was analysed by symptom development and ELISA. The results showed that some transgenic N. benthamiana plants that contained the Repm1 gene (defective CMV-LY ORF2a) were resistant to CMV-LY. In twenty-two PCR positive T₁ plants, 7 showed immunity, 12 were partially resistant, and 3 were susceptible to CMV-LY infection. In contrast, the antisense defective CMV-LY RNA 2 construct (Repm2) did not give good resistance to CMV-LY. Three of 12 T₁ plants with this construct were partially resistant (or had delayed symptoms) and the other nine were susceptible. Transgenic T1 plants containing a CMV-LY MP sense gene (MP1) showed limited resistance to CMV-LY. Two of 12 plants showed partial resistance (delayed symptoms) and two exhibited a recovery phenotype. The development of disease symptoms in the susceptible plants was faster than that in other transgenic and nontransgenic plants. Plants with the MPS transgene (untranslatable CMV-LY MP gene) showed some resistance to CMV-LY. One of 11 plants was highly resistant and three were partially resistant to CMV-LY. Three different versions of CMV-LY CP gene (CPI, CP3 and CP4) were transformed into N. benthamiana and the T₁ plants were challenged with CMV-LY. The level of resistance varied in transgenic plants depending on the CP genes present. Although a limited number of transgenic plants have been tested so far, it appears that plants containing CP4-1 show more effective resistance to CMV than transgenic plants with either CPl-1 or CP3-1. This result appears to be the first example of the use of a mutated CP gene that is longer than the wild type gene product (12 additional amino acids) and confers resistance to CMV.
For narrow-leafed lupin, 12,411 explants were subjected to meristem inoculation and cocultivated with A. tumefaciens containing a replicase construct (pYRRepm1) and 3,134 explants with a movement protein construct (pYRMPS1). One hundred and sixty one independent transformants survived in vitro selection and were grafted onto compatible nontransgenic rootstocks. Fifty nine plants survived the grafting process and were transferred to the glasshouse for seed production. PCR analysis of the 59 putative transgenic lines (T0) identified 7 plants positive for the pYRRepml gene and 15 for the p YRMPS 1 gene.
The complete genomic sequence of the CMV-LY isolate was also determined. The RNA1 molecule was determined to be 3,391 nucleotides (nt) in length and is predicted to contain a 5' untranslated region (UTR) of 95 nucleotides, a single open-reading frame (ORF) of 992 amino acids and a 3' UTR of 317 nt. The RNA2 molecule is 3,038 nt long and is predicted to contain a 5' UTR of 92 nt, two ORFs of 841 and 100 amino acids (ORF2a and ORF2b, respectively) and a 3' UTR of 423 nt. The RNA3 molecule is 2,003 nt long and is predicted to contain a 5' UTR of 96 nt, two ORFs of 279 and 218 amino acids (ORF3a and ORF3b, respectively) and a 3' UTR of 322 nt. Nucleotide comparisons of RNAs1-3 indicate that the LY isolate shares between 70-78% and 98-99% homology to subgroup I and subgroup II isolates, respectively. Similarly, ORFla shares 84-85% and 99% identity, ORF2a 81-84% and 94-96% identity, ORF2b 46-56% and 95-96% identity, ORF3a 82-84% and 99% identity, and ORF3b 81-83% and 99% identity. The sequence data clearly shows that there is a high degree of nucleotide and amino acid sequence homology between the CMV-LY isolate and other CMV subgroup II strains. The sequence data confirms that the LY isolate belongs to CMV subgroup II.
6
Geering, Andrew D. W. "The epidemiology of cucumber mosaic virus in narrow-leafed lupins (Lupinus angustifolius) in South Australia". Title page, table of contents and summary only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phg298.pdf.
7
Balcı, Evrim Doğanlar Sami. "Genetic characterization of cucumber mosaic virus(CMV)resistance in tomato and pepper". [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/biyoloji/T000388.pdf.
8
Tamisier, Lucie. "Adaptation des populations virales aux résistances variétales et exploitation des ressources génétiques des plantes pour contrôler cette adaptation". Thesis, Avignon, 2017. http://www.theses.fr/2017AVIG0696/document.
Resumen
L’utilisation de variétés de plantes porteuses de gènes majeurs de résistance a longtemps été une solution privilégiée pour lutter contre les maladies des plantes. Cependant, la capacité des agents pathogènes à s’adapter à ces variétés après seulement quelques années de culture rend nécessaire la recherche de résistances à la fois efficaces et durables. Les objectifs de cette thèse étaient (i) d’identifier chez la plante des régions génomiques contraignant l’évolution des agents pathogènes en induisant des effets de dérive génétique et (ii) d’étudier l’impact des forces évolutives induites par la plante sur la capacité d’adaptation des pathogènes aux résistances variétales, l’ambition étant par la suite d’employer au mieux ces forces pour limiter l’évolution des pathogènes. Le pathosystème piment (Capsicum annuum) – PVY (Potato virus Y) a été principalement utilisé pour mener ces travaux de recherche. Afin de répondre au premier objectif, une cartographie de QTL (quantitative trait loci) sur une population biparentale de piment et une étude de génétique d’association sur une core-collection de piments ont été réalisées. Ces deux approches ont permis de mettre en évidence des régions génomiques sur les chromosomes 6, 7 et 12 impliquées dans le contrôle de la taille efficace des populations virales lors de l’étape d’inoculation du virus dans la plante. Certains de ces QTL ont montré une action vis-à-vis du PVY et du CMV (Cucumber mosaic virus) tandis que d’autres se sont révélés être spécifiques d’une seule espèce virale. Par ailleurs,le QTL détecté sur le chromosome 6 co-localise avec un QTL précédemment identifié comme contrôlant l’accumulation virale et interagissant avec un QTL affectant la fréquence de contournement d’un gène majeur de résistance. Pour répondre au second objectif, une analyse de la corrélation entre l’intensité des forces évolutives induites par la plante et une estimation expérimentale de la durabilité du gène majeur a été réalisée. De l’évolution expérimentale de populations de PVY sur des plantes induisant des effets de dérive génétique, de sélection et d’accumulation virale contrastés a également été effectuée. Ces deux études ont démontré qu’une plante induisant une forte dérive génétique associée à une réduction de l’accumulation virale permettait de contraindre l’évolution des populations virales, voire d’entraîner leur extinction. Ces résultats ouvrent de nouvelles perspectives pour le déploiement de déterminants génétiques de la plante qui influenceraient directement le potentiel évolutif du pathogène et permettraient de préserver la durabilité des gènes majeurs de résistancePlants carrying major resistance genes have been widely used to fight against diseases. However, the pathogensability to overcome the resistance after a few years of usage requires the search for efficient and durable resistances.The objectives of this thesis were (i) to identify plant genomic regions limiting pathogen evolution by inducinggenetic drift effects and (ii) to study the impact of the evolutionary forces imposed by the plant on the pathogenability to adapt to resistance, the goal being to further use these forces to limit pathogen evolution. The pepper(Capsicum annuum) – PVY (Potato virus Y) pathosystem has been mainly used to conduct these researches.Regarding the first objective, quantitative trait loci (QTL) were mapped on a biparental pepper population andthrough genome-wide association on a pepper core-collection. These approaches have allowed the detection ofgenomic regions on chromosomes 6, 7 and 12 controlling viral effective population size during the inoculationstep. Some of these QTLs were common to PVY and CMV (Cucumber mosaic virus) while other were virusspecific.Moreover, the QTL detected on chromosome 6 colocalizes with a previously identified QTL controllingPVY accumulation and interacting with a QTL affecting the breakdown frequency of a major resistance gene.Regarding the second objective, a correlation analysis between the evolutionary forces imposed by the plant andan experimental estimation of the durability of a major resistance gene has been done. Experimental evolution ofPVY populations on plants contrasted for the levels of genetic drift, selection and virus accumulation they imposedhas also been performed. Both studies demonstrated that a plant inducing a strong genetic drift combined to areduction in virus accumulation limits virus evolution and could even lead to the extinction of the virus population.These results open new perspectives to deploy plant genetic factors directly controlling pathogen evolutionarypotential and could help to preserve the durability of major resistance genes
9
McQuillin, Andrew. "Aspects of cucumber mosaic virus replication". Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321682.
10
Tungadi, Trisna Dewi. "Cucumber mosaic virus modifies plant-aphid interactions". Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708288.
11
Mayers, Carl Nicholas. "Cucumber mosaic virus : defence and counter-defence". Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621673.
12
Knox, Elizabeth. "Mixed infections of maize dwarf mosaic virus and cucumber mosaic virus in maize". Master's thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/21898.
Resumen
Bibliography : pages 218-230.Maize plants collected in three geographically distinct regions of South Africa were found to be doubly infected with maize dwarf mosaic (MDMV) and cucumber mosaic virus (CMV). A mixed infection of these two viruses could be maintained in maize plants grown under laboratory conditions. The possibility of synergism or of an interference mechanism between MDMV and CMV in dual infections was investigated and it was found that prior infection with CMV interfered with subsequent infection by MDMV. MDMV and CMV were shown to be non-persistently transmitted by Myzus persicae, Rhopalosiphum padi and Rhopalosipbum maidis aphids. Protoplasts were isolated from maize seedlings and could be viably maintained for up to 66 hours. The maize protoplasts were infected with CMV and MDMV either singly, or together as a mixed inoculum. Infection curves for each virus were plotted. The presence of CMV in a mixed inoculum appeared to prevent infection of the protoplasts by MDMV. Protoplasts were isolated from plants systemically infected with CMV and/or MDMV. Superinfection of protoplasts prepared from CMV infected seedlings with MDMV was not possible. As a possible vehicle for virus infection of protoplasts liposomes were produced. Initially fluorescent dyes were incorporated in them. These were fused to the maize protoplasts. Attempts were made to encapsulate virus particles in the liposomes and fuse them to maize protoplasts but this was not successful.
13
Westwood, Jack Henry. "Cucumber mosaic virus infection and plant-aphid interactions". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608811.
14
Burman, Alison Jane. "Molecular studies of the cucumber mosaic virus movement protein". Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309317.
15
Soards, Avril Jacqueline. "The Cucumber mosaic virus 2b protein : influences on the plant-virus interaction". Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619971.
16
Thomas, C. M. "Cauliflower mosaic virus DNA replication". Thesis, Bucks New University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374828.
17
Lupuwana, Pumezo. "Identification and characterisation of South African strains of cucumber mosaic virus". Master's thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/21901.
Resumen
Bibliography: pages 107-112.This project was then aimed at finding naturally occurring isolates of CMV, characterising them, producing much needed antisera and to use such antisera in a comparison with other well characterised strains by the use of new contemporary sensitive serological techniques.
18
Hackland, Andrew F. "The development of transgenic plants resistant to cucumber mosaic virus and tobacco necrosis virus". Doctoral thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/21411.
Resumen
Bibliography: pages 108-128.Cucumber mosaic virus (CMV) and tobacco necrosis virus (TN V) often occur in mixed virus infections in South Africa. Both viruses are of economic importance because of their world-wide distribution, extensive host range and their effects on yields of agriculturally important crop plants. The complete cDNA sequences of CMV-Wemmershoek (CMV-Wem) coat protein (CP) and TNV-F5P CP genes were cloned and subjected to sequence analysis. CMV-Wem is closely related to CMV-WL and CMV-Q, and therefore falls into CMV subgroup II. Similar analysis showed that TNV-F5P is closely related to TNV-A. By characterizing and sequencing these clones the authenticity of the CMV and TNV CP genes was also determined, prior to sub cloning into the appropriate vectors for expression in E. coli and tobacco. Constructs containing both the full-length CP genes of CMV-Wem and TNV-F5P were subcloned in frame with the malE gene, encoding the maltose binding protein (MBP), in the IPTG-inducible pMALTM vector system, and expressed in E. coli. Through immunological detection the authenticity of both CPs was confirmed. The CMV CP translation product expressed in E.coli was used as an antigen to raise antiserum free from contaminating plant host-specific antibodies. The CP genes of both viruses were individually cloned in both orientations (sense and antisense) in Agrobacterium tumefaciens Ti-plasmid-based binary and cointegrate vectors. The study was then extended to include engineering doubly transgenic plants. In order to determine whether the full-length CP is required to mediate virus resistance, a truncated form of the TNV CP was generated by deleting 83 amino acids from the C-terminus. Transgenic Nicotiana tabacum cv Petit Havana SRl plants containing one of a number of different forms of CMV and TNV CP nucleotide sequence were generated. In whole plant studies, mechanical inoculation of Ro lines with CMV-Wem resulted in more than 50% of the CMV CP-sense (CP+) and CP-antisense plants not developing visible systemic disease symptoms. In both the CMV CP+ and doubly transgenic plants CMV-Wem accumulation was delayed, but virus was found to accumulate in the inoculated leaves over time. The CMV CP+ lines showed excellent protection against CMV-Q, but showed only a delay in symptom production when inoculated with CMV -Y, from subgroup I.
19
Ziebell, Heiko. "Investigating the mechanism(s) underlying cross-protection of cucumber mosaic virus strains". Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613299.
20
Guiu, Aragonés Cèlia. "Study of Cucumber mosaic virus infection in the resistant melon accession PI 161375". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/284908.
Resumen
L’accessió exòtica de meló PI 161375 presenta una barreja de resistència qualitativa i quantitativa front a la infecció per CMV depenent de la soca. Anteriorment s’ha descrit la presencia del gen recessiu de resistència cmv1 situat en el grup de lligament XII, i que conferia resistència total només a algunes soques de CMV (Essafi et al., 2009). En aquesta tesi hem ampliat els coneixements sobre la resistència determinada pel gen cmv1 present en meló i hem obtingut la seqüència i els clons infectius de la soca M6. Aquesta tesi ha estat estructurada en tres capítols.
En el primer capítol vam analitzar la resistència conferida pel gen cmv1 en 11 soques de CMV del subgrup I i II. Els resultats van indicar que cmv1 conferia resistència total a les soques del subgrup II però no a les del subgrup I. Mitjançant l’ús dels clons infectius de les soques CMV-LS (subgrup II) i CMV-FNY (subgrup I) vam fer combinacions entre els RNAs d’ambdues soques podent localitzar el determinant de virulència en el RNA3. Virus quimèrics entre FNY i LS van indicar-nos que el determinant de virulència estava en els 209 aminoàcids de l’extrem N-terminal de la proteïna de moviment. Mitjançant mutagènesi dirigida vàrem identificar una combinació de 4 posicions específiques que confereixen a LS l’habilitat de sobrepassar la resistència conferida pel gen cmv1 quan els substituïm pels residus corresponents de la soca FNY.
El segon capítol tracta de la caracterització de la resistència conferida pel gen cmv1. La soca CMV-LS és capaç de replicar-se i de moure’s cèl·lula a cèl·lula en la fulla inoculada de la línia resistent. No obstant, LS és incapaç d’envair el floema ja que no hem pogut detectar virus en el floema de la línia resistent. Mitjançant immunomarcatge de CMV amb or col·loïdal hem identificat el límit entre cèl·lules de la beina (BS) i parènquima vascular (VP) o cèl·lules acompanyants (IC) com a barrera que impedeix la infecció sistèmica en la línia portadora del gen cmv1. Amb els resultats obtinguts hem demostrat que la resistència determinada pel gen cmv1 interromp l’entrada del virus al sistema vascular, impedint així una infecció sistèmica.
En el tercer capítol vam obtenir la seqüència de la soca CMV-M6 i vam generar clons moleculars capaços d’infectar sistèmicament N. benthamiana i meló.La accesión exótica de melón PI 161375 presenta una mezcla de resistencia cualitativa y cuantitativa frente a la infección por CMV, dependiendo de la cepa. Anteriormente se describió en nuestro laboratorio la presencia del gen recesivo de resistencia cmv1 situado en el grupo de ligamiento XII, y que confería resistencia total sólo a algunas cepas de CMV (Essafi et al., 2009). En esta tesis hemos ampliado los conocimientos sobre la resistencia mediada por el gen cmv1 presente en melón y hemos obtenido la secuencia y los clones infectivos de la cepa M6. La tesis ha sido estructurada en tres capítulos. En el primer capítulo analizamos la resistencia conferida por el gen cmv1 en 11 cepas de CMV del subgrupo I y II. Los resultados indicaron que cmv1 confería resistencia total a las cepas del subgrupo II pero no a las del subgrupo I. Mediante el uso de los clones infecciosos de las cepas CMV-LS (subgrupo II) y CMV-FNY (subgrupo I) hicimos combinaciones entre los RNAs de ambas cepas, pudiendo localizar el determinante de virulencia en el RNA3. Quimeras entre FNY y LS indicaron que el determinante de virulencia estaba en los 209 aminoácidos del extremo N-terminal de la proteína de movimiento (MP). Mediante mutagénesis dirigida identificamos una combinación de 4 posiciones específicas que confieren a LS la habilidad de sobrepasar la resistencia mediada por cmv1 cuando las sustituimos por los residuos correspondientes de la cepa FNY. El segundo capítulo trata de la caracterización de la resistencia conferida por el gen cmv1. La cepa CMV-LS es capaz de replicarse y moverse célula a célula en la hoja inoculada de la línea resistente. No obstante, LS es incapaz de invadir el floema ya que no hemos podido detectar virus en el floema de la línea resistente. Mediante inmunomarcaje de CMV con oro coloidal hemos identificado el límite entre células de la vaina (BS) y parénquima vascular (VP) o células acompañantes (IC) como barrera que impide la infección sistémica en la línea portadora del gen cmv1. Con los resultados obtenidos hemos demostrado que la resistencia determinada por el gen cmv1 interrumpe la entrada del virus al sistema vascular, impidiendo así una infección sistémica. En el tercer capítulo hemos obtenido la secuencia de la cepa CMV-M6 y generado clones moleculares capaces de infectar sistémicamente N. benthamiana y melón.
The exotic melon accession PI 161375 shows a complex mixture of qualitative and quantitative resistance to Cucumber mosaic virus (CMV) infection, depending on the strain. Previously, the presence of a recessive gene (cmv1) in the linkage group XII conferring total resistance to a set of CMV strains was reported in our laboratory (Essafi et al., 2009). In this thesis we have extended the knowledge about the cmv1-mediated resistance present in melon and have obtained the sequence of the strain CMV-M6 and its infectious clones. This thesis is divided in three chapters. In the first chapter, we have analysed the cmv1-mediated resistance in 11 strains of CMV from subgroup I and II and have established that cmv1 confers total resistance only to strains of subgroup II. Using infectious clones of strains CMV-LS (subgroup II) and CMV-FNY (subgroup I) we have made combinations between RNAs of both strains showing that the determinant of the virulence is located in RNA3. Chimaeras between CMV-FNY and CMV-LS showed that the determinant of virulence is in the N-terminal 209 amino acids of the movement protein (MP). By directed mutagenesis, we identified a combination of four specific positions that confer to LS the ability to overcome cmv1-mediated resistance when exchanged for the corresponding FNY residues. In the second chapter, we have characterized the resistance mediated by cmv1. The strain CMV-LS is able to replicate and move cell to cell in the inoculated leaf of the resistant line. However, it is not able to invade the sieve elements since it has not been detected in the phloem of the resistant line. By immunogold labelling of CMV particles we have identified that the boundary between bundle sheath cells (BS) and vascular parenchyma (VP) or intermediary cells (IC) impedes the systemic infection in the resistant line. Altogether, our results demonstrate that the resistance determined by cmv1 involves interruption of the virus entry into the vascular system and therefore, inability to develop a systemic infection. In the third chapter, we have obtained the sequence of CMV-M6 strain and generated infectious clones able to infect systemically N. benthamiana and melon.
21
Masiri, Jongkit Murphy John F. "The nature of cucumber mosaic virus-induced symptoms in bell pepper (Capsicum annuum L.)". Auburn, Ala., 2009. http://hdl.handle.net/10415/1977.
22
Dias, Paulo Rogério Parente [UNESP]. "Caracterização de isolados e reação de Capsicum spp. ao Cucumber mosaic virus (CMV)". Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/105424.
Resumen
Made available in DSpace on 2014-06-11T19:35:00Z (GMT). No. of bitstreams: 0
Previous issue date: 2004-11-09Bitstream added on 2014-06-13T19:05:02Z : No. of bitstreams: 1
dias_prp_dr_botfca.pdf: 1303201 bytes, checksum: ff13b531a76b1d9405f4151a52ea6f09 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
Cucumber mosaic virus (CMV), uma espécie do gênero Cucumovirus, é um dos mais importantes vírus que infecta pimentão, causando prejuízos consideráveis na produção em todo o mundo. Quando da infecção precoce, em geral, ambas a qualidade e a quantidade de frutos produzidos são afetados. O vírus apresenta inúmeras estirpes capazes de infectar pimentão, diferindo na expressão dos sintomas. CMV pode infectar mais de 865 espécies de plantas, incluindo ervas daninhas, sendo transmitido por diversas espécies de afídeos de maneira não circulativa. Inseticidas são ineficazes para prevenir a disseminação da doença em virtude da forma de transmissão do vetor. No presente trabalho, verificou-se que o CMV foi o principal vírus identificado em campo. Vinte e três isolados de Capsicum spp. foram purificados biologicamente e caracterizados através de análises sorológica, biológica e molecular. Todos os 23 isolados da coleção foram classificados no subgrupo I do CMV, induzindo mosaico sistêmico, redução do desenvolvimento vegetativo e deformação foliar em Nicotiana glutinosa e Nicotiana tabacum 'Havana 425', diferindo apenas na intensidade de sintomas. Somente 8 isolados foram capazes de causar mosaico em Vigna unguiculata. Amplificação combinada com clivagem pela enzima Msp I foi eficiente para distinguir os subgrupos do CMV, resultando em banda de 500 pb somente para a amostra-controle do CMV II, dando origem a 3 fragmentos com 190, 150 e 120 pb, enquanto todos os outros isolados permaneceram com 488 pb e sem clivagem, correspondendo ao CMV-I. Não foi detectado RNA satélite em nenhum isolado do campo. A reação ao CMV de cultivares e híbridos comerciais de pimentão é desconhecida, mas tudo indica serem susceptíveis... .
Cucumber mosaic virus (CMV), a species of the genus Cucumovirus, is one of the most important virus that infect pepper, causing notable losses in pepper production worldwide. With early infection, in general, both quality and quantity of fruit produced will be affected. The virus exists as a number of strains capable of infecting pepper, differing in symptom expression. CMV can infect more than 865 plant species including many weed species and it is transmitted by many aphid species in a non-circulative manner, meaning that insecticides cannot prevent the spread of this disease. At this work, the CMV was the main virus identified in the field. Twenty-three CMV isolates from Capsicum spp. were biologically purified and characterized for serological, biological and molecular analysis. All 23 isolates from collection were found to belong to subgroup I. All isolates caused systemic mosaic, reduction of vegetative development and deformation in the leaf in N. glutinosa and N. tabacum 'Havana 425', differing in symptom intensity. Only 8 isolates were able to cause systemic mosaic in V. unguiculata. Amplification combined with Msp I cleavage was efficient to distinguish the CMV subgroups. This process resulted in a 500 pb for the CMV II control only, giving origin to three fragment with 190, 150 and 120pb, while all other isolates remained uncleaved with 488 pb, corresponding to the CMV-I isolates. It was not detect RNA satellite in a field isolates. Pepper comercial cultivars and hybrids reaction to CMV is unknowledge, but it seems to be susceptible. The identification of cultivated varieties or wild relatives of pepper that are better able to fend off attack by viral pathogens such as CMV is a critical first step towards developing resistant commercial varieties.
23
Dias, Paulo Rogério Parente 1973. "Caracterização de isolados e reação de Capsicum spp. ao Cucumber mosaic virus (CMV) /". Botucatu : [s.n.], 2004. http://hdl.handle.net/11449/105424.
Resumen
Orientador: Marcelo Agenor PavanBanca: Norberto da Silva
Banca: Renate Krause Sakate
Banca: Romulo Fujito Kobori
Banca: Cyro Paulino da Costa
Resumo: Cucumber mosaic virus (CMV), uma espécie do gênero Cucumovirus, é um dos mais importantes vírus que infecta pimentão, causando prejuízos consideráveis na produção em todo o mundo. Quando da infecção precoce, em geral, ambas a qualidade e a quantidade de frutos produzidos são afetados. O vírus apresenta inúmeras estirpes capazes de infectar pimentão, diferindo na expressão dos sintomas. CMV pode infectar mais de 865 espécies de plantas, incluindo ervas daninhas, sendo transmitido por diversas espécies de afídeos de maneira não circulativa. Inseticidas são ineficazes para prevenir a disseminação da doença em virtude da forma de transmissão do vetor. No presente trabalho, verificou-se que o CMV foi o principal vírus identificado em campo. Vinte e três isolados de Capsicum spp. foram purificados biologicamente e caracterizados através de análises sorológica, biológica e molecular. Todos os 23 isolados da coleção foram classificados no subgrupo I do CMV, induzindo mosaico sistêmico, redução do desenvolvimento vegetativo e deformação foliar em Nicotiana glutinosa e Nicotiana tabacum 'Havana 425', diferindo apenas na intensidade de sintomas. Somente 8 isolados foram capazes de causar mosaico em Vigna unguiculata. Amplificação combinada com clivagem pela enzima Msp I foi eficiente para distinguir os subgrupos do CMV, resultando em banda de 500 pb somente para a amostra-controle do CMV II, dando origem a 3 fragmentos com 190, 150 e 120 pb, enquanto todos os outros isolados permaneceram com 488 pb e sem clivagem, correspondendo ao CMV-I. Não foi detectado RNA satélite em nenhum isolado do campo. A reação ao CMV de cultivares e híbridos comerciais de pimentão é desconhecida, mas tudo indica serem susceptíveis... (Resumo completo, clicar acesso eletrônico abaixo).
Abstract: Cucumber mosaic virus (CMV), a species of the genus Cucumovirus, is one of the most important virus that infect pepper, causing notable losses in pepper production worldwide. With early infection, in general, both quality and quantity of fruit produced will be affected. The virus exists as a number of strains capable of infecting pepper, differing in symptom expression. CMV can infect more than 865 plant species including many weed species and it is transmitted by many aphid species in a non-circulative manner, meaning that insecticides cannot prevent the spread of this disease. At this work, the CMV was the main virus identified in the field. Twenty-three CMV isolates from Capsicum spp. were biologically purified and characterized for serological, biological and molecular analysis. All 23 isolates from collection were found to belong to subgroup I. All isolates caused systemic mosaic, reduction of vegetative development and deformation in the leaf in N. glutinosa and N. tabacum 'Havana 425', differing in symptom intensity. Only 8 isolates were able to cause systemic mosaic in V. unguiculata. Amplification combined with Msp I cleavage was efficient to distinguish the CMV subgroups. This process resulted in a 500 pb for the CMV II control only, giving origin to three fragment with 190, 150 and 120pb, while all other isolates remained uncleaved with 488 pb, corresponding to the CMV-I isolates. It was not detect RNA satellite in a field isolates. Pepper comercial cultivars and hybrids reaction to CMV is unknowledge, but it seems to be susceptible. The identification of cultivated varieties or wild relatives of pepper that are better able to fend off attack by viral pathogens such as CMV is a critical first step towards developing resistant commercial varieties.
Doutor
24
Turner, David Richard. "Protein-RNA interactions in tobacco mosaic virus assembly". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328799.
25
Cartwirght, Ewen James. "Barley mild mosaic virus : deletions, duplication and transmission". Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285557.
26
Chen, Pengyin. "Genetics of reactions to soybean mosaic virus in soybean". Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54781.
Resumen
The genetic interactions among 9 soybean [Glycine max (L.) Merr.] cultivars and 6 strains of soybean mosaic virus (SMV) were investigated. The objectives were to identify genes and/or alleles conditioning resistant and necrotic reactions to SMV and to determine the genetic relationships among resistance genes from cultivars exhibiting differential responses to the SMV strains.
Seven SMV-resistant (R) cultivars (‘PI 486355’, ‘Suweon 97’, ‘PI 96983’, ‘Ogden’, ‘York’, ‘Marshall’, and ‘Kwanggyo’) were crossed in all combinations among each other and with susceptible (S) cultivars ‘Essex’ and ‘Lee 68’. F₂ populations and F₂-derived F₃ lines were inoculated in field with the SMV type strain Gl and in the greenhouse with the virulent strains G4, G5, G6, G7, and G7A.
All F₂ populations from R x S and necrotic (N) x S crosses having PI 96983, Ogden, York, Marshall, and Kwanggyo as either resistant or necrotic parents segregated 3R:1S and 3N:1S, respectively. F₂-derived F₃ progenies from R x S crosses exhibited an F₂ genotypic ratio of 1 homogeneous R : 2 segregating (3R:1S) : l homogeneous S. The results indicate that each of these five resistant parents has a single, dominant or partially dominant gene conditioning the resistant and necrotic reactions to SMV. No segregation for SMV reaction was evident in F₂ and F₃ generations from R x R, N x N, and S x S crosses among the five differential cultivars, indicating that the resistance genes in the five cultivars are alleles at a common locus. The alleles in PI 96983 and Ogden were previously labeled Rsy and rsyt, respectively. Gene symbols, Rsyy, Rsym, and Rsyk are proposed for the resistance genes in York, Marshall, and Kwanggyo, respectively. It is also proposed that the gene symbol rsyt be changed to Rsyt to more accurately reflect its genetic relationship to the susceptible allele.
The R x S crosses with PI 486355 and Suweon 97 as resistant parents segregated 15R:1S in the F₂ and 7 (all R) : 4 (3R:1S) : 4 (15R:1S) : 1 (all S) in the F₃, indicating that each has two independent genes for resistance to SMV. The F₂ plants of PI 486355 x Suweon 97 showed no segregation for SMV reaction, suggesting that they have at least one gene in common. The crosses among all 7 resistant parents produced no susceptible segregates when inoculated with strain G1. It is concluded that the 7 resistant cultivars each have a gene or allele at the Rsy locus.
Data from the experiments furnished conclusive evidence that the necrotic reaction in segregating populations is highly associated with plants that are heterozygous for the resistance gene.Ph. D.
27
Chang, Peta-Gaye Suzette. "Plant Virus Diagnostics: Comparison of classical and membrane-based techniques for immunoassay and coat protein sequence characterization for Cucumber mosaic virus and three potyviruses". Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/28017.
Resumen
Diagnostics is important in the development and implementation of pest management strategies. The virus diagnostic capabilities of several plant pathology collaborators within the Integrated Pest Management Collaborative Research Support Program (IPM CRSP) host countries were evaluated with the aid of a survey. Very few plant disease diagnostic clinics had funds to cover daily operations despite over half of the responding clinics receiving an operational budget. Academically and government affiliated clinics within the developing host countries had little access to molecular tools and equipment, relying mostly on biological and serological methods. Clinics affiliated with private companies and within the USA relied more upon molecular assays. Ten CMV isolates identified by tissue blot immunoassay (TBIA) were collected from a garden at the Historic Smithfield Plantation on the Virginia Tech campus, and from Painter, Virginia on the Eastern Shore. Three CMV isolates from Smithfield were biologically compared to six early CMV isolates stored since the 1970s, while all isolates were compared serologically and molecularly. Sequences obtained after reverse transcription-polymerase chain reaction (RT-PCR) assigned the CMV isolates into subgroups, with eleven to subgroup 1A and three to subgroup 2. The subgroup assignments were confirmed by TBIA using CMV subgroup-specific monoclonal antibodies (Agdia Inc). At Smithfield Plantation, another virus, Turnip mosaic virus (TuMV) was identified from Dameâ s Rocket (Hesperis matronalis L.). This is the first report of TuMV in Virginia. In TBIA virus-infected plant samples are blotted onto nitrocellulose membranes, dried, and processed. Membranes can be stored for long periods of time and transported safely across borders without risk of introducing viruses into new environments, but virus remains immunologically active for several months. Methods were developed with CMV and three potyviruses, using the same membranes, for detecting viral RNA by RT-PCR and direct sequencing of PCR products.. Amplification by RT-PCR was possible after membrane storage for up to 15 months. The membranes also performed well with samples sent from IPM CRSP host countries and within the USA. This method should improve molecular diagnostic capabilities in developing countries, as samples can be blotted to membranes and sent to a centralized molecular laboratory for analysis.Ph. D.
28
Frangioni, Desiré Spada dos Santos [UNESP]. "Identificação e purificação de isolados de Cucumber mosaic virus e triagem de genótipos de pimentão para resistência". Universidade Estadual Paulista (UNESP), 2001. http://hdl.handle.net/11449/97246.
Resumen
Made available in DSpace on 2014-06-11T19:28:37Z (GMT). No. of bitstreams: 0
Previous issue date: 2001-12Bitstream added on 2014-06-13T19:37:31Z : No. of bitstreams: 1
frangioni_dss_me_botfca.pdf: 542597 bytes, checksum: 287866285220c5f30edfb16af2d32683 (MD5)No período de 1998 à 2001, 17 amostras de pimentão ‘Magali-R’ (Capsicum annuum L.) com sintomas de mosaico sistêmico, nanismo, deformação foliar e dos frutos, causando severos danos e perdas econômicas, foram coletadas nas regiões produtoras de Paulínia, Lins, Jacareí, Guaiçara e Lucianópolis, municípios do Estado de São Paulo. Essas amostras foram caracterizadas através de círculo de hospedeiras, DAS-ELISA com o emprego de anticorpo monoclonal contra o CMV-I e CMV-II. Um isolado de cada região foi caracterizado molecularmente, quanto ao subgrupo através da RT-PCR e RFLP com a endonuclease de restrição MspI. As amostras foram inoculadas em plantas indicadoras que reagiram com sintomas típicos do Cucumber mosaic virus (CMV), entre estas, Nicotiana glutinosa demonstrando mosaico sistêmico e ausência de necrose, indicou que os isolados do CMV, em estudo, pertenciam ao subgrupo I. N. glutinosa foi utilizada para manter os isolados, para os testes de ELISA, extração de RNA total e como multiplicadora do vírus para a purificação. Todos os isolados testados no DAS-ELISA reagiram positivamente ao anticorpo monoclonal específico para o CMV-I e negativamente para o CMV-II. Os isolados 1, 3, 4, 15 e 17 foram amplificados com sucesso através da RT-PCR, e produziram um fragmento de 486 pb, tamanho esperado para o subgrupo I. Fragmento que ao ser digerido pela MspI, resultou em duas bandas de 150 e 336 pb, padrão esperado para o CMV-I. O método utilizado na purificação foi eficiente, resultando em uma preparação do CMV purificado, cujo rendimento foi de 40 mg/kg de tecido infectado, permitindo a imunização de galinhas e a produção de um antissoro policlonal específico à partir das gemas dos ovos. O antissoro apresentou alto título em ELISA indireto. A triagem de genótipos de pimentão para a resistência ao CMV... .
During the years 1998 to 2001, 17 samples of sweet peppers ‘Magali- R’ (Capsicum annuum L.) showing systemic mosaic, stunt, leaf and fruit distortion, causing severe damage and economic losses, were collected from Paulínia, Lins, Jacareí, Guaiçara and Lucianópolis, regions of São Paulo State. These samples were characterized by host range and DAS-ELISA with monoclonal antibodies against CMV I and CMV II. One isolate from each region was also characterized by RT-PCR and RFLP with restriction enzyme MspI. The plants host range revelead the presence of the Cucumber mosaic virus (CMV) in all samples. The symptom reaction in Nicotiana glutinosa was sistemic mosaic without necrosis, indicating that all CMV isolates belongs to subgroup I. The CMV isolates were also propagated and mantained in this host for the ELISA test and total RNA extration. All isolates tested by DAS-ELISA reacted positively with CMV I specific monoclonal antibodies and negatively with CMV II. The isolates 1, 3, 4, 15 e 17 were successfully amplified by the RTPCR and produced a fragment of 486 pb, the expected size for CMV subgroup I. These fragments when digested by MspI produced two bands of 150 and 336 pb, restriction pattern expected for the CMV subgroup I. Purified CMV yielding was 40mg/kg of infected leaves. The method used was efficient to produce a good purified preparation utilized to immunize chickens that produced specific antiserum with high titer. Screening of sweet peppers resistance to CMV showed immunity of AF-97A and tolerance of AF-188, AF-1178, AF-98 A, AF-99 A and AF-136 A. The hybrid progenies Lamuyo, Reinger, Mayata, Mônica, Magali, Mikalor, Esterel, Melody and “All Big” cultivar showed immune plants. These results are promising to sweet pepper breeding for resistance to CMV.
29
Frangioni, Desiré Spada dos Santos 1968. "Identificação e purificação de isolados de Cucumber mosaic virus e triagem de genótipos de pimentão para resistência /". Botucatu : [s.n.], 2001. http://hdl.handle.net/11449/97246.
Resumen
Resumo: No período de 1998 à 2001, 17 amostras de pimentão 'Magali-R' (Capsicum annuum L.) com sintomas de mosaico sistêmico, nanismo, deformação foliar e dos frutos, causando severos danos e perdas econômicas, foram coletadas nas regiões produtoras de Paulínia, Lins, Jacareí, Guaiçara e Lucianópolis, municípios do Estado de São Paulo. Essas amostras foram caracterizadas através de círculo de hospedeiras, DAS-ELISA com o emprego de anticorpo monoclonal contra o CMV-I e CMV-II. Um isolado de cada região foi caracterizado molecularmente, quanto ao subgrupo através da RT-PCR e RFLP com a endonuclease de restrição MspI. As amostras foram inoculadas em plantas indicadoras que reagiram com sintomas típicos do Cucumber mosaic virus (CMV), entre estas, Nicotiana glutinosa demonstrando mosaico sistêmico e ausência de necrose, indicou que os isolados do CMV, em estudo, pertenciam ao subgrupo I. N. glutinosa foi utilizada para manter os isolados, para os testes de ELISA, extração de RNA total e como multiplicadora do vírus para a purificação. Todos os isolados testados no DAS-ELISA reagiram positivamente ao anticorpo monoclonal específico para o CMV-I e negativamente para o CMV-II. Os isolados 1, 3, 4, 15 e 17 foram amplificados com sucesso através da RT-PCR, e produziram um fragmento de 486 pb, tamanho esperado para o subgrupo I. Fragmento que ao ser digerido pela MspI, resultou em duas bandas de 150 e 336 pb, padrão esperado para o CMV-I. O método utilizado na purificação foi eficiente, resultando em uma preparação do CMV purificado, cujo rendimento foi de 40 mg/kg de tecido infectado, permitindo a imunização de galinhas e a produção de um antissoro policlonal específico à partir das gemas dos ovos. O antissoro apresentou alto título em ELISA indireto. A triagem de genótipos de pimentão para a resistência ao CMV... (Resumo completo, clicar acesso eletrônico abaixo).Abstract: During the years 1998 to 2001, 17 samples of sweet peppers 'Magali- R' (Capsicum annuum L.) showing systemic mosaic, stunt, leaf and fruit distortion, causing severe damage and economic losses, were collected from Paulínia, Lins, Jacareí, Guaiçara and Lucianópolis, regions of São Paulo State. These samples were characterized by host range and DAS-ELISA with monoclonal antibodies against CMV I and CMV II. One isolate from each region was also characterized by RT-PCR and RFLP with restriction enzyme MspI. The plants host range revelead the presence of the Cucumber mosaic virus (CMV) in all samples. The symptom reaction in Nicotiana glutinosa was sistemic mosaic without necrosis, indicating that all CMV isolates belongs to subgroup I. The CMV isolates were also propagated and mantained in this host for the ELISA test and total RNA extration. All isolates tested by DAS-ELISA reacted positively with CMV I specific monoclonal antibodies and negatively with CMV II. The isolates 1, 3, 4, 15 e 17 were successfully amplified by the RTPCR and produced a fragment of 486 pb, the expected size for CMV subgroup I. These fragments when digested by MspI produced two bands of 150 and 336 pb, restriction pattern expected for the CMV subgroup I. Purified CMV yielding was 40mg/kg of infected leaves. The method used was efficient to produce a good purified preparation utilized to immunize chickens that produced specific antiserum with high titer. Screening of sweet peppers resistance to CMV showed immunity of AF-97A and tolerance of AF-188, AF-1178, AF-98 A, AF-99 A and AF-136 A. The hybrid progenies Lamuyo, Reinger, Mayata, Mônica, Magali, Mikalor, Esterel, Melody and "All Big" cultivar showed immune plants. These results are promising to sweet pepper breeding for resistance to CMV.
Orientador: Marcelo Agenor Pavan
Coorientador: Addolarata Colariccio
Mestre
30
Lewsey, Mathew Graham. "Effects of the Cucumber mosaic virus 2b gene and other viral sequences in transgenic plants". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614169.
31
Qusus, Saba J. "Molecular Studies on Soybean Mosaic Virus-Soybean Interations". Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30328.
Resumen
In the U.S., soybean mosaic virus (SMV) is classified into seven strain groups, designated G1 to G7, based on their different responses on resistant soybean [Glycine max (L.) Merr.] cultivars. These responses are: symptomless or resistant (R), necrotic (N), and mosaic or susceptible (S). The gene-for-gene model has been proposed for SMV-soybean interactions. In the majority of cultivars, a single dominant gene, Rsv1, confers both the R and N responses. In the first part of this study, the coat protein (CP) genes of two SMV strains, G1 and G6 were isolated, cloned, and sequenced. Gene isolation was done by reverse transcription-polymerase chain reaction (RT-PCR) on partially purified virus preparation without prior RNA extraction. Amplified products were blunt-end ligated into pNoTA/T7 vector and transformed into competent cells. Sequencing was performed in both directions on heat-denatured double-stranded plasmids. The predicted 265 amino acid sequence of the CP of G1 and G6 strains were 98.9% identical, with only two amino acid differences. Correlating the CP sequences of G1, G2, G6, and G7, with their virulence on resistant soybean cultivars indicated that the CP is not likely to be the R- and/or N-determinant in the SMV-soybean system. The second part of the study involved studying the pathogenesis of G1, G6, and G7 strains on inoculated leaves of R, N, and S soybean cultivars by leaf imprint immunoassay. Results indicated four types of reactions: i) susceptible, showing unrestricted replication and spread; ii) immune, where no virus was detected; iii) systemic spread, showing unrestricted replication but limited spread along the veins; and iv) restricted replication and spread, where infection was restricted to few foci along the veins. Results of this study indicated that Rsv1-mediated resistance is a multicomponent type of resistance that involves both inhibition of virus replication as well as cell-to-cell movement. The third part of the study aimed at investigating Rsv1-mediated resistance at the cellular level. For this purpose, an SMV-soybean protoplast system was developed. Protoplast isolation was based on a combined cellulase-pectolyase Y-23 digestion and metrizamide-sorbitol gradient purification protocol. Virus inoculation of protoplasts was facilitated by either polyethelene glycol (PEG) or poly-L-ornithine (PLO), and method of detection was by Western blotting using antiserum to whole virus. Inoculation by PEG was successful, but results were irreproducible because of the adverse effect of PEG on protoplast viability. Inoculation by PLO was inconclusive because of the high background from residual inoculum. Additional research is needed before a protoplast system can be used to study the mechanism of Rsv1 resistance to SMV at the cellular level.Ph. D.
32
Holness, Claire Louise Lesley. "Isolation and characterisation of mutants of cowpea mosaic virus". Thesis, University of Warwick, 1989. http://wrap.warwick.ac.uk/59381/.
Resumen
A nitrous acid-induced, temperature sensitive mutant of cowpea mosaic virus (CPMV) known as 8-14, (Evans 1985, Virology 1985, 141, 275-282), was characterised. The phenotypic defect in 8 -14 was shown not to affect translation of the RNA or the first proteolytic cleavage of the B RNA-encoded polyprotein. The defect is probably at the level of genome replication. The technique of two dimensional RNA fingerprinting showed the mutant genome to be similar to the parental wild-type but did not resolve the genetic alteration(s) specific for the mutation. The mechanism of CPMV translation was investigated by site-directed mutagenesis of a full-length cDNA clone of CPMV M RNA from which infectious RNA could be generated by in vitro transcription. The results obtained confirm the AUG at position 161 is used to direct the synthesis of the 105K protein in vitro. The detection of a 58K protein in infected protoplasts suggests that it is also used in vivo. The synthesis of the 95K protein can be initiated from either of the AUGs at positions 512 and 524. Synthesis of this protein is not essential for CPMV replication in protoplasts. Several deletion mutations were created in the M RNA cDNA clone in order to determine the regions of M RNA essential for replication of M RNA. Analysis of one mutant indicated that sequences between 1446 and 1620 are probably not required for replicase recognition. However, the accumulation of this mutant in protoplasts was reduced, presumably as a result of lack of encapsidation of the RNA as this mutant is thought not to synthesise functional coat protein. Data from several mutants showed that alterations of M RNA around nucleotides 161 and 189 prevent transcript accumulation in protoplasts possibly owing to a severe reduction in replicability of the input RNA.
33
Mendonca, A. P. A. "Some aspects of the host involvement in cowpea mosaic virus replication". Thesis, University of East Anglia, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370391.
34
Atkins, David G. "Studies on the cell-to-cell movement of tobacco mosaic virus". Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276159.
35
Surette, Monique Angela. "Host- and tissue-specific roles of the 2b protein of Cucumber mosaic virus in Arabidopsis thaliana". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608730.
36
Robertson, Fiona Catherine. "Selective targeting of micro RNA-regulated plant development by the 2b protein of Cucumber mosaic virus". Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613182.
37
Fisher, John R. "Partial characterization of a Cucumber Mosaic Virus Isolate, and its associated Satellite RNA, from Ajuga Reptans /". The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488191124570172.
38
Torres, Arzayus Maria Isabel. "Engineering yam mosaic virus resistance in Nicotiana benthamiana using genetic transformation techniques". Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264199.
39
Cooper, Laura B. "The potential effects of red imported fire ants (Solenopsis invicta) on arthropod abundance and Cucumber mosaic virus". Auburn, Ala., 2005. http://repo.lib.auburn.edu/Send%2012-16-07/COOPER_LAURA_14.pdf.
40
Ligat, Julio S. "Pathology and distribution in the host of pea seed-borne mosaic virus". Title page, contents and summary only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phl723.pdf.
Resumen
Includes bibliographical references (leaves 82-92). Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species
41
Hajimorad, Mohammad Reza. "Variation in alfalfa mosaic virus with special reference to its immunochemical properties". Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phh154.pdf.
Resumen
Includes Appendix listing other publications by the author. Includes bibliographical references (leaves 134-181). Alfalfa mosaic virus was isolated from lucerne (Medicago sativa) plants with a variety of disease symptoms. Experiments showed that each isolate was biologically distinct and that the host range and symptomatology of each isolate was affected by the environmental condition.
42
Kalogirou, Maria. "Antiviral and quality effects of chemical elictors and Cucumber Mosaic Virus (CMV) infection on tomato plants and fruits". Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7278.
Resumen
Cucumber mosaic virus (CMV) has emerged as one of the most serious threats to tomato cultivation in Greece. In the present study the effects of Benzothiadiazoles (BTH) and pyraclostrobin against mechanically or aphid-transmitted CMV in tomato plants, of hybrid F1 Clodin, were investigated in greenhouse experiments. BTH was confirmed as capable of inducing systemic acquired resistance (SAR) in tomato seedlings against CMV, while pyraclostrobin was not. Responses to BTH application and/or CMV inoculation on Spanish tomato hybrid Delos (BTH, BTH+CMV, CMV treatments) were monitored during winter and spring season in Greece. In both seasons the SAR derived from BTH application suppressed CMV. BTH treatment presented increased plant growth, fruit size and marketable tomato yield compared to CMV and BTH+CMV treatments, whereas decreased compared to healthy control. CMV treatment caused the most severe stunting of tomato plants among the examined treatments and resulted in yield loss of marketable fruits, although the total fruit number was higher versus to other treatments. Cont/d.
43
Beekwilder, Kristen M. "The Inheritance of Resistance to Tobacco Mosaic Virus in Tobacco Introductions". Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/31726.
Resumen
Thirty-one tobacco introductions that were reported to display either a local lesion or a symptomless reaction to infection with tobacco mosaic virus (TMV) were screened for reaction to the virus (Chaplin and Gooding, 1969). Ten tobacco introductions (TI), TI 203, TI 407, TI 438, TI 450, TI 692, TI 1203, TI 1459, TI 1462, TI 1467, and TI 1500 were randomly chosen for further study to characterize their resistance to tobacco mosaic virus (TMV). Each TI line was crossed with susceptible cultivar K 326 to determine the mode of inheritance of resistance to TMV. The F2 progeny of TIs 1459, 1462, and 1500 segregated in a 3 local lesion:1 mosaic ratio, indicating that the gene governing resistance in these three TI lines was a single, dominant trait. The F2 progeny of TIs 203, 407, 438, 450, 692, 1203, and 1467 failed to segregate, only mosaic plants were observed. This would indicate that the gene(s) controlling resistance to TMV in these lines would not provide resistance for plant breeders to incorporate into a breeding program. Each TI line was also crossed with local lesion cultivar NC 567, which contains the N gene, in order to determine if the gene(s) governing resistance in the TI lines was allelic to the N gene in NC 567. The F2 progeny of TIs 1459 and 1462 did not segregate. All progeny displayed the local lesion reaction to TMV indicating that the gene governing resistance in these two lines is allelic to the N gene. The F2 progeny of the cross between TI 1500 and NC 567 segregated in a 15 local lesion: 1 mosaic ratio, which indicates that the gene controlling resistance in TI 1500 is not allelic to the N gene. When crossed with NC 567, the F2 progeny of TIs 407, 438 and 1467, segregated in a 3 local lesion: 1 mosaic ratio. No symptomless plants were observed. There was also segregation in the F2 progeny of the crosses between NC 567 and TIs 203, 450, 692, and 1203. However, the segregation was in no discernible ratio. Once again the F2 progeny of the crosses either displayed a local lesion or mosaic reaction and no symptomless progeny were observed. This would again indicate that the symptomless TI lines do no provide heritable resistance to TMV and therefore are not acceptable as an alternative source of resistance to TMV for the plant breeder. Tobacco introduction 1500 should be investigated further because a single, dominant trait that is not allelic to the N gene governs resistance to TMV in this line.Master of Science
44
Jinqiang, Yan. "Study of the resistance to Cucumber mosaic virus aggressive strains in the melon (Cucumis melon L.) accession PI 161375". Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666767.
Resumen
L’accessió exòtica de meló PI 161375 cultivar Songwhan Charmi (SC) presenta resistència a la major part de soques de Cucumber mosaic virus (CMV). S’ha descrit que la resistència a soques del subgrup II de CMV és recessiva i que està controlada pel gen cmv1, que és capaç d’evitar l’entrada del virus al floema mitjançant una restricció a nivell de les cèl·lules de la beina. Aquesta restricció depèn de la proteïna de moviment (MP) viral, que és el determinant de la virulència. Per tenir resistència a la soca CMV-M6, pertanyent al subgrup I, a part de cmv1, també es requereixen dos altres QTLs: cmvqw3.1 i cmvqw10.1. No obstant, una soca més agressiva del subgrup I, CMV-FNY, és capaç de superar la resistència conferida per cmv1/cmvqw3.1/cmvqw10.1. Aquesta tesis té com objectius (i) identificar altres QTLs responsables de la resistència a CMV-FNY, (ii) caracteritzar la resistència conferida pels QTLs cmv1/cmvqw3.1/cmvqw10.1, i (iii) identificar els factors de virulència implicats en aquests tres QTLs. L’anàlisi de QTLs es va dur a terme mitjançant diverses poblacions F2 obtingudes del creuament entre les línies resistents a CMV-FNY, DHL142 i DHL69, i línies susceptibles. Es van detectar alguns possibles QTLs d’efecte menor als LG II, LG IX, LG X i LG XII. No obstant, cap d’aquests QTLs va ser reproduïble a les diferents poblacions avaluades, ni pels diferents mètodes de fenotipat utilitzats. Un cop avaluat el sistema d’anàlisi de QTLs emprat es va demostrar que aquest no havia estat l’apropiat per QTLs d’efecte menor. Probablement el factor limitant hauria estat la robustesa de l’avaluació fenotípica de la infecció en poblacions F2. L’estudi de la resistència, conferida per combinacions de dos o tres QTLs, va mostrar que malgrat les plantes s’acabaven infectant per CMV-FNY, hi havia un retard en la infecció, indicant que la resistència intervé restringint el moviment viral. Més endavant es va demostrar que la restricció actua a nivell de l’entrada al floema, enlloc d’intervenir a nivell del moviment del virus un cop dins del floema. Així doncs, cmvqw3.1 i cmvqw10.1 actuen dificultant el moviment de CMV-FNY al mateix punt de la infecció viral on ho fa cmv1 amb CMV-LS.
La generació de pseudorecombinants entre CMV-FNY / CMV-M6 i CMV-FNY / CMV-LS va demostrar que el determinant de la virulència no es troba al RNA3.
Aquests resultats suggereixen que la resistència a CMV de l’accessió SC es construeix mitjançant diferents nivells, essent cmv1 el primer nivell conferint resistència envers el subgrup II; el segon nivell cmvqw3.1 i cmvqw10.1 conferint una resistència eficient envers CMV-M6; i un tercer nivell on altres QTLs encara per determinar serien necessaris
per conferir una resistència eficient a CMV-FNY. Actualment, sabem que els dos primers nivells de resistència estarien actuant restringint l’entrada de CMV al floemaLa accesión de melón exótico PI 161375, cultivar Songwhan Charmi (SC) es resistente a la mayoría de las cepas de Cucumber mosaic virus (CMV). La resistencia a las cepas del subgrupo II de CMV es recesiva y controlada por el gen cmv1, que es capaz de prevenir la entrada del virus en el floema deteniéndolo en las células de la vaina que rodean la vena. Esta restricción depende de la proteína de movimiento (MP), el determinante de la virulencia frente a este gen. Para resistir a la cepa CMV-M6, del subgrupo I, se requieren dos QTL más, cmvqw3.1 y cmvqw10.1, funcionando en colaboración con cmv1. Sin embargo, CMV-FNY, una cepa más agresiva del subgrupo I, es capaz de superar la resistencia conferida por cmv1/cmvqw3.1/cmvqw10.1. En esta tesis, nuestro objetivo es (i) identificar los QTL adicionales responsables de la resistencia a CMV-FNY, (ii) caracterizar la resistencia conferida por los QTL cmv1/cmvqw3.1/cmvqw10.1 e (iii) identificar los factores de virulencia involucrados con estos QTL. El análisis de QTL se abordó desarrollando varias poblaciones F2 entre las líneas DHL142 o DHL69, resistentes a CMV-FNY, y varias líneas de melón susceptibles a CMV-FNY, donde se detectaron varios QTL menores en LG II, LG IX, LG X y LG XII. Sin embargo, ninguno de estos QTLs fue detectado reproduciblemente en varias poblaciones F2, ni utilizando diferentes métodos de fenotipado, lo que indicó que nuestro sistema de detección de QTL no es apropiado para detectar QTLs menores. El factor limitante más probable puede ser la dificultad del fenotipado de la infección para la detección de QTLs en una población F2. El estudio de la resistencia conferida por combinaciones de dos o los tres QTL mostró que, aunque las plantas eran susceptibles a CMV-FNY, hubo un retraso en la infección, lo que indica que la resistencia implica una restricción del movimiento viral. Un análisis posterior mostró que la restricción funcionaba al nivel de la entrada al floema, más que al nivel del movimiento dentro del floema. Por lo tanto, esto indica que cmvqw3.1 y cmvqw10.1 están dificultando el movimiento de CMV-FNY en el mismo paso de la infección viral donde cmv1 restringe CMV-LS. Los pseudorecombinantes generados entre CMV-FNY / CMV-M6 y entre CMV-FNY / CMV-LS demostraron que el determinante de virulencia no mapeaba en el RNA3. Tomados en conjunto, nuestros resultados sugieren que la resistencia al CMV en la accesión SC está formada por una serie de niveles de resistencia, siendo cmv1 el primer nivel, efectivo contra las cepas del subgrupo II; el segundo nivel, formado por cmvqw3.1 y cmvqw10.1, que cooperarían con cmv1 para proporcionar resistencia frente a CMV-M6; y el tercer nivel sería el QTL no identificado aún, necesario para la resistencia frente a CMV-FNY. En la actualidad, sabemos que los dos primeros niveles de resistencia estarían participando en la restricción de la entrada de CMV al floema.
The exotic melon accession PI 161375 cultivar Songwhan Charmi (SC) shows resistance to most of Cucumber mosaic virus (CMV) strains. The resistance to CMV subgroup II strains was reported as recessive, controlled by the gene cmv1 which is able to prevent the phloem entry of the virus by restricting it in the bundle sheath cells. This restriction depends on the movement protein (MP), the determinant of virulence. Two more QTLs, cmvqw3.1 and cmvqw10.1 are required, working together with cmv1, for the resistance to the subgroup I strain CMV-M6. However, CMV-FNY, a more aggressive strain from subgroup I, was able to overcome the resistance conferred by cmv1/cmvqw3.1/cmvqw10.1. In this thesis we aim to (i) identify the additional QTLs responsible for the resistance to CMV-FNY, (ii) characterize the resistance conferred by the QTLs cmv1/cmvqw3.1/cmvqw10.1 and (iii) identify the virulence factors involved with these QTLs. QTL analysis was addressed developing several F2 populations made between the CMV-FNY-resistant lines DHL142, DHL69 and several CMV-FNY-susceptible melon lines. Several putative minor QTLs were detected in LG II, LG IX, LG X and LG XII. However, none of these QTLs were reproducibly detected neither in several F2 populations nor using different methods of phenotyping. The evaluation of our QTL detecting system indicated that it is not appropriate for detecting minor QTL, being the most probable limiting factor the correct phenotyping of the infection for QTL detection in a F2 population. The study of the resistance conferred by combinations of two or the three QTLs showed that, although the plants were susceptible to CMV-FNY, there was a delay in the infection, indicating that the resistance involves a restriction of the viral movement. Further analysis showed that the restriction worked at the level of phloem entry, rather than at the level of movement within the phloem. Therefore, this indicates that cmvqw3.1 and cmvqw10.1 are impairing CMV-FNY movement at the same step of the viral infection where cmv1 restricts CMV-LS. Pseudorecombinants generated between CMV-FNY / CMV-M6 and between CMV-FNY / CMV-LS demonstrated that the determinant of virulence was not mapped in RNA3. Taken together, our results suggest that the resistance to CMV in SC accession is built by a series of resistance layers, being cmv1 the first layer, against subgroup II strains; the second layer, cmvqw3.1 and cmvqw10.1, that provide efficient resistance to CMV-M6; and the third layer being the unknown QTL, necessary for efficient resistance to CMV-FNY. At present, we know that the first two layers of resistance would be working in the restriction of CMV entry to the phloem.
45
Bertioli, David John. "The coat protein of arabis mosaic virus and it's expression in plants, insect cells and bacteria". Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306084.
46
Li, Dora. "The Ncm-1 gene for resistance to Cucumber mosaic virus in yellow lupin (Lupinus luteus): molecular studies and marker development". Thesis, Li, Dora (2012) The Ncm-1 gene for resistance to Cucumber mosaic virus in yellow lupin (Lupinus luteus): molecular studies and marker development. PhD thesis, Murdoch University, 2012. https://researchrepository.murdoch.edu.au/id/eprint/10623/.
Resumen
Cucumber mosaic virus (CMV) is an important virus pathogen of lupins in Australia which causes serious yield losses of up to 60% in epidemic years. In commercially grown lupin (Lupinus angustifolius and L. luteus) crops CMV is spread non-persistently by aphid vectors, but it can also be seed borne and this extends virus infection into successive generations. Resistance to CMV has been identified in L. luteus cv. Wodjil and is the conferred by the Ncm-1 gene. The aims of this research were to study the Ncm-1 gene in order to gain a better understanding of resistance in yellow lupin, and to develop a molecular marker linked to Ncm-1 for use in marker assisted selection.
Previously published data by Jones et al (1996) identified Ncm-1 as being a single dominant resistance gene, however, phenotypic analysis of CMV infection in a segregating L. luteus mapping population in this thesis was consistent with the Ncm-1 gene being a dominant gene modified by at least one other minor gene. The polygenic nature of CMV resistance in this genetic background was further supported by AFLP analysis which identified one major and one minor QTL associated with resistance.
A PCR based approach, using degenerate primers designed on conserved disease resistance protein motifs, was used to identify resistance gene analogues (RGA) in L. luteus. Comparative analysis revealed that RGAs isolated from L. luteus were members of the TIR-NBS-LRR class of R proteins and were similar to the TMV resistance gene N identified in tobacco and the RT4-4 CMV resistance gene from pepper. Extensive comparative analysis using the genomes of model species (including Medicago truncatula, Glycine max, Arabidopsis thaliana and Lotus japonicus) was explored and validated the assignment from L. luteus RGAs to the category of candidate gene for CMV resistance. The RGAs identified in L. luteus were found to be highly conserved in both the CMV resistant and susceptible varieties tested. SNPs which resulted in non-synonymous mutations were identified using cDNA based 5’ RACE and used to develop a single nucleotide primer extension (SNuPE) assays for MALDI-ToF mass spectrophotometric analysis. As SNuPE is based on the allele specific extension of a single nucleotide, genotyping is highly accurate and provides co-dominant information. Two SNuPE assays were developed based on the RGAs isolated and validated on bulked samples from two L.luteus populations segregating for CMV resistance. One assay, SNuPE A267→C was found to associate with CMV resistance. This co-dominant assay is the first of its kind reported for yellow lupin.
47
Thivierge, Karine. "Protein-protein interactions in turnip mosaic potyvirus replication complex". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80886.
Resumen
Interactions between plant and virus proteins play pivotal roles in many processes during the viral infection cycle. Analysis of protein-protein interactions is crucial for understanding virus and host protein functions and the molecular mechanisms underlying viral infection. Several interactions between virus-encoded proteins have been reported. However, few interactions between viral and plant proteins have been identified so far. To examine interactions between Turnip mosaic potyvirus (TuMV) proteins and plant proteins, recombinant proteins were produced and used in ELISA-type assays and in in vitro co-immunoprecipitation experiments. An interaction between TuMV P1 proteinase and wheat poly(A)-binding protein (PABP) was identified. An interaction between P1 protein and the plant Arabidopsis thaliana eukaryotic initiation factor (iso)4E [eIF(iso)4E] was also found. Finally, potential interactions between both TuMV CI and P1 proteins and between TuMV CI protein and eIF(iso)4E were identified.
48
Torok, Valeria Anna. "Biological and molecular variation among isolates of pea seed borne mosaic virus". Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09pht686.pdf.
Resumen
Corrigendum inserted at the back. Includes bibliographical references (leaves 133-158). Ch. 1. General introduction -- ch. 2. General materials and methods -- ch. 3. Biological characterisation of Australian PSbMV isolates -- ch. 4. Developing nucleic acid based diagnostics for PSbMV -- ch. 5. Detection of PSbMV isolates by RT-PCR and RFLP analysis -- ch. 6. Developing an internal control for PSbMV RT-PCR -- ch. 7. Molecular analysis of the PSbMV VPG -- ch. 8. PSbMV sequence and phylogenetic analysis -- ch. 9. General discussion Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays.
49
Fonseca, Guilherme Cordenonsi da. "Identificação da integração do vírus do mosaico do pepino no genoma da soja e seu reconhecimento pelo sistema de produção de pequenos RNAs". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/37427.
Resumen
A soja (Glycine max) é uma das culturas mais importantes do mundo, os seus grãos servem tanto para a alimentação quanto para a extração de óleo para a fabricação do biodiesel. O vírus do mosaico do pepino (CMV, do inglês, “Cucumber mosaic virus”) é um vírus de RNA, patogênico a diversas plantas. O RNA de interferência é um sistema de silenciamento de RNA presente na maioria dos eucariotos no qual precursores de RNA de dupla fita (dsRNA) são processados em pequenos RNAs (sRNAs) de 21-24 nucleotídeos (nt), que podem regular a atividade de genes, elementos genéticos e vírus de uma maneira sequência específica. A integração de vírus de DNA e de retrovírus no genoma do hospedeiro já é bem conhecida tanto para sistemas eucarióticos quanto para procarióticos. Mais recentemente, foi observada a integração de vírus de RNA não retrovirais (NIRVs) em mamíferos. O presente trabalho é o primeiro a demonstrar tal evento no genoma de plantas. A partir das sequências dos sRNAs de 19-24 nt de 15 bibliotecas de sRNAs sequenciados de amostras de tecidos de soja, foram montadas sequências contíguas (“contigs”) pelo programa SOAP, algumas das quais apresentaram homologia de sequência ao RNA 1 do CMV. Por montagem de novo desses contigs foi obtida uma sequência de 3.092 nt do RNA 1 do CMV, presente em todas as bibliotecas pesquisadas de pelo menos cinco cultivares diferentes de soja. A presença dessa sequência foi confirmada em outras sete cultivares, exceto em "Willians". Foi observada uma maior presença de sRNAs derivados do CMV senso do que anti-senso nas 15 bibliotecas sequenciadas. Os sRNAs de 22-nt foram os mais abundantes. Para o vírus da mancha da vagem do feijoeiro (BPMV, do inglês “Bean pod mottle virus”) presente em uma das bibliotecas, os sRNAs de 21-nt e 22-nt representaram em torno de 80% do total de sRNAs. Foram encontrados sRNAs que variaram sob estresse biótico (Phakospora pachyrhizi) e abiótico (seca) e entre diferentes cultivares. A expressão do RNA 1 aumentou nas plantas sob estresse. Provavelmente o evento de integração ocorreu via recombinação à um retrotransposon.The Soybean (Glycine max) is one of the world's most important crops, its seeds are used both as food and for the extraction of oil to manufacture biodiesel. The Cucumber mosaic virus (CMV) is a pathogenic RNA virus of plants. The RNA interference is a system of RNA silencing present in most eukaryotes in which precursors of double-stranded RNA (dsRNA) are processed into small RNAs (sRNAs) of 21-24 nucleotides (nt), which can regulate the activity of genes, genetic elements and virus in a sequence-specific manner. The integration of DNA virus and retrovirus into the host genome is well known both for prokaryotic and eukaryotic systems. The integration of non-retroviral RNA virus (NIRVs) in mammals was previously observed, but the present work is the first to demonstrate such an event in a plant genome. The sequences of the sRNAs ranging from 19 to 24 nt, in 15 libraries of sRNAs sequenced from samples of soybean tissues, were assembled in contigs by the program SOAP, with some preentering sequence homology to the RNA 1 of CMV. By de novo assembling of these contigs it was obtained a sequence of 3,092 nt of the CMV RNA 1, present in all libraries surveyed in at least five different varieties of soybeans. The presence of this sequence was confirmed by PCR in seven other cultivars, but in "Williams". We observed a greater presence of sRNAs derived from CMV of sense orientation than antisense in the 15 libraries sequenced. The 22-nt sRNAs were the most abundant. For the Bean pod mottle virus (BPMV), present in one of the libraries, the 21 and 22 nt sRNAs were represented by around 80% of all sRNAs. The sRNAs were found varying under biotic stress (Phakospora pachyrhizi) and abiotic (drought) and among different cultivars. RNA 1 expression increased in plants under stress. Probably the integration event occurred via recombination of a retrotransposon.
50
Jiang, Sanjie. "CMV infection affects bumblebee pollination behaviour and plant reproductive success". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275637.
Resumen
Viruses can affect plant-insect interactions by altering emission of plant volatile organic compounds (VOCs). Previous work in the lab suggested that VOCs emitted by tomato (Solanum lycopersicum) plants infected with cucumber mosaic virus (CMV) were more attractive to bumblebees (Bombus terrestris) in free choice assays. I extended this work using Arabidopsis thaliana mutants with lesions in genes encoding factors in RNA silencing. In conditioning assays, I confirmed that plant VOC emission is controlled in part by the microRNA regulatory pathway. I used gas chromatography coupled to mass spectrometry and principal component analysis to confirm that CMV infection caused changes in VOC emission by tomato. VOCs collected from non-flowering mock-inoculated and CMV-infected plants were qualitatively distinct from each other. CMV-infected plants also released greater quantities of VOCs than mock-inoculated plants. CMV appears to be both ‘turning up the volume’ of plant volatile emission, whilst ‘tuning’ volatile blend composition so as to diminish levels of a repellant signal. These data are likely to explain how bumblebees can discriminate between VOCs emitted by mock-inoculated and CMV-infected plants. To determine if CMV infection of tomato plants affects plant reproductive success, I carried out a series of bumblebee pollination experiments. Bumblebees pollinate tomato by ‘buzzing’ (sonicating) the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. First, I established that CMV-infected tomato plants produced fruits with a lower seed yield than mock-inoculated plants. When single bumblebees were allowed to buzz-pollinate flowers in a small flying arena, the fruit that developed from buzz-pollinated flowers on virus infected plants had significantly more seeds than fruit from non-visited flowers. Subsequent experiments were performed in a large flying arena. Bumblebees consistently spent longer foraging on the mock-inoculated tomato plants but seed yield was increased by bumblebee pollination in both mock-inoculated as well as virus-infected tomato plants. However, although buzz-pollination significantly enhanced seed yield from CMV-infected plants compared to fruit from non-buzz-pollinated flowers, the yield was higher in buzz-pollinated fruits from mock-inoculated plants. Similar experiments were carried out utilizing a transgenic line of tomato that constitutively expresses the green fluorescent protein in order to estimate the level of cross-pollination from either CMV-infected plants to mock-inoculated plants or vice versa. More pollen from virus-infected plants was transferred to mock-inoculated plants than the reciprocal cross. However, some caution is needed in the interpretation of the larger scale experiments because the tomato plants were affected by a fungal infection. I investigated if the defensive plant hormone salicylic acid (SA) affects bee-perceivable VOC emission. Exogenous SA treatment renders non-flowering tomato plants more attractive to bumblebees in free choice experiments in which bees could only perceive VOCs, but bumblebees spent less time visiting SA-treated flowering tomato plants in the glasshouse (when the bumblebees were allowed unimpeded access to the flowers). Taken together, these data provide evidence that virus infection can affect host-pollinator interactions. Speculatively, CMV infection may change the fitness of susceptible plants via changes in production of pollinator-attractive VOCs and this may affect the balance of resistant or susceptible plants within the host population.