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Search Results: 1 - 10 of 62 matches for " geminivirus "
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Diversidade genética de begomovírus em cultivos de tomateiro no Centro-Oeste Paulista
Cotrim, Marco Antonio de Andrade;Krause-Sakate, Renate;Narita, Nobuioshi;Zerbini, Francisco Murilo;Pavan, Marcelo Agenor;
Summa Phytopathologica , 2007, DOI: 10.1590/S0100-54052007000300017
Abstract: the genetic variability of viruses belonging to the begomovirus genus infecting tomatoes (lycopersicon esculentum mill) on field areas from the mid-western region of s?o paulo state was evaluated. from january 2003 to february 2004, one hundred and sixty-six tomato samples were collected and the presence of begomoviruses detected on 60% of the samples by pcr, using universal primers for the genus. direct sequencing of pcr products of 16 selected samples indicated the possible presence of tomato severe rugose virus (tosrv), sida mottle virus (simov-[br]) and the tentative species tomato yellow vein streak virus (toyvsv-[br]). a possible new species of begomovirus was detected in two samples. the presence of tosrv and simov had not yet been reported in s?o paulo state. these results indicate the existence of genetic diversity of begomovirus species infecting tomatoes in this area, and serve as an alert for breeders searching for resistance against this important group of pathogens.
Fontes de resistência em tomateiro aos begomovírus bissegmentados Tomato yellow spot virus e Tomato severe rugose virus
Hurtado, Francisco D;Gil, Marta A;Zubiaur, Yamila M;Aguilera, Jorge G;Xavier, César Augusto D;Zerbini Junior, Francisco Murilo;Silva, Derly Jose H da;
Horticultura Brasileira , 2012, DOI: 10.1590/S0102-05362012000400013
Abstract: begomoviruses cause diseases of major economic importance in many crops, especially in tropical and subtropical regions. together with other families of viruses, the begomoviruses cause great damage for producers of fresh and processed tomatoes. the objective of this study was to evaluate the behavior of 11 resistant genotypes to tomato yellow leaf curl virus (tylcv) when infected by the begomoviruses tomato severe rugose virus (tosrv) and tomato yellow spot virus (toysv) under greenhouse conditions. tomato plants were inoculated by biobalistic method when displaying two true leaves. viral infection was confirmed by visual observation of symptoms and by dot blot hybridization. genotypes sty2, sty5, sty6 and l7 were selected as promising due to the absence of symptoms and very low viral concentration for both viruses. the resistance genes ty-1 and ty-2 were not effective against the viral species used in the study. the lines ty52, h24 and cln2116b, carrying these genes, exhibited a susceptible behavior.
Caracteriza??o de genótipos de tomateiro resistentes a begomovírus por marcador molecular co-dominante ligado ao gene Ty-1
Nizio, Daniela Aparecida de Castro;Maluf, Wilson Roberto;Figueira, Ant?nia dos Reis;Nogueira, Douglas Willian;Silva, Vanisse de Fátima;Gon?alves Neto, álvaro Carlos;
Pesquisa Agropecuária Brasileira , 2008, DOI: 10.1590/S0100-204X2008001200009
Abstract: the objectives of this study were to evaluate tomato genotypes for begomovirus resistance and to assess ssr-47 fingerprinting patterns associated with alleles ty-1, in hybrids of fresh-market tomato with commercial potential. twenty-four experimental genotypes, heterozygous at ty-1 locus, were infected with begomovirus via grafting, and showed intermediate symptoms compared to the ones identified by homozygous ty-1/ty-1 lines and by susceptible genotypes ty-1+/ty-1+, which indicates the incomplete dominance of the ty-1 allele. these hybrids were considered to possess partial resistance to begomovirus. the experimental hybrids tex-246, tex-261, tex-253, tex-256, tex-262, tex-252, tex-251 and tex-268 combined high total yields with high mean fruit mass. the hybrids tex-246, tex-253, tex-256, tex-262 and tex-252 showed also longer half-life for fruit firmness and were thus considered competitive with current commercial hybrids used as checks. the molecular marker ssr-47 was effective for fingerprinting of tomato genotypes bearing the resistance allele ty-1. the graft-induced infection of begomovirus showed symptoms in the genotypes tested that are in agreement with the results of fingerprinting with the marker ssr-47.
New species emergence via recombination among isolates of the Brazilian tomato infecting Begomovirus complex
Inoue-Nagata, Alice Kazuko;Martin, Darren Patrick;Boiteux, Leonardo Silva;Giordano, Leonardo de Britto;Bezerra, Isabel Cristina;ávila, Antonio Carlos de;
Pesquisa Agropecuária Brasileira , 2006, DOI: 10.1590/S0100-204X2006000800018
Abstract: partial nucleotide sequences of five tomato infecting begomovirus isolates were determined from dna-a fragments, corresponding to the 5' region of the replication associated protein gene, the intergenic region and the 5' region of the coat protein gene. isolate dfm shared 95% identity with tomato mottle leaf curl virus (tmolcv), isolates 34, pa-05, and ta4 were 88% identical to tomato yellow vein streak virus and isolate df-br3 shared 77% identity with tmolcv. recombination analysis indicated that isolate df-br3 was a chimaera, and it provided evidence that there is a complex and actively recombining population of tomato infecting begomoviruses in brazil.
Response of Various Tomato Genotypes to Begomovirus Infection and Its Improved Diagnostic
HAYATI Journal of Biosciences , 2007,
Abstract: Begomovirus infection was identified from tomato growing areas in West Java (Bogor), Central Java (Boyolali), and D.I. Yogyakarta (Kaliurang). Efforts to reduce the infection among others are planting resistance varieties. This research was undertaken to evaluate 14 tomato genotypes for their response to the infection. Dot blot hybridization using nonradioactive (digoxigenin) DNA probe was employed to determine the presence of begomovirus in inoculated plants. Polymerase chain reaction-amplified product of DNA clone of tobacco leaf curl virus –Indonesia was used as a source of DNA probe. All of tomato genotypes evaluated in this study was infected separately by three strain of begomovirus (GVPSlm, GVABy, GVCBgr). Tomato genotypes Bonanza, Jelita, Safira, Permata, Presto, PSPT 8, PSPT 5B, Apel-Belgia, Karibia, Mitra, PSPT 9, Marta, and PSPT 2, showed susceptible or highly susceptible response to the three strains of begomovirus. Exception to those was shown by cv. Intan which resulted in moderate resistance when inoculated with GVCBgr although it resulted susceptible response with the other two strains. Dot-blot hybridization technique was proved to be a powerful tool to detect begomovirus infection in plants showing symptom as well as symptom-less plants. Accumulation of the virus in those plants was relatively high, except in cv. Bonanza and Apel-Belgia. Dot-blot hybridization technique using DIG-labeled DNA probe was able to detect begomovirus DNA in infected tissue up to 10-2 dilution factor.
Genetic structure of a Brazilian population of the begomovirus Tomato severe rugose virus (ToSRV)
Jorge González-Aguilera,Sheila S. Tavares,Roberto R. Sobrinho,César A.D. Xavier
Tropical Plant Pathology , 2012, DOI: 10.1590/s1982-56762012000500007
Abstract: Begomoviruses are whitefly-transmitted single-stranded DNA viruses of great economic importance in the tropics and subtropics. Several begomovirus species have been reported in tomatoes in Brazil, but only a few predominate in the field, for unknown reasons. In this study begomovirus-infected tomato samples were collected in Vi osa, State of Minas Gerais, in Nov/2009 and Dec/2010. Viral genomes were amplified, cloned and sequenced. A total of 36 DNA-A components were obtained. Sequence comparisons indicated the presence of a single begomovirus, Tomato severe rugose virus (ToSRV), with pairwise identities between isolates ranging from 97.3 to 100%. Subdivision tests indicated the existence of a single population. The analysis of variability descriptors indicated that the ToSRV population has a genetic variability similar to other begomovirus populations described in Brazil infecting tomato. Neutrality tests suggested the occurrence of purifying selection acting upon the population. Recombination analysis identified recombination events with begomoviruses from the weed species Sida micrantha. The wide distribution of ToSRV in the field and the detection of recombination indicate that continuous monitoring of viral populations in the field will be required to enable an efficient resistance-based control strategy for begomoviruses.
Molecular characterization and construction of an infectious clone of a pepper isolate of Beet curly top Iran virus
Omid Eini; Ghazal Ebadzad-Sahraei; Seyed Ali Akbar Behjatnia
Molecular Biology Research Communications , 2016,
Abstract: Geminiviruses cause curly top disease, in dicotyledonous plants which constrains host crop production. Beet curly top Iran virus (BCTIV) is a widespread Becurtovirus (family Geminiviridae) in numerous areas within Iran. In this study, we isolated and analyzed a full-length genomic DNA of a new variant of BCTIV from pepper crops in the Kaftark region, east of Shiraz (proposed acronym: BCTIV-Kaf [IR: Kaf:2016:Pepper]). Infected pepper plants showed shortening of internodes, severe interveinal chlorosis, upward leaf rolling and leaf curling. Sequence and phylogenetic analysis showed this BCTIV variant grouped with sugar beet isolates of BCTIV and has the highest similarity to a sugar beet BCTIV isolate from Negar town in Kerman province, Iran. It was more distantly related to a bean isolate of BCTIV from northeast region of Iran. A tandem repeat partial dimmer of BCTIV was constructed and found to be infectious in pepper, tomato and Nicotiana benthamiana plants. Results of this study indicated that BCTIV-Kaf is a new variant of BCTIV infecting pepper plants in Shiraz and that geographic location rather than the type of host plant has more effect on genetic diversity of BCTIV in Iran.
PepGMV Rep-Protein Expression in Mammalian Cells
Angela María Chapa-Oliver,Laura Mejía-Teniente,Teresa García-Gasca,Ramon Gerardo Guevara-Gonzalez,Irineo Torres-Pacheco
Viruses , 2012, DOI: 10.3390/v4091792
Abstract: The Geminiviruses genome is a small, single strand DNA that replicates in the plant cell nucleus. Analogous to animal DNA viruses, Geminiviruses depend on the host replication machinery to amplify their genomes and only supply the factors required to?initiate their replication. Consequently, Geminiviruses remove the cell-cycle arrest and?induce the host replication machinery using an endocycle process. They encode proteins,?such as the conserved replication-associated proteins (Rep) that interact with retinoblastoma-like proteins in plants and alter the cell division cycle in yeasts. Therefore, the aim of this work is to analyze the impact of Pepper Golden Mosaic Virus (PepGMV) Rep protein in mammalian cells. Results indicate that the pTracer-SV40:Rep construction obtained in this work can be used to analyze the Rep protein effect in mammalian cells in order to compare the cell cycle regulation mechanisms in plants and animals.
Recombination in Eukaryotic Single Stranded DNA Viruses
Darren P. Martin,Philippe Biagini,Pierre Lefeuvre,Michael Golden,Philippe Roumagnac,Arvind Varsani
Viruses , 2011, DOI: 10.3390/v3091699
Abstract: Although single stranded (ss) DNA viruses that infect humans and their domesticated animals do not generally cause major diseases, the arthropod borne ssDNA viruses of plants do, and as a result seriously constrain food production in most temperate regions of the world. Besides the well known plant and animal-infecting ssDNA viruses, it has recently become apparent through metagenomic surveys of ssDNA molecules that there also exist large numbers of other diverse ssDNA viruses within almost all terrestrial and aquatic environments. The host ranges of these viruses probably span the tree of life and they are likely to be important components of global ecosystems. Various lines of evidence suggest that a pivotal evolutionary process during the generation of this global ssDNA virus diversity has probably been genetic recombination. High rates of homologous recombination, non-homologous recombination and genome component reassortment are known to occur within and between various different ssDNA virus species and we look here at the various roles that these different types of recombination may play, both in?the?day-to-day biology, and in the longer term evolution, of these viruses. We specifically?focus on the ecological, biochemical and selective factors underlying patterns of genetic?exchange detectable amongst the ssDNA viruses and discuss how these should all be?considered when assessing the adaptive value of recombination during ssDNA virus?evolution.
Estudio del transcriptoma en Capsicum chinense Jacq. resistente al virus huasteco vena amarilla del chile
Gasca-González, Ma. Rosario;Rivera-Herrera, Yadira;Torres-Pacheco, Irineo;González-Chavira, Mario M.;Guevara-Olvera, Lorenzo;Mu?oz-Sánchez, Claudia I.;Guevara-González, Ramón G.;
Agrociencia , 2008,
Abstract: in order to enrich the knowledge of transcriptome in incompatible interaction between phyvv and havana chili pepper plants (capsicum chinense jacq.) from the inifap collection denominated bg-3821, the profile of gene expression was studied. these studies are essential for the knowledge at molecular level of signaling mechanisms for mutual recognition and, in its case, the defense response of the host to the pathogen, which may contribute to the design of new crop protection strategies. a differential expression model was used in plants infected by phyvv and subtractive hybridization methodology by suppression (ssh), in order to obtain a library of 99 gene fragments (est), whose expression was specifically induced. the sequence of the obtained est's showed that the genes expressed in this interaction may be grouped in the following categories: a) possible resistance genes; b) genes involved in genetic regulation routes; c) genes with unknown function. by northern-type analysis the differential expression of one est (r100 clone) was confirmed, selected on the basis of its similarity of sequence with genes playing a potential role in resistance mechanisms. with the results of this research, first evidence of genes is presented, that possibly may be involved in recognition and signaling routes in c. chinense in response to phyvv.
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