Reaction of lettuce genotypes to Lettuce mosaic virus-Most (LMV-Most) and characterization of the translation factor eIF4E

O objetivo deste trabalho foi avaliar genótipos de alface quanto à reação ao Lettuce mosaic virus (LMV; Most-type, isolado AF-199) e variações no fator eucariótico de tradução eIF4E. Todos os genótipos inoculados foram suscetíveis ao LMV, que foi detectado por RT-PCR com primers específicos. Porém, os acessos 169501, 169501C, 172918A e 162499, apresentaram sintomas tardios e somente nas folhas inoculadas. O sequenciamento da porção codificadora para eIF4E mostrou que estes genótipos apresentam padrão eIF4E0 (mol0), típico para suscetibilidade ao LMV, o que indica que o fenótipo encontrado não está correlacionado com as variações de nucleotídeos neste fator de tradução.The objective of this work was to evaluate lettuce genotypes for their reaction to Lettuce mosaic virus (LMV; Most-type, isolate AF-199) and variations of the eukaryotic translation initiation factor eIF4E. All inoculated genotypes were susceptible to LMV, which was detected by RT-PCR using specific primer pairs. However, the accessions 169501, 169501C, 172918A, and 162499 showed late development of symptoms that appeared only on the inoculated leaves. Sequencing of the coding region of eIF4E showed that these genotypes have an eIF4E0 (mol0) standard typical for their susceptibility to LMV, indicating that the phenotype found is not correlated to nucleotide variations in this translation factor

A aplicação de fungicidas pode incrementar a produção de tomateiro coinfectado por Begomovirus e Crinivirus

The objective of this work was to evaluate the effect of fungicide application on the concentration of Tomato severe rugose virus (ToSRV, Begomovirus) in the 'Mariana' hybrid tomato coinfected with ToSRV and Tomato chlorosis virus (ToCV, Crinivirus) and the progression of viral concentration by qPCR, as well as to quantify fruit yield and quality. Experiment I consisted in the application of fungicides after sowing (pretreatment): pyraclostrobin+metiram (P+M) (at 3 g L-1) + boscalid (B) (at 0.3 g L-1), followed by biweekly sprayings with P+M (4 g L-1); in experiment II, there was no application at sowing (control treatment), only 4 g L-1 P+M biweekly. ToSRV and ToCV transmissions were performed using sweetpotato whiteflies (Bemisia tabaci, biotype B), at 15, 30, 45, 60, and 70 days after transplanting (DAT). There was an increase in yield, better fruit quality, and a reduction in the ToSRV concentration in the plants, when the viruses were transmitted late and pretreatment was performed. Tray pretreatment in sowing with P+M (3 g L-1) and B (0.3 g L-1), followed by biweekly sprayings with P+M (4 g L-1), increases fruit yield and quality in the 'Mariana' hybrid tomato coinfected at 45, 60, and 75 DAT by ToSRV and ToCV, and there is a reduction in the concentration of ToSRV.O objetivo deste trabalho foi avaliar o efeito da aplicação de fungicidas na concentração de Tomato severe rugose virus (ToSRV, Begomovirus) no híbrido de tomateiro 'Mariana' coinfectado por ToSRV e Tomato chlorosis virus (ToCV, Crinivirus) e a progressão da concentração viral por qPCR, bem como quantificar a produção e a qualidade de frutos. O experimento I consistiu na aplicação dos fungicidas após a semeadura (pré-tratamento): piraclostrobina+metiram (P+M) (a 3 g L-1) + boscalida (B) (a 0,3 g L-1), seguida de pulverizações quinzenais com P+M (4 g L-1); no experimento II, não houve aplicação na semeadura (controle), apenas 4 g L-1 de P+M quinzenalmente. As transmissões de ToSRV e ToCV foram realizadas com uso de moscas-brancas (Bemisia tabaci, biótipo B), aos 15, 30, 45, 60 e 70 dias após o transplante (DAT). Houve aumento da produção, melhor qualidade dos frutos e redução da concentração de ToSRV nas plantas, quando os vírus foram transmitidos tardiamente e o pré-tratamento foi realizado. O pré-tratamento na bandeja, na semeadura, com P+M (3 g L-1) e B (0,3 g L-1), seguido de pulverizações quinzenais com P+M (4 g L-1), aumenta a produção e a qualidade dos frutos, em tomateiro híbrido 'Mariana' coinfectado aos 45, 60 e 75 DAT por ToSRV e ToCV, e há redução da concentração de ToSRV

Variabilidade de potyvirus infectando Capsicum spp. no estado de São Paulo

O pimentão (Capsicum annuum L.) está entre as dez hortaliças mais consumidas no Brasil. Dois potyvirus são verificados nesta cultura, o Potato virus Y (PVY) e o Pepper yellow mosaic virus (PepYMV). Foi avaliada entre outubro de 2007 a novembro de 2008, a ocorrência de potyvirus infectando Capsicum spp. nos municípíos de Pirajú, Pirajuí, Paranapanema, Santa Cruz do Rio Pardo, Sorocaba, São Miguel Arcanjo, Itapetininga, Reginópolis, Lins, Iacanga e Mogi-Mirim, do Estado de São Paulo. Das 408 amostras coletadas, 105 foram positivas para a presença de potyvirus utilizando-se antissoro antipotyvirus (Agdia). Em algumas amostras foi detectada a presença de infecção mista com o Cucumber mosaic virus (CMV) e begomovírus. A inoculação de cinqüenta e um isolados na série diferencial de Capsicum spp contendo os genes pvr21, pvr22 e Pvr4, dos quais dez foram provenientes da Empresa Sakata Seed Sudamérica, possibilitou a classificação de dois isolados em patótipo 0, três em patótipo 1, seis em patótipo 1.2, onze em patótipo 1.2.3 e treze em patótipo 1-3 de PVY. Dezesseis isolados não puderam ser classificados em patótipos. Não foi verificada correlação entre local de coleta e ocorrência de um patótipo específico, evidenciando grande variabilidade biológica dos isolados de potyvirus no campo. Nenhum dos isolados coletados ocasionou sintomas evidentes em plantas de pimentão Rubia R e Magali R, indicando que a resistência conferida por estes híbridos ainda é efetiva contra os isolados de potyvirus predominantes no campo. Um par de primers PepNib (5’ GWTSGYYGMMTTGGATGATG 3’) e PepUTR (5’ AGTAGTACAGGAAAAGCC 3’) foi 2 obtido para amplificação completa da região codificadora da proteína capsidial de PVY e PepYMV. Analisando-se esta região do genoma viral, pôde-se constatar predominância da espécie PepYMV. O PVY foi encontrado somente em coletas...The sweet pepper (Capsicum annuum L.) is one of the ten most consumed vegetables in the country. In Brazil, two potyviruses are verified in this culture, the Potato virus Y (PVY) and the Pepper yellow mosaic virus (PepYMV). Between October 2007 and November 2008, the occurrence of potyvirus infecting Capsicum spp. was evaluated on plants collected from Piraju, Pirajuí, Paranapanema, Santa Cruz do Rio Pardo, Sorocaba, São Miguel Arcanjo, Itapetininga, Reginópolis, Lins, Iacanga and Mogi-Mirim, in Sao Paulo State. Among the 408 collected samples, 105 were positive for the presence of potyvirus using antipotyvirus antiserum (Agdia). The presence of mixed infection with the Cucumber mosaic virus (CMV) and begomovirus was also verified. The inoculation of fifty one isolates on the series of Capsicum spp. containing the genes pvr21, pvr22 and Pvr4, ten of them isolates from the Sakata Seed Sudamerica Company, made it possible the classification of these isolates in different pathotypes. Two isolates were classified as pathotype 0, three in pathotype 1, six in 4 pathotype 1.2, eleven in pathotype 1.2.3 and thirteen in pathotype 1.3 of PVY. Sixteen isolates were not able to be classified in pathotypes of PVY. No correlation could be made between the origin of the isolate and the presence of an specific pathotype, indicanting a greet biological variability between the potyvirus isolates. None of the isolates collected in the field caused symptoms in Rubia R and Magali R, indicating that the resistance provided by these hybrids is still effective against the predominant isolates of potyvirus. A pair of primer PepNib (5’ GWTSGYYGMMTTGGATGATG 3’) and PepUTR (5’ AGTAGTACAGGAAAAGCC 3’) were obtained for the complete amplification of the capsid protein region of PVY and PepYMV isolates. PepYMV was the prevalent species of potyvirus found infecting sweet peppers. The PVY was found only... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Potyvirus: caracterização parcial de espécies em plantas daninhas associadas a cultura do pimentão, avaliação de genótipos de alface e análise subcelular do eIF4E e de proteínas do Lettuce mosaic virus

Os potyvírus constituem cerca de 90% das espécies conhecidas da família Potyviridae. No Brasil ocasionam sérios entraves em alface (Lactuca sativa L.) e em pimentão (Capsicum annuum L.), onde se pode citar o Lettuce mosaic virus – LMV e o Pepper yellow mosaic virus (PepYMV), respectivamente. Com o intuito de melhor compreender o reservatório natural de potyvírus em plantas invasoras, amostras foram coletadas em áreas produtoras de pimentão e analisadas utilizando-se antissoro anti-potyvirus (Agdia). Entre estas plantas positivas, destacou-se Solanum americanum Mill, onde foi verificada infecção mista do Cucumber mosaic virus e do Potato virus Y, e Commelina benghalensis L. em que foi encontrado um possível novo potyvírus com a maior identidade de nucleotídeos da proteína capsidial (62%) com a espécie Hardenbergia mosaic virus. Este potyvírus não foi transmitido por extrato vegetal, bem como por afídeos para plantas de pimentão e Nicotiana tabaccum TNN. Na região codificadora para a proteína capsidial do potyvirus não foi encontrado o domínio DAG, relacionado a transmissão por afídeos. Visando encontrar possíveis fontes de resistência ao Lettuce mosaic virus - LMV, genótipos foram inoculados com o isolado LMV-AF-199 (LMV-Most) e o fator de iniciação de tradução eucariótico eIF4E destes genótipos analisado. Em Calona e Salinas-88, conhecidas previamente como portadoras dos genes recessivos mol1 e mol2 foram observados sintomas em todas as plantas inoculadas e verificado o padrão típico do eIF4E1 e eIF4E2, respectivamente...The Potyvirus genus corresponds to 90% of known species of the Potyviridae family. In Brazil potyviruses causes serious problems in lettuce (Lactuca sativa L) and in pepper crops (Capsicum annuum L.), which we can highlight Lettuce mosaic virus – LMV and Pepper yellow mosaic virus (PepYMV), respectively. To increase knowledge about the natural reservoir of potyviruses in weeds, samples were collected from a pepper producer area and analyzed for potyvirus using antiserum anti-potyvirus (Agdia). Solanum americanum Mill was identified as a host for Cucumber mosaic virus and Potato virus Y. In Commelina benghalensis L. a possible new species of potyvirus was found with higher nucleotide identity of the coat protein (62%) with Hardenbergia mosaic virus. This potyvirus could not be transmitted by aphids to sweetpepper and... (Complete abstract click electronic access below

Survey of viruses belonging to different genera and species in noble garlic in Brazil

Garlic (Allium sativumL.) is a host to several viruses, most commonly those belonging to theAllexivirus,Carlavirus, orPotyvirusgenera. Nine species distributed among these three genera have been reported in Brazil: two species within carlaviruses, two within potyviruses, and five within allexiviruses. To quantify the prevalence of these viruses, young leaves from 520 plants (plants either symptomatic or asymptomatic) were collected from commercial fields grown in four Brazilian states and analyzed using universal and species-specific primers via the reverse transcription polymerase chain reaction (RT-PCR). Potyvirus presence was positive in 306 samples (81 %), 151 of them (38 %) in mixed infections with other viruses. The most frequent potyviruses wereOnion yellow dwarf virus(OYDV, 56 %) andLeek yellow stripe virus(LYSV, 55 %). 187 samples (49 %) were positive for allexivirus, with 33 (9 %) showing single infections and 154 (41 %) showing mixed infections withGarlic virus A (GarV-A),Garlic virus B(GarV-B),Garlic virus C(GarV-C),Garlic virus D(GarV-D), and species belonging to theCarlavirus andPotyvirusgenera. The predominant species in which allexiviruses were found were GarV-A and GarV-D. Only 15 samples (4 %) were infected solely by a carlavirus, and 63 (17 %) showed mixed infections with viruses from different genera. The dominant species of carlavirus wasGarlic commom latent virus(GarCLV). Carlaviruses and allexiviruses are frequently associated with mixed infections with potyviruses, whereas mixed infections with carlaviruses and allexiviruses are rare. About 70 % of the plants collected were positive for at least one species of virus

Survey of viruses belonging to different genera and species in noble garlic in Brazil

Garlic (Allium sativumL.) is a host to several viruses, most commonly those belonging to theAllexivirus,Carlavirus, orPotyvirusgenera. Nine species distributed among these three genera have been reported in Brazil: two species within carlaviruses, two within potyviruses, and five within allexiviruses. To quantify the prevalence of these viruses, young leaves from 520 plants (plants either symptomatic or asymptomatic) were collected from commercial fields grown in four Brazilian states and analyzed using universal and species-specific primers via the reverse transcription polymerase chain reaction (RT-PCR). Potyvirus presence was positive in 306 samples (81 %), 151 of them (38 %) in mixed infections with other viruses. The most frequent potyviruses wereOnion yellow dwarf virus(OYDV, 56 %) andLeek yellow stripe virus(LYSV, 55 %). 187 samples (49 %) were positive for allexivirus, with 33 (9 %) showing single infections and 154 (41 %) showing mixed infections withGarlic virus A (GarV-A),Garlic virus B(GarV-B),Garlic virus C(GarV-C),Garlic virus D(GarV-D), and species belonging to theCarlavirus andPotyvirusgenera. The predominant species in which allexiviruses were found were GarV-A and GarV-D. Only 15 samples (4 %) were infected solely by a carlavirus, and 63 (17 %) showed mixed infections with viruses from different genera. The dominant species of carlavirus wasGarlic commom latent virus(GarCLV). Carlaviruses and allexiviruses are frequently associated with mixed infections with potyviruses, whereas mixed infections with carlaviruses and allexiviruses are rare. About 70 % of the plants collected were positive for at least one species of virus

Reaction of lettuce genotypes to Lettuce mosaic virus-Most (LMV-Most) and characterization of the translation factor eIF4E

<div><p>Abstract: The objective of this work was to evaluate lettuce genotypes for their reaction to Lettuce mosaic virus (LMV; Most-type, isolate AF-199) and variations of the eukaryotic translation initiation factor eIF4E. All inoculated genotypes were susceptible to LMV, which was detected by RT-PCR using specific primer pairs. However, the accessions 169501, 169501C, 172918A, and 162499 showed late development of symptoms that appeared only on the inoculated leaves. Sequencing of the coding region of eIF4E showed that these genotypes have an eIF4E0 (mol 0 ) standard typical for their susceptibility to LMV, indicating that the phenotype found is not correlated to nucleotide variations in this translation factor.</p></div