RESUMO
In Chile, edible herbs are mainly grown by small farmers. This type of horticultural crop typically requires intensive management because it is highly susceptible to insects, some of which transmit viruses that severely affect crop yield and quality. In 2019, in coriander plants tested negative for all previously reported viruses, RNA-Seq analysis of one symptomatic plant revealed a plethora of viruses, including one virus known to infect coriander, five viruses never reported in coriander, and a new cytorhabdovirus with a 14,180 nucleotide RNA genome for which the species name Cytorhabdovirus coriandrum was proposed. Since all the detected viruses were aphid-borne, aphids and weeds commonly growing around the coriander field were screened for viruses. The results showed the occurrence of the same seven viruses and the alfalfa mosaic virus, another aphid-borne virus, in aphids and weeds. Together, our findings document the presence of multiple viruses in coriander and the potential role of weeds as virus reservoirs for aphid acquisition.
Assuntos
Afídeos , Coriandrum , Vírus de Plantas , Vírus , Animais , Chile/epidemiologia , Plantas , Doenças das Plantas , Vírus de Plantas/genéticaRESUMO
The family Potyviridae includes plant viruses with single-stranded, positive-sense RNA genomes of 8-11 kb and flexuous filamentous particles 650-950 nm long and 11-20 nm wide. Genera in the family are distinguished by the host range, genomic features and phylogeny of the member viruses. Most genomes are monopartite, but those of members of the genus Bymovirus are bipartite. Some members cause serious disease epidemics in cultivated plants. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Potyviridae, which is available at ictv.global/report/potyviridae.
Assuntos
Genoma Viral , Filogenia , Doenças das Plantas/virologia , Potyviridae/classificação , Potyviridae/genética , Especificidade de Hospedeiro , Vírus de Plantas/classificação , Vírus de Plantas/genética , Plantas , RNA Viral/genética , Vírion/genética , Vírion/ultraestrutura , Replicação ViralRESUMO
RESUMEN Los potyvirus son uno de los grupos de virus más limitantes en los cultivos de papa (Solanum tuberosum y S. phureja) en el mundo, siendo PVY, PVV y PVA las especies más prevalentes. En este trabajo se evaluó la presencia de estos potyvirus en cuatro lotes de S. tuberosum cv. Diacol-Capiro y cuatro lotes de S. phureja cv. Criolla-Colombia ubicados en el oriente de Antioquia, analizando la cápside viral mediante RT-PCR/secuenciación Sanger y secuenciación de nueva generación (NGS) para S. tuberosum. Los resultados indicaron la ocurrencia de los potyvirus PVY y PVV en las muestras de S. tuberosum y S. phureja, respectivamente; siendo detectadas mediante cebadores específicos la presencia de tres diferentes cepas de PVY (PVYN, PVYNTN y PVY°) en la región de estudio. Este hallazgo fue confirmado por NGS, obteniendo las secuencias completas de los genomas de estas tres cepas, lo que representa el primer reporte de PVYO en Colombia. Por su parte, los análisis de secuencias de la región CP de PVV indicaron niveles de identidad superiores a 99% con respecto a aislamientos del linaje PVVPhu reportado previamente en Antioquia. Estos hallazgos evidencian la necesidad de ajustar los sistemas de detección de virus en los programas de certificación de tubérculo-semilla de papa adelantados en el país.
ABSTRACT Potyviruses are one of the most limiting viruses for the potato (Solanum tuberosum and S. phureja) production worldwide, being PVY, PVV and PVA the most prevalent species. In this work, we tested the presence of these viruses in four commercial S. tuberosum cv. Diacol-Capiro and S. phureja cv. Criolla-Colombia plots in eastern Antioquia using RT-PCR and Sanger sequencing of the coat protein (CP) region, as well as next generation sequencing (NGS) for S. tuberosum samples. Our results revealed the presence of a PVV strain infecting S. phureja with high sequence identity (>99%) to lineage PVVPhu previously reported in Antioquia. Three strains of PVY (PVYN, PVYNTN and PVY°) were found to infect S. tuberosum. The presence of these three PVY strains was confirmed by NGS, allowing the assembly of their complete genomes. This is the first report of the full genome sequence of PVYo strain in Colombia. These findings highlight the need to adjust the tuber-seed certification programs currently implemented in the country.
RESUMO
We describe an automatic segmentation method for polyproteins of the viruses belonging to the Potyviridae family. It uses machine learning techniques in order to predict the cleavage site which define the segments in which said polyproteins are cut in their process of functional maturation. The segmentation application is publicly available for use on a website and it can be accessed through the web service interface too. The prediction models have an average sensitivity of 0.79 and a Matthews correlation coefficient average of 0.23. This method is capable of predicting correctly (coinciding with previously published segmentation) the segmentation of sequences which come from Potyvirus and Rymovirus, genera. However accurate prediction capabilities are affected when faced with either atypical sequences or viruses belonging to less common genera in the Potyviridae family. Future work will focus on establishing greater flexibility in this sense.
RESUMO
ABSTRACT Sixty-seven tulip samples intercepted from the Netherlands by the Brazilian Agriculture Ministry, between 2004 and 2006, and two samples from São Paulo local market, Brazil, were assayed by serological and biological techniques, as well as by electron microscopy observations, for virus screening. In bulbs from the Netherlands potexviruses were detected in five samples and tobamoviruses in other three. Symptoms induced in some differential hosts were similar to those caused by Tobacco mosaic virus (TMV), while serological results indicated an infection byTulip virus X. In two tulip samples from local flower shops, a Potyviridae was identified based on the presence of flexuous particles and cytoplasmic cylindrical inclusions. Mechanical transmission tests to potyvirus hosts in the Amaranthaceae, Chenopodiaceae and Solanaceae species were negative, making possible to exclude a possible infection by Turnip mosaic viru, a common virus species in tulips. Although TVX could be detected in intercepted tulip bulbs from the Netherlands, the virus is only reported in Scotland, Japan and USA.
RESUMO Sessenta e sete amostras de tulipas interceptadas da Holanda pelo Ministério da Agricultura, Pecuária e Abastecimento, entre os anos de 2004 e 2006, e duas amostras, adquiridas no comércio local de São Paulo, foram avaliadas para a presença de vírus por meio de ensaios biológicos, sorológicos e observações ao microscópio eletrônico. Nos bulbos provenientes da Holanda, foram detectados potexvírus em cinco amostras e tobamovírus em duas outras. Os sintomas induzidos em hospedeiras diferenciadoras indicaram a presença de Tobacco mosaic virus (TMV), enquanto que os resultados de testes sorológicos permitiram a identificaçãoo Tulip virus X (TVX). Nas duas amostras adquiridas no comércio local foram detectados Potyviridae, uma vez que partículas alongadoflexuosas e inclusões cilíndricas estavam presentes. Ensaios de transmissão mecânica desses vírus para espécies de Amaranthaceae, Chenopodiaceae e Solanaceae foram negativos, permitindo deste modo ser excluída uma possível infecção pelo Turnip mosaic virus, uma espécie frequente em tulipas. Apesar do TVX ter sido detectado em tulipas interceptadas da Holanda, esse vírus foi relatado apenas na Escócia, Japão e Estados Unidos.