RESUMEN
In this study, we describe a novel putative Enamovirus member, Grapevine enamovirus-1 (GEV-1), discovered by high-throughput sequencing (HTS). A limited survey using HTS of 17 grapevines (Vitis spp.) from the south, southeast, and northeast regions of Brazil led to the detection of GEV-1 exclusively on southern plants, infecting four grapevine cultivars (Cabernet Sauvignon, Semillon, CG 90450, and Cabernet franc) with a remarkable identity of around 99% at the nucleotide level. This novel virus was only detected in multiple-virus infected plants exhibiting viral-like symptoms. GEV-1 was also detected on a cv. Malvasia Longa by RT-PCR. We performed graft-transmissibility assays on GEV-1. The organization, products, and cis-acting regulatory elements of GEV-1 genome are also discussed here. The near complete genome sequence of GEV-1 was obtained during the course of this study, lacking only part of the 3' untranslated terminal region. This is the first report of a virus in the family Luteoviridae infecting grapevines. Based on its genomic properties and phylogenetic analyses, GEV-1 should be classified as a new member of the genus Enamovirus.
Asunto(s)
Luteoviridae/genética , Luteoviridae/aislamiento & purificación , Enfermedades de las Plantas/virología , Virus de Plantas/genética , Virus de Plantas/aislamiento & purificación , Vitis/virología , Genoma Viral , Luteoviridae/clasificación , Sistemas de Lectura Abierta , Filogenia , Virus de Plantas/clasificación , Proteínas Virales/genéticaRESUMEN
Yellow dwarf disease, one of the most important diseases of cereal crops worldwide, is caused by virus species belonging to the Luteoviridae family. Forty-two virus isolates obtained from oat (Avena sativa L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), corn (Zea mays L.), and ryegrass (Lolium multiflorum Lam.) collected between 2007 and 2008 from winter cereal crop regions in southern Brazil were screened by polymerase chain reaction (PCR) with primers designed on ORF 3 (coat protein - CP) for the presence of Barley yellow dwarf virus and Cereal yellow dwarf virus (B/CYDV). PCR products of expected size (~357 bp) for subgroup II and (~831 bp) for subgroup I were obtained for three and 39 samples, respectively. These products were cloned and sequenced. The subgroup II 3' partial CP amino acid deduced sequences were identified as BYDV-RMV (92 - 93 % of identity with "Illinois" Z14123 isolate). The complete CP amino acid deduced sequences of subgroup I isolates were confirmed as BYDV-PAV (94 - 99 % of identity) and established a very homogeneous group (identity higher than 99 %). These results support the prevalence of BYDV-PAV in southern Brazil as previously diagnosed by Enzyme-Linked Immunosorbent Assay (ELISA) and suggest that this population is very homogeneous. To our knowledge, this is the first report of BYDV-RMV in Brazil and the first genetic diversity study on B/CYDV in South America.
RESUMEN
Yellow dwarf disease, one of the most important diseases of cereal crops worldwide, is caused by virus species belonging to the Luteoviridae family. Forty-two virus isolates obtained from oat (Avena sativa L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), corn (Zea mays L.), and ryegrass (Lolium multiflorum Lam.) collected between 2007 and 2008 from winter cereal crop regions in southern Brazil were screened by polymerase chain reaction (PCR) with primers designed on ORF 3 (coat protein - CP) for the presence of Barley yellow dwarf virus and Cereal yellow dwarf virus (B/CYDV). PCR products of expected size (~357 bp) for subgroup II and (~831 bp) for subgroup I were obtained for three and 39 samples, respectively. These products were cloned and sequenced. The subgroup II 3' partial CP amino acid deduced sequences were identified as BYDV-RMV (92 - 93 % of identity with "Illinois" Z14123 isolate). The complete CP amino acid deduced sequences of subgroup I isolates were confirmed as BYDV-PAV (94 - 99 % of identity) and established a very homogeneous group (identity higher than 99 %). These results support the prevalence of BYDV-PAV in southern Brazil as previously diagnosed by Enzyme-Linked Immunosorbent Assay (ELISA) and suggest that this population is very homogeneous. To our knowledge, this is the first report of BYDV-RMV in Brazil and the first genetic diversity study on B/CYDV in South America.