RESUMO
The phylum Cressdnaviricota comprises viruses with single-stranded, circular DNA genomes that encode an HUH-type endonuclease (known as Rep). The phylum includes two classes, eight orders, and 11 families. Here, we report the creation of a twelfth family in the order Mulpavirales, class Arfiviricetes of the phylum Cressdnaviricota. The family Amesuviridae comprises viruses that infect plants and is divided into two genera: Temfrudevirus, including the species Temfrudevirus temperatum (with temperate fruit decay-associated virus as a member), and Yermavirus, including the species Yermavirus ilicis (with yerba mate-associated circular DNA virus as a member). Both viruses encode Rep proteins with HUH endonuclease and SH3 superfamily helicase domains. Phylogenetic analysis indicates that the replicative module of amesuviruses constitutes a well-supported monophyletic clade related to Rep proteins from viruses in the order Mulpavirales. Furthermore, both viruses encode a single capsid protein (CP) related to geminivirus CPs. Phylogenetic incongruence between the replicative and structural modules of amesuviruses suggests a chimeric origin resulting from remote recombination events between ancestral mulpavirales and geminivirids. The creation of the family Amesuviridae has been ratified by the International Committee on Taxonomy of Viruses (ICTV).
Assuntos
Vírus de DNA , Vírus de Plantas , Vírus de DNA/classificação , Vírus de DNA/isolamento & purificação , DNA Circular/genética , DNA de Cadeia Simples/genética , Endonucleases/genética , Geminiviridae/genética , Genoma Viral/genética , Filogenia , Vírus de Plantas/genéticaRESUMO
The genome of a novel rhabdovirus was detected in yerba mate (Ilex paraguariensis St. Hil.). The newly identified virus, tentatively named "yerba mate virus A" (YmVA), has a genome of 14,961 nucleotides. Notably, eight open reading frames were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, including two novel accessory genes, in the order 3'-N-P-3-4-M-G-L-8-5'. Sequence comparisons of the encoded proteins as well as phylogenetic analysis suggest that YmVA is a new member of the genus Cytorhabdovirus, family Rhabdoviridae. YmVA's unique genomic organization and phylogenetic relationships indicate that this virus likely represents a distinct evolutionary lineage among the cytorhabdoviruses.
Assuntos
Ilex paraguariensis/virologia , Doenças das Plantas/virologia , Infecções por Rhabdoviridae/virologia , Rhabdoviridae/classificação , Argentina , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , FilogeniaRESUMO
A single-stranded DNA (ssDNA) virus was detected in Yerba mate samples showing chlorotic linear patterns, chlorotic rings and vein yellowing. The full-genome sequences of six different isolates of this ssDNA circular virus were obtained, which share > 99% sequence identity with each other. The newly identified virus has been tentatively named as yerba mate-associated circular DNA virus (YMaCV). The 2707 nt-long viral genome has two and three open reading frame on its complementary and virion-sense strands, respectively. The coat protein is more similar to that of mastreviruses (44% identity), whereas the replication-associated protein of YMaCV is more similar (49% identity) to that encoded by a recently described, unclassified ssDNA virus isolated on trees in Brazil. This is the first report of a circular DNA virus associated with yerba mate. Its unique genome organization and phylogenetic relationships indicates that YMaCV represents a distinct evolutionary lineage within the ssDNA viruses and therefore this virus should be classified as a member of a new species within an unassigned genus or family.
Assuntos
Vírus de DNA/classificação , Vírus de DNA/isolamento & purificação , DNA de Cadeia Simples/genética , DNA Viral/genética , Genoma Viral/genética , Ilex paraguariensis/virologia , Argentina , Sequência de Bases , Proteínas do Capsídeo/genética , Vírus de DNA/genética , DNA Circular/genética , Fases de Leitura Aberta/genética , Análise de Sequência de DNARESUMO
We investigated the molecular characteristics of an Argentinean isolate of alfalfa leaf curl virus (ALCV-Arg), a virus of the genus Capulavirus in the family Geminiviridae that was isolated from alfalfa plants showing dwarfism. The genome was found to be 2,750 nucleotides in length. In pairwise comparisons, this ALCV isolate shared 83.2% to 92.6% sequence identity with European ALCV isolates. Sequence comparisons and phylogenetic analysis showed that this isolate combines features of strains A and B of ALCV. Recombination analysis showed that ALCV-Arg is a recombinant isolate that was generated by intraspecific recombination between ALCV strains A and B. The results of this study not only show that ALCV-Arg is unique because it combines features of strains A and B but also show that ALCV naturally infects this forage crop on the American continent.
Assuntos
DNA Viral/genética , Geminiviridae/genética , Genoma Viral , Medicago sativa/virologia , Filogenia , Folhas de Planta/virologia , Argentina , Sequência de Bases , Geminiviridae/classificação , Geminiviridae/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Doenças das Plantas/virologia , Recombinação Genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
The complete genome sequence of sunflower ring blotch virus (SuRBV), a previously undescribed potyvirus infecting sunflower in Argentina, is reported. The SuRBV genome comprises 9555 nucleotides (nt) and encodes a polyprotein of 3061 amino acids, flanked by 5' and 3' untranslated regions of 117 and 255 nt, respectively. Phylogenetic analysis showed that SuRBV belongs to the potato virus Y (PVY) subgroup and clusters together with sunflower chlorotic mottle virus and bidens mosaic virus. Percentage nucleotide identity between the whole genomes of SuRBV and BiMV was 70.6%, suggesting SuRBV should be considered a distinct species in the genus Potyvirus.
Assuntos
Genoma Viral , Helianthus/virologia , Doenças das Plantas/virologia , Potyvirus/isolamento & purificação , Regiões 3' não Traduzidas , Argentina , Sequência de Bases , Dados de Sequência Molecular , Filogenia , Potyvirus/classificação , Potyvirus/genética , RNA Viral/genéticaRESUMO
We present the molecular characterization of a new virus infecting yerba mate (Ilex paraguariensis St. Hil.) in Argentina. Deep sequencing of diseased yerba mate plants showing chlorotic linear patterns, chlorotic rings, and vein yellowing resulted in the identification of a new virus resembling plant rhabdoviruses in sequence and genome structure. We have determined the complete genome sequence of this virus, which is 12,876 nt long. Seven open reading frames (ORFs) were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, in the order 3'-N-P-P3-P4-M-G-L-5'. Phylogenetic analysis suggested that the described virus is a new member of the genus Cytorhabdovirus, which was supported by the observation of rhabdovirus-like particles within the cytoplasm of infected yerba mate cells. The virus has been tentatively named "yerba mate chlorosis-associated virus" (YmCaV). The availability of the YmCaV genome sequence will contribute to assessing the genetic variability of this virus and determining its role in this yerba mate disease.
Assuntos
Genoma Viral , Ilex paraguariensis/virologia , Vírus de Plantas/genética , RNA Viral/genética , Rhabdoviridae/genética , Argentina , Citoplasma/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Ilex paraguariensis/citologia , Fases de Leitura Aberta , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Rhabdoviridae/isolamento & purificaçãoRESUMO
Alfalfa dwarf disease, probably caused by synergistic interactions of mixed virus infections, is a major and emergent disease that threatens alfalfa production in Argentina. Deep sequencing of diseased alfalfa plant samples from the central region of Argentina resulted in the identification of a new virus genome resembling enamoviruses in sequence and genome structure. Phylogenetic analysis suggests that it is a new member of the genus Enamovirus, family Luteoviridae. The virus is tentatively named "alfalfa enamovirus 1" (AEV-1). The availability of the AEV-1 genome sequence will make it possible to assess the genetic variability of this virus and to construct an infectious clone to investigate its role in alfalfa dwarfism disease.
Assuntos
Genoma Viral , Luteoviridae/genética , Medicago sativa/virologia , Doenças das Plantas/virologia , Argentina , Sequência de Bases , Luteoviridae/classificação , Luteoviridae/isolamento & purificação , Dados de Sequência Molecular , Fases de Leitura Aberta , FilogeniaRESUMO
Groundnut ringspot virus (GRSV) and tomato chlorotic spot virus (TCSV) share biological and serological properties, so their identification is carried out by molecular methods. Their genomes consist of three segmented RNAs: L, M and S. The finding of a reassortant between these two viruses may complicate correct virus identification and requires the characterization of the complete genome. Therefore, we present for the first time the complete sequences of all the genes encoded by a GRSV isolate. The high level of sequence similarity between GRSV and TCSV (over 90 % identity) observed in the genes and proteins encoded in the M RNA support previous results indicating that these viruses probably have a common ancestor.
Assuntos
Genoma Viral , Doenças das Plantas/virologia , Tospovirus/genética , Sequência de Bases , Genômica , Solanum lycopersicum/virologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , RNA Viral/genética , Tospovirus/classificação , Tospovirus/isolamento & purificação , Proteínas Virais/genéticaRESUMO
The complete nucleotide sequence of an Alfalfa mosaic virus (AMV) isolate infecting alfalfa (Medicago sativa L.) in Argentina, AMV-Arg, was determined. The virus genome has the typical organization described for AMV, and comprises 3,643, 2,593, and 2,038 nucleotides for RNA1, 2 and 3, respectively. The whole genome sequence and each encoding region were compared with those of other four isolates that have been completely sequenced from China, Italy, Spain and USA. The nucleotide identity percentages ranged from 95.9 to 99.1 % for the three RNAs and from 93.7 to 99 % for the protein 1 (P1), protein 2 (P2), movement protein and coat protein (CP) encoding regions, whereas the amino acid identity percentages of these proteins ranged from 93.4 to 99.5 %, the lowest value corresponding to P2. CP sequences of AMV-Arg were compared with those of other 25 available isolates, and the phylogenetic analysis based on the CP gene was carried out. The highest percentage of nucleotide sequence identity of the CP gene was 98.3 % with a Chinese isolate and 98.6 % at the amino acid level with four isolates, two from Italy, one from Brazil and the remaining one from China. The phylogenetic analysis showed that AMV-Arg is closely related to subgroup I of AMV isolates. To our knowledge, this is the first report of a complete nucleotide sequence of AMV from South America and the first worldwide report of complete nucleotide sequence of AMV isolated from alfalfa as natural host.
Assuntos
Vírus do Mosaico da Alfafa/genética , Vírus do Mosaico da Alfafa/isolamento & purificação , Genoma Viral , Medicago sativa/virologia , Vírus do Mosaico da Alfafa/classificação , Argentina , Sequência de Bases , Dados de Sequência Molecular , Filogenia , Proteínas Virais/genéticaRESUMO
In alfalfa samples analyzed by hightroughput sequencing, four de novo assembled contigs encoding gene products showing identities to alphapartitiviruses proteins were found based on BlastX analysis. The predicted amino acid (aa) sequences of two contigs presented 99-100% identity to the RNA-dependent RNA polymerase (RdRp) and the capsid protein (CP) of the recently reported medicago sativa alphapartitivirus 1 (MsAPV1). In addition, the remaining two contigs shared only 56% (CP) and 70% (RdRp) pairwise aa identity with the proteins of MsAPV1, suggesting that these samples presented also a novel Alphapartitivirus species. Further analyses based on complete genome segments termini and the presence/absence of alphapartitivirus RNA in several samples and public alfalfa RNA datasets corroborated the identification of two different alphapartitivirus members. Our results likely indicate that the reported MsAPV1 genome was previously reconstructed with genome segments of two different alphapartitiviruses. Overall, we not only revisited the MsAPV1 genome sequence but also report a new tentative alphapartitivirus species, which we propose the name medicago sativa alphapartitivirus 2. In addition, the RT-PCR detection of both MsAPV1 and MsAPV2 in several alfalfa cultivars suggests a broad distribution of both viruses.
Assuntos
Genoma Viral , Medicago sativa/virologia , Doenças das Plantas/virologia , Vírus de Plantas/genética , Vírus de RNA/genética , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , Filogenia , Vírus de Plantas/isolamento & purificação , Vírus de RNA/isolamento & purificação , RNA Viral/genética , Proteínas Virais/genéticaRESUMO
Plants of Viola cornuta displaying typical virus symptoms were observed during spring 2003 in a plant nursery in Córdoba, central Argentina. Electron microscopic examinations of symptomatic leaf samples revealed the presence of isometric virus-like particles about 30 nm in diameter. Subsequent serological analysis allowed the identification of the pathogen as a subgroup I strain of Cucumber mosaic virus (CMV). These results were confirmed by antigen capture--reverse transcription--polymerase chain reaction with specific CMV primers, and digestion with a restriction enzyme. This is the first report of CMV infecting V. cornuta in Argentina.
Assuntos
Cucumovirus/genética , Viola/virologia , Doenças Transmissíveis , DNA/química , Infecções , Microscopia Eletrônica , Doenças das Plantas/virologia , RNA Viral/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We have determined the full-length 14,491-nucleotide genome sequence of a new plant rhabdovirus, alfalfa dwarf virus (ADV). Seven open reading frames (ORFs) were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, in the order 3'-N-P-P3-M-G-P6-L-5'. The ORFs are separated by conserved intergenic regions and the genome coding region is flanked by complementary 3' leader and 5' trailer sequences. Phylogenetic analysis of the nucleoprotein amino acid sequence indicated that this alfalfa-infecting rhabdovirus is related to viruses in the genus Cytorhabdovirus. When transiently expressed as GFP fusions in Nicotiana benthamiana leaves, most ADV proteins accumulated in the cell periphery, but unexpectedly P protein was localized exclusively in the nucleus. ADV P protein was shown to have a homotypic, and heterotypic nuclear interactions with N, P3 and M proteins by bimolecular fluorescence complementation. ADV appears unique in that it combines properties of both cytoplasmic and nuclear plant rhabdoviruses.
Assuntos
Genoma Viral , Mapas de Interação de Proteínas , Rhabdoviridae/genética , Proteínas Virais/análise , Núcleo Celular/química , Análise por Conglomerados , Citoplasma/química , DNA Intergênico , Medicago sativa/virologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Nicotiana/virologiaRESUMO
Plants of Viola cornuta displaying typical virus symptoms were observed during spring 2003 in a plant nursery in Córdoba, central Argentina. Electron microscopic examinations of symptomatic leaf samples revealed the presence of isometric virus-like particles about 30 nm in diameter. Subsequent serological analysis allowed the identification of the pathogen as a subgroup 1 strain of Cucumber mosaic virus (CMV). These results were confirmed by antigen capture - reverse transcription - polymerase chain reaction with specific CMV primers, and digestion with a restriction enzyme. This is the first report of CMV infecting V cornuta in Argentina