Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Mais filtros

Base de dados
Intervalo de ano de publicação
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33433311


Nanoviridae is a family of plant viruses (nanovirids) whose members have small isometric virions and multipartite, circular, single-stranded (css) DNA genomes. Each of the six (genus Babuvirus) or eight (genus Nanovirus) genomic DNAs is 0.9-1.1 kb and is separately encapsidated. Many isolates are associated with satellite-like cssDNAs (alphasatellites) of 1.0-1.1 kb. Hosts are eudicots, predominantly legumes (genus Nanovirus), and monocotyledons, predominantly in the order Zingiberales (genus Babuvirus). Nanovirids require a virus-encoded helper factor for transmission by aphids in a circulative, non-propagative manner. This is a summary of the ICTV Report on the family Nanoviridae, which is available at

Nanoviridae/classificação , Nanoviridae/fisiologia , Animais , Afídeos/virologia , Babuvirus/classificação , Babuvirus/genética , Babuvirus/fisiologia , Babuvirus/ultraestrutura , DNA Viral/genética , Fabaceae/virologia , Genoma Viral , Insetos Vetores/virologia , Nanoviridae/genética , Nanoviridae/ultraestrutura , Nanovirus/classificação , Nanovirus/genética , Nanovirus/fisiologia , Nanovirus/ultraestrutura , Doenças das Plantas/virologia , Proteínas Virais/genética , Vírion/ultraestrutura , Replicação Viral , Zingiberales/virologia
Annu Rev Entomol ; 66: 389-405, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32931313


Of the approximately 1,200 plant virus species that have been described to date, nearly one-third are single-stranded DNA (ssDNA) viruses, and all are transmitted by insect vectors. However, most studies of vector transmission of plant viruses have focused on RNA viruses. All known plant ssDNA viruses belong to two economically important families, Geminiviridae and Nanoviridae, and in recent years, there have been increased efforts to understand whether they have evolved similar relationships with their respective insect vectors. This review describes the current understanding of ssDNA virus-vector interactions, including how these viruses cross insect vector cellular barriers, the responses of vectors to virus circulation, the possible existence of viral replication within insect vectors, and the three-way virus-vector-plant interactions. Despite recent breakthroughs in our understanding of these viruses, many aspects of plant ssDNA virus transmission remain elusive. More effort is needed to identify insect proteins that mediate the transmission of plant ssDNA viruses and to understand the complex virus-insect-plant three-way interactions in the field during natural infection.

DNA de Cadeia Simples , Geminiviridae , Insetos Vetores , Insetos , Nanoviridae , Animais , Plantas/virologia
J Gen Virol ; 95(Pt 5): 1178-1191, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24515973


The recent identification of a new nanovirus, pea necrotic yellow dwarf virus, from pea in Germany prompted us to survey wild and cultivated legumes for nanovirus infections in several European countries. This led to the identification of two new nanoviruses: black medic leaf roll virus (BMLRV) and pea yellow stunt virus (PYSV), each considered a putative new species. The complete genomes of a PYSV isolate from Austria and three BMLRV isolates from Austria, Azerbaijan and Sweden were sequenced. In addition, the genomes of five isolates of faba bean necrotic yellows virus (FBNYV) from Azerbaijan and Spain and those of four faba bean necrotic stunt virus (FBNSV) isolates from Azerbaijan were completely sequenced, leading to the first identification of FBNSV occurring in Europe. Sequence analyses uncovered evolutionary relationships, extensive reassortment and potential remnants of mixed nanovirus infections, as well as intra- and intercomponent recombination events within the nanovirus genomes. In some virus isolates, diverse types of the same genome component (paralogues) were observed, a type of genome complexity not described previously for any member of the family Nanoviridae. Moreover, infectious and aphid-transmissible nanoviruses from cloned genomic DNAs of FBNYV and BMLRV were reconstituted that, for the first time, allow experimental reassortments for studying the genome functions and evolution of these nanoviruses.

Variação Genética , Genoma Viral , Nanoviridae/classificação , Nanoviridae/genética , Recombinação Genética , Análise de Sequência de DNA , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , Europa (Continente) , Evolução Molecular , Fabaceae/virologia , Dados de Sequência Molecular , Nanoviridae/isolamento & purificação , Filogenia , Doenças das Plantas/virologia
Int J Mol Sci ; 14(8): 15233-59, 2013 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-23887650


Plants infected with DNA viruses produce massive quantities of virus-derived, 24-nucleotide short interfering RNAs (siRNAs), which can potentially direct viral DNA methylation and transcriptional silencing. However, growing evidence indicates that the circular double-stranded DNA accumulating in the nucleus for Pol II-mediated transcription of viral genes is not methylated. Hence, DNA viruses most likely evade or suppress RNA-directed DNA methylation. This review describes the specialized mechanisms of replication and silencing evasion evolved by geminiviruses and pararetoviruses, which rescue viral DNA from repressive methylation and interfere with transcriptional and post-transcriptional silencing of viral genes.

Caulimoviridae/genética , Metilação de DNA/genética , Geminiviridae/genética , Doenças das Plantas/imunologia , RNA Interferente Pequeno/metabolismo , Caulimoviridae/metabolismo , Geminiviridae/metabolismo , Nanoviridae/genética , Nanoviridae/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/virologia , Plantas/genética , Plantas/imunologia , Interferência de RNA/imunologia
Virus Res ; 177(1): 98-102, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23816604


Circulative plant viruses such as luteovirids and geminiviruses have been shown to bind to GroEL proteins produced by endosymbiotic bacteria harboured within hemipteran vectors. These interactions seem to prevent the degradation of the viral particles in the aphid's haemocoel. Similarly to luteovirids and geminiviruses, Banana bunchy top virus (BBTV), a member of the Nanoviridae family, is transmitted in a persistent, circulative manner and can be detected in the haemolymph of the aphid vector, Pentalonia nigronervosa. To date, it is not known if BBTV can interact with GroEL. In this study, we localised and inferred the phylogeny of a Buchnera aphidicola endosymbiont inhabiting P. nigronervosa. Furthermore, we predicted the 3D structure of Buchnera GroEL and detected the protein in the haemolymph of P. nigronervosa. Interactions were tested using 3 different assays: immunocapture PCR, dot blot, and far-western blot assays; however, none of them showed evidence of a BBTV-GroEL interaction. We concluded that it was unlikely that BBTV interacted with Buchnera GroEL either in vitro or in vivo and we discuss possible alternatives by which BBTV viral particles are able to avoid the process of degradation in the aphid haemocoel.

Afídeos/microbiologia , Proteínas de Bactérias/metabolismo , Buchnera/metabolismo , Chaperonina 60/metabolismo , Musa/virologia , Nanoviridae/metabolismo , Doenças das Plantas/virologia , Animais , Afídeos/virologia , Proteínas de Bactérias/genética , Buchnera/classificação , Buchnera/genética , Buchnera/isolamento & purificação , Chaperonina 60/genética , Insetos Vetores/microbiologia , Insetos Vetores/virologia , Nanoviridae/genética