RESUMO
A southeastern European isolate of Alternanthera mosaic virus (AltMV-MU) of the genus Potexvirus (family Flexiviridae) was purified from the ornamental plant Portulaca grandiflora. The complete nucleotide sequence (6606 nucleotides) of AltMV-MU genomic RNA was defined. The AltMV-MU genome is different from those of all isolates described earlier and is most closely related to genomes of partly sequenced portulaca isolates AltMV-Po (America) and AltMV-It (Italy). Phylogenetic analysis supports the view that AltMV-MU belongs to a new "portulaca" genotype distinguishable from the "phlox" genotype.
Assuntos
Genoma Viral , Folhas de Planta/virologia , Portulaca/virologia , Potexvirus/classificação , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/genética , Dados de Sequência Molecular , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/virologia , Potexvirus/genética , Potexvirus/isolamento & purificação , RNA Viral , RNA Polimerase Dependente de RNA/genéticaRESUMO
A new isolate of Alternantheramosaic virus (AltMV-MU) was purified from Portulaca grandiflora plants. It has been shown that the AltMV-MU coat protein (CP) can be efficiently reassembled in vitro under different conditions into helical RNA-free virus-like particles (VLPs) antigenically related to native virus. The AltMV-MU and VLPs were examined by atomic force and transmission electron microscopies. The encapsidated AltMV-MU RNA is nontranslatable in vitro. However, it can be translationally activated by CP phosphorylation or by binding to the TGB1protein from the virus-coded movement triple gene block.