RESUMO
The genome of Banana bunchy top virus (BBTV) consists of six segments of single-stranded DNA of approximately 1 kb in length. We identified and sequenced the complete genomes of two BBTV isolates, one with and one without satellite DNA, from Haikou, Hainan, China. The Haikou-2 isolate contains six genomic segments and an additional satellite DNA while the Haikou-4 isolate contains only six genomic segments. Typical of other babuviruses, each genomic segment encodes a single open reading frame and contains the highly conserved stem-loop and major common regions. Phylogenetic analysis of the two Haikou isolates together with existing sequence records in GenBank confirmed the grouping of BBTV into two large groups and further refined the geographical distribution of each group. To accommodate the changes in the BBTV geographical distribution, the two groups are proposed as the Southeast Asian group and the Pacific-Indian Oceans group. Both the Haikou-2 and Haikou-4 isolates belong to the newly proposed Southeast Asian group.
Assuntos
Babuvirus/genética , Babuvirus/isolamento & purificação , Clonagem Molecular , DNA Viral/química , DNA Viral/genética , Genoma Viral , Babuvirus/classificação , China , Análise por Conglomerados , Dados de Sequência Molecular , Musa/virologia , Filogenia , Doenças das Plantas/virologia , Análise de Sequência de DNARESUMO
Chilli ringspot virus (ChiRSV), a novel potyvirus, was recently found in Hainan, China with high prevalence. The genomic sequence of the ChiRSV-HN/14 isolate was determined by sequencing overlapping cDNA segments generated by reverse transcription polymerase chain reaction with degenerate and/or specific primers. ChiRSV genome (GenBank Acc. no. JN008909) comprised of 9,571 nucleotides (nt) excluding the 3'-terminal poly (A) tail and contained a large open reading frame of 9,240 nt encoding a large polyprotein of 3,079 amino acids with predicted Mr of 349.1 kDa. A small, overlapping PIPO coding region was also found to span from nt 2,913 to 3,095, with a capacity to encode a peptide of 60 amino acids. ChiRSV shares sequence identities of only 48.5-65.4 and 42.9-68.7% with closely related potyviruses at the nucleotide and the amino acid levels, respectively. Phylogenetic analysis of the genomic sequences provided further evidence that ChiRSV is a distinct species of the Potyvirus genus. ChiRSV-HN/14 is most closely related to Tobacco vein banding mosaic virus and two other pepper-infecting potyviruses.