Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2003
Publication Date: 2/12/2004
Citation: Nemchinov, L.G., Hammond, J., Jordan, R.L., Hammond, R. 2004. The complete nucleotide sequence, genome organization, and specific detection of beet mosaic virus. Archives of Virology. 149:1201-1204. Interpretive Summary: Beet mosaic virus (BtMV) is a member of the economically important Potyvirus group of plant viruses and infects sugar beet and its close relatives. It is distributed world-wide in all major beet-growing areas and in mixed infections with certain other viruses, causes severe stunting and yield losses on susceptible sugar beet varieties. In this study, we have determined for the first time the complete nucleotide sequence of BtMV genomic RNA and developed a specific molecular means for its diagnosis. The viral genome is 9594 nucleotides in length and codes for a polyprotein of 3086 amino acid residues. The nucleotide and predicted amino acid sequence show that BtMV is most closely related to Peanut mottle virus. Based on the nucleotide sequence, we have developed a BtMV-specific, RT-PCR diagnostic assay that was able to detect the virus in leaf and root samples of sugar beet. The full-length sequence will allow development of virus-resistant plants and a BtMV virus-based transient gene expression vector through the application of gene transformation technologies. The BtMV-specific detection method will be of practical use in early diagnosis and control of BtMV in single and mixed infections.
Technical Abstract: Beet mosaic virus (BtMV) was identified almost five decades ago but has not been fully characterized at the molecular level. In this study, we have determined for the first time the complete nucleotide sequence of BtMV genomic RNA and developed a specific molecular means for its diagnosis. The viral genome of BtMV comprises 9594 nucleotides, excluding the 3' terminal poly (A) sequence, and contains a single open reading frame (ORF) that begins at nt 166 and terminates at nt 9423, encoding a single polyprotein of 3086 amino acid residues. A 3' untranslated region of 171 nucleotides follows the ORF. The deduced genome organization is typical for a member of the family Potyviridae and includes 10 proteins: P1, HC-Pro, P3, 6K1, CI, 6K2, NIa-VPg, NIa-Pro, NIb and coat protein (CP). Nine putative protease cleavage sites were predicted computationally and by analogy with genome arrangements of other potyviruses. Conserved sequence motifs of homologous proteins of other potyviruses were found in corresponding positions of BtMV. BtMV is a distinct species of the genus Potyvirus with the most closely related species being Peanut mottle virus (~55% amino acid identity). Based on the nucleotide sequence obtained, we have developed a virus-specific RT-PCR assay for accurate diagnosis and differentiation of BtMV.