ANNOTATED SEQUENCE RECORD Full-length sequence analysis of a distinct isolate of Bidens mottle virus infecting sunflower in Taiwan J. Y. Liao Æ Chung-Chi Hu Æ C. C. Chen Æ C. H. Chang Æ T. C. Deng Received: 24 November 2008 / Accepted: 2 March 2009 / Published online: 24 March 2009 Ó Springer-Verlag 2009 Abstract The full-length genome of a potyvirus, previ- ously known as sunflower chlorotic spot virus isolate SF-1 (SCSV-SF-1) which causes novel symptoms on sunflowers (Helianthus annuus), was sequenced and analyzed. The genome of SCSV-SF-1 is 9,741 nucleotides long, encoding a polyprotein of 3,071 amino acids containing the con- sensus motifs of potyviruses. Sequence comparison revealed that the 3 0 -terminus of SCSV-SF-1 shared over 96% similarities with isolates of Bidens mottle virus (BiMoV). However, SCSV-SF-1 has a very narrow host range, excluding the diagnostic host species for BiMoV, Bidens pilosa and Zinnia elegans. Therefore, SCSV-SF-1 is a distinct isolate of BiMoV. This is the first report of the full-length nucleotide sequence of BiMoV infecting sun- flower in Taiwan. Introduction Sunflowers (Helianthus annuus) showing symptoms of chlorotic ringspot, enation, yellowing and stunting were found in the field in Puli, Taiwan, in 2000. The causal agent was identified to be a new potyvirus, provisionally designated sunflower chlorotic spot virus isolate SF-1 (SCSV-SF-1), based on electron microscopy examination of the morphology of virions and inclusion bodies, elec- trophoresis analysis of the coat protein, and immunological detection by genus- or species-specific mono- or polyclonal antibodies [6]. To elucidate the taxonomy of SCSV-SF-1, the 3 0 -terminal 1,445 nt of the SCSV-SF-1 genome was cloned and sequenced, and subsequently deposited in GenBank under the accession number AF538686 in 2002. Initial database searches performed from 2002 to 2006 using the partial SCSV-SF-1 sequence as the query revealed no known sequences with nucleotide sequence identity higher than 80%. Based on the criteria used for demarcating species in the family Potyviridae [1, 9], the result suggested that SCSV-SF-1 should be a member of a distinct species in the genus Potyvirus. However, recent studies implied that SCSV-SF-1 should be regarded as an isolate of Bidens mottle virus (BiMoV) [2, 10], a currently accepted species of the genus Potyvirus [3], according to comparisons of partial genomic sequen- ces. Nevertheless, there were still concerns over the taxonomic status of SCSV-SF-1: (i) only the 3 0 -terminal sequences of SCSV-SF-1 and two isolates of BiMoV, 620 nt and 1,800 nt for EF467235 [2] and EU078960 [10], respectively, were available for comparison; (ii) the iden- tities of the BiMoV isolates used by Baker et al. [2] or Yousssef et al. [10] were only verified by serological assays, host ranges, and symptomatolgy; and (iii) the phylogenetic analysis raised the possibility that intra- molecular recombination might have occurred in the SCSV-SF-1 genome (unpublished). To address the question concerning the taxonomy status of SCSV-SF-1, the complete genome of SCSV-SF-1 was sequenced in this study, and the coat protein (CP) coding region was used to compare with that of the standard isolate of BiMoV (ATCC-PV165 isolate), which was pur- chased from the American Type Culture Collection J. Y. Liao Á C. C. Chen Á C. H. Chang Á T. C. Deng Division of Plant Pathology, Agricultural Research Institute, Council of Agriculture, Wufeng, Taichung 413, Taiwan, ROC C.-C. Hu (&) Graduate Institute of Biotechnology, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan, ROC e-mail: cchu@dragon.nchu.edu.tw 123 Arch Virol (2009) 154:723–725 DOI 10.1007/s00705-009-0356-2