ANNOTATED SEQUENCE RECORD Complete genome sequence of tobacco virus 1, a closterovirus from Nicotiana tabacum Fang Wang 1 • Shuishui Qi 2 • Zhengliang Gao 1 • Ibukun A. Akinyemi 2 • Dafeng Xu 1 • Benguo Zhou 1 Received: 17 August 2015 / Accepted: 19 December 2015 / Published online: 21 January 2016 Ó Springer-Verlag Wien 2016 Abstract The complete genome sequence of a novel virus, provisionally named tobacco virus 1 (TV1), was determined, and this virus was identified in leaves of tobacco (Nicotiana tabacum) exhibiting leaf mosaic and yellowing symptoms in Anhui Province, China. The gen- ome sequence of TV1 consists of 15,395 nucleotides with 61.6 % nucleotide sequence identity to mint virus 1 (MV1). Its genome organization is similar to that of MV1, containing nine open reading frames (ORFs) that poten- tially encode proteins with putative functions in virion assembly, cell-to-cell movement and suppression of RNA silencing. Phylogenetic analysis of the heat shock protein 70 homolog (HSP70h) placed TV1 alongside members of the genus Closterovirus in the family Closteroviridae. To our knowledge, this study is the first report of the complete genome sequence of a closterovirus identified in tobacco. Introduction Tobacco (Nicotiana tabacum) is an economically impor- tant crop worldwide, particularly in China, and its pro- duction is affected by several viruses [14]. Currently, more than 30 viruses belonging to 13 genera of seven families have been reported in tobacco, and infected plants can exhibit symptoms such as mosaic, severe stunting, vein banding, and mottle [7, 10, 22]. Early detection of known viruses and the identification and characterization of novel viruses in tobacco are necessary to develop control measures. The family Closteroviridae includes plant viruses characterized by filamentous particles varying in length from 650 nanometers (nm) to over 2000 nm and a single- stranded positive-sense RNA genome whose size varies from 13 to 19 kilobases. The family Closteroviridae cur- rently has four genera: Closterovirus, Ampelovirus, Crini- virus and Velarivirus [11]. The genus Closterovirus contains well-studied viruses such as beet yellows virus and citrus tristeza virus, among others [11]. Chatzivassiliou et al. reported the first case of a closterovirus isolated from tobacco in Macedonia, Northern Greece. In this study, we identified and characterized the complete genome of a novel virus belonging to a new species in the genus Closterovirus by sequencing small RNAs isolated from symptomatic tobacco plants collected in Anhui Province of China. To our knowledge, this is the first report of the complete genome sequence of a closterovirus identified in tobacco [6]. Plant material and extraction of total RNA from tobacco leaves Leaf samples were collected from several tobacco plants (Nicotiana tabacum) of cultivar Yunyan 87 that were grown in China and showed leaf mosaic and yellowing. Leaf samples with similar symptoms were immediately frozen in liquid nitrogen and stored at -80 °C until RNA extraction. Symptomatic samples were pooled at random for sequencing of sRNAs. Total RNA was extracted from the frozen diseased leaves by homogenization with lysis buffer (50 mM Tris-HCl, pH 8.0; 150 mM LiCl; 5 mM & Benguo Zhou bgzhou@163.com 1 Tobacco Research Institute, Anhui Academy of Agricultural Sciences, Hefei 230031, Anhui, China 2 School of Life Sciences, University of Science and Technology of China, Hefei 230027, Anhui, China 123 Arch Virol (2016) 161:1087–1090 DOI 10.1007/s00705-015-2739-x