Bag S, Druffel K L, Salewsky T, Pappu H R
Department of Plant Pathology, Washington State University, Pullman, 99164, USA.
Arch Virol. 2009;154(4):715-8. doi: 10.1007/s00705-009-0349-1. Epub 2009 Mar 15.
Iris yellow spot tospovirus (IYSV) of the family Bunyaviridae causes a serious disease in onion in the USA and other parts of the world. Inspite of its economic importance, the complete genomic sequence of IYSV from the USA is not available. The genome structure and organization of the medium (M) RNA of a Washington (WA) isolate of IYSV were determined and compared to the corresponding region of two isolates previously described from Brazil and The Netherlands. Sequence analysis showed that the M-RNA was 4,817 nucleotides long and potentially coded for the movement protein (NSm) in the viral sense and the glycoprotein precursor (Gn and Gc) in the viral complementary sense. The predicted sizes of NSm and Gn/Gc precursor were 34.7 and 128.84 kDa, respectively. The two open reading frames are separated by a 380 nucleotide intergenic region. Phylogenetic analysis of the NSm and Gn/Gc genes from the WA isolate showed grouping that reflected their respective serogroups. The WA isolate formed a close cluster with the two previously reported IYSV isolates and the IYSV cluster was distinguishable from other tospovirus species. This is the first report of complete genomic sequence of the M-RNA of IYSV from the US.
布尼亚病毒科的鸢尾黄斑番茄斑萎病毒（IYSV）在美国及世界其他地区的洋葱上引发严重病害。尽管其具有经济重要性，但来自美国的IYSV完整基因组序列尚未可得。对一株华盛顿（WA）分离株的IYSV中（M）RNA的基因组结构和组织进行了测定，并与先前从巴西和荷兰描述的两个分离株的相应区域进行了比较。序列分析表明，M-RNA长4817个核苷酸，在病毒正义链上可能编码运动蛋白（NSm），在病毒互补链上编码糖蛋白前体（Gn和Gc）。预测的NSm和Gn/Gc前体大小分别为34.7 kDa和128.84 kDa。两个开放阅读框由一个380个核苷酸的基因间隔区隔开。对WA分离株的NSm和Gn/Gc基因进行的系统发育分析显示，分组反映了它们各自的血清群。WA分离株与之前报道的两个IYSV分离株形成了一个紧密的聚类，并且IYSV聚类与其他番茄斑萎病毒种有明显区别。这是来自美国的IYSV M-RNA完整基因组序列的首次报道。
