Navarro J A, Torok V A, Vetten H J, Pallas V
Instituto de Biología Molecular y Celular de Plantas, IBMCP, Universidad Politecnica de Valencia-CSIC, Valencia, Spain.
Arch Virol. 2005 Apr;150(4):681-94. doi: 10.1007/s00705-004-0456-y. Epub 2004 Dec 21.
Available data suggests that lettuce big-vein disease is caused by the ophiovirus Mirafiori lettuce big-vein virus (MLBVV) but not by the varicosavirus Lettuce big-vein-associated virus (LBVaV), although the latter is frequently associated with the disease. Since the disease occurs worldwide, the putative coat protein (CP) open reading frames of geographically distinct isolates of MLBVV and LBVaV were sequenced. Comparison of both nucleotide and amino acid sequences showed a high level of sequence similarity among LBVaV isolates. Phylogenetic analysis of LBVaV CP nucleotide sequences showed that most of the Spanish isolates clustered in a phylogenetic group whereas English isolates were more similar to the USA isolate. An Australian isolate was closely related to the Dutch isolate. Genetic diversity among MLBVV CP nucleotide sequences was higher ranging from 0.2% to 12%. Phylogenetic analysis of MLBVV CP nucleotide sequences revealed two distinct subgroups. However, this grouping was not correlated with symptom development on lettuce or the geographic origin of the MLBVV isolates. Finally, a quick method based on RFLP analysis of RT-PCR amplicons was developed for assigning MLBVV isolates to the two subgroups.
现有数据表明，生菜大脉病是由蛇形病毒米拉弗洛里生菜大脉病毒（MLBVV）引起的，而非由静脉曲张病毒生菜大脉相关病毒（LBVaV）引起，尽管后者常与该病相关。由于该病在全球范围内发生，因此对来自不同地理区域的MLBVV和LBVaV分离株的假定衣壳蛋白（CP）开放阅读框进行了测序。核苷酸和氨基酸序列比较显示，LBVaV分离株之间具有高度的序列相似性。对LBVaV CP核苷酸序列的系统发育分析表明，大多数西班牙分离株聚集在一个系统发育组中，而英国分离株与美国分离株更为相似。一个澳大利亚分离株与荷兰分离株密切相关。MLBVV CP核苷酸序列之间的遗传多样性更高，范围为0.2%至12%。对MLBVV CP核苷酸序列的系统发育分析揭示了两个不同的亚组。然而，这种分组与生菜上的症状发展或MLBVV分离株的地理来源无关。最后，开发了一种基于RT-PCR扩增产物RFLP分析的快速方法，用于将MLBVV分离株分为两个亚组。
