Chen J, MacFarlane S A, Wilson T M
Department of Virology, Scottish Crop Research Institute, Invergowrie, Dundee, United Kingdom.
Virology. 1994 Aug 1;202(2):921-9. doi: 10.1006/viro.1994.1414.
Repeated passage of soil-borne wheat mosaic virus (SBWMV; wild-type Oklahoma field isolate; designated Okl-0) by manual inoculation resulted in deletion of part of SBWMV RNA2. Deletion was apparent in the population of RNA2 molecules after only 11 weeks in primary inoculated wheat plants (called Okl-1) and after 5 passages (Okl-5; 20 weeks) no full-length RNA2 remained. The extent of deletion in the Oklahoma isolate was compared with that in the previously studied Lab 1 (Nebraska) isolate. RNA2 from Okl-1, Okl-7, and Lab 1 were analyzed by RT-PCR amplification using sets of primer pairs which spanned all portions of the intact molecule. Lab 1 and the new stable isolate, Okl-7, were found to be deleted for 1058 and 759 nt, respectively, within the region encoding the coat protein-readthrough domain. However, the Okl-7 deletion was in a different position from the Lab 1 deletion. This suggests that deletions of SBWMV RNA2 which occur during serial manual inoculation are not directed toward production of a conserved, truncated form of the 84-kDa extended coat protein, but might reflect an RNA sequence-dependent event.
通过人工接种反复传代土壤传播的小麦花叶病毒（SBWMV；野生型俄克拉荷马田间分离株；命名为Okl-0）导致SBWMV RNA2的一部分缺失。在初次接种的小麦植株中仅11周后（称为Okl-1），RNA2分子群体中就明显出现了缺失，经过5次传代（Okl-5；20周）后，不再有全长RNA2留存。将俄克拉荷马分离株的缺失程度与之前研究的实验室1（内布拉斯加）分离株进行了比较。使用跨越完整分子所有部分的引物对，通过RT-PCR扩增分析了来自Okl-1、Okl-7和实验室1的RNA2。发现实验室1和新的稳定分离株Okl-7在编码外壳蛋白通读结构域的区域内分别缺失了1058和759个核苷酸。然而，Okl-7的缺失位置与实验室1的缺失位置不同。这表明在连续人工接种过程中发生的SBWMV RNA2缺失并非针对产生84 kDa延伸外壳蛋白的保守截短形式，而是可能反映了一个RNA序列依赖性事件。
