Department of Biological Sciences, University of Lethbridge, Lethbridge, T1K 3M4, Alberta, Canada.
Mutat Res. 2011 May 10;709-710:7-14. doi: 10.1016/j.mrfmmm.2011.02.014. Epub 2011 Mar 3.
We have previously shown that local infection of tobacco plants with tobacco mosaic virus (TMV) or oilseed rape mosaic virus (ORMV) results in a systemic increase in the homologous recombination frequency (HRF). Here, we analyzed what other changes in the genome are triggered by pathogen infection. For the analysis of HRF, mutation frequency (MF) and microsatellite instability (MI), we used three different transgenic Arabidopsis lines carrying β-glucuronidase (GUS)-based substrates in their genome. We found that local infection of Arabidopsis with ORMV resulted in an increase of all three frequencies, albeit to differing degrees. The most prominent increase was observed in microsatellite instability. The increase in HRF was the lowest, although still statistically significant. The analysis of methylation of the 35S promoter and transgene expression showed that the greater instability of the transgene was not attributed to these changes. Strand breaks brought about a significant increase in non-treated tissues of infected plants. The expression of genes associated with various repair processes, such as KU70, RAD51, MSH2, DNA POL α and DNA POL δ, was also increased. To summarize, our data demonstrate that local ORMV infection destabilizes the genome in systemic tissues of Arabidopsis plants in various ways resulting in large rearrangements, point mutations and microsatellite instability.
我们之前曾表明，烟草植物或油菜花叶病毒（TMV）的局部感染导致同源重组频率（HRF）的系统性增加。在这里，我们分析了病原体感染引发的其他基因组变化。为了分析 HRF、突变频率（MF）和微卫星不稳定性（MI），我们使用了三种不同的携带β-葡萄糖醛酸酶（GUS）基底物的转基因拟南芥系。我们发现，油菜花叶病毒在拟南芥中的局部感染导致所有三种频率都增加，尽管增加程度不同。微卫星不稳定性的增加最为显著。HRF 的增加虽然仍然具有统计学意义，但最低。对 35S 启动子和转基因表达的甲基化分析表明，转基因的更大不稳定性并非归因于这些变化。链断裂导致感染植物未处理组织的显着增加。与各种修复过程相关的基因的表达，如 KU70、RAD51、MSH2、DNA POL α 和 DNA POL δ，也增加了。总之，我们的数据表明，局部油菜花叶病毒感染以各种方式使拟南芥植物的系统组织中的基因组不稳定，导致大的重排、点突变和微卫星不稳定性。
