The extensive genetic diversity of Ralstonia solanacearum, a serious soil-borne phytopathogen, has led to the concept that R. solanacearum encompasses a species complex [R. solanacearum species complex (RSSC)]. Insertion sequences (ISs) are suggested to play an important role in the genome evolution of this pathogen. Here, we identified and analysed transposable elements (TEs), ISs and transposons, in 106 RSSC genomes and 15 Ralstonia spp. We mapped 10 259 IS elements in the complete genome of 62 representative RSSC strains and closely related Ralstonia spp. A unique set of 20 IS families was widespread across the strains, IS5 and IS3 being the most abundant. Our results showed six novel transposon sequences belonging to the Tn3 family carrying passenger genes encoding antibiotic resistance and avirulence proteins. In addition, internal rearrangement events associated with ISs were demonstrated in Ralstonia pseudosolanacearum strains. We also mapped IS elements interrupting avirulence genes, which provided evidence that ISs plays an important role in virulence evolution of RSSC. Additionally, the activity of ISs was demonstrated by transcriptome analysis and DNA hybridization in R. solanacearum isolates. Altogether, we have provided collective data of TEs in RSSC genomes, opening a new path for understanding their evolutionary impact on the genome evolution and diversity of this important plant pathogen.

中文翻译：

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转座因子有助于青枯雷尔氏菌物种复合体的基因组可塑性。

Ralstonia solanacearum是一种严重的土壤传播植物病原体，其广泛的遗传多样性导致了这样一个概念，即R. solanacearum包含一个物种复合体。茄科物种复合体（RSSC）]。建议插入序列（ISs）在这种病原体的基因组进化中起重要作用。在这里，我们鉴定并分析了106个RSSC基因组和15个Ralstonia spp中的转座因子（TEs），IS和转座子。我们在62个代表性RSSC菌株和紧密相关的Ralstonia spp的完整基因组中绘制了10259 IS元素。在菌株中分布了一组独特的20个IS家族，其中IS5和IS3最丰富。我们的研究结果表明，属于Tn3家族的6个新颖的转座子序列带有携带编码抗生素抗性和无毒蛋白的客体基因。此外，在假单胞菌假单胞菌菌株中证实了与IS相关的内部重排事件。我们还绘制了中断无毒力基因的IS元件的图谱，这提供了ISs在RSSC的毒力进化中起重要作用的证据。另外，通过转录组分析和青枯菌分离物中的DNA杂交证明了IS的活性。总之，我们已经提供了RSSC基因组中TE的集体数据，为了解它们对这种重要植物病原体的基因组进化和多样性的进化影响开辟了一条新途径。通过转录组分析和青枯菌分离物的DNA杂交证明了IS的活性。总之，我们提供了RSSC基因组中TE的集体数据，为了解它们对这种重要植物病原体的基因组进化和多样性的进化影响开辟了一条新途径。通过转录组分析和青枯菌分离物的DNA杂交证明了IS的活性。总而言之，我们提供了RSSC基因组中TE的集体数据，为了解它们对这种重要植物病原体的基因组进化和多样性的进化影响开辟了一条新途径。