National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China; Key Lab of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.
Gene. 2019 Apr 30;694:63-70. doi: 10.1016/j.gene.2019.01.026. Epub 2019 Feb 1.
The 35S ribosomal DNA (rDNA) units that occur in tandem repeat are separated by an intergenic spacer (IGS) that plays an important role in rRNA transcription. Moreover, IGS is an important molecular marker for evolutionary research in plants. In the present study, the IGS sequence of Erianthus arundinaceus was isolated and sequenced for the first time. Structure analysis indicated the entire IGS sequence of three typical E. arundinaceus genotypes was highly conserved, with approximately 3087 bp and 67.1% mean GC content. The putative transcription termination, and initiation sites as well as a large number of methylation sites were found to be present in the IGS of E. arundinaceus compared to other plants. The phylogenic tree constructed using the E. arundinaceus IGS sequence showed that Miscanthus sinensis var. glaber was genetically close to Saccharum spp. while E. arundinaceus was close to Imperata cylindrica. Moreover, fluorescent in situ hybridization revealed that IGS and pTa71 probes had the same locus at nucleolar organizer regions. Taken together, this work enhances our current understanding of the organization of IGS in E. arundinaceus and provides a molecular evidence for an evolutionary relationship between Saccharum spp., E. arundinaceus, I. cylindrica and M. sinensis var. glaber.
35S 核糖体 DNA(rDNA) 单位以串联重复的方式出现，它们之间被基因间间隔区(IGS)隔开，IGS 在 rRNA 转录中起着重要作用。此外，IGS 是植物进化研究的重要分子标记。本研究首次分离并测序了甜根子草的 IGS 序列。结构分析表明，三种典型甜根子草基因型的整个 IGS 序列高度保守，约 3087bp，平均 GC 含量为 67.1%。与其他植物相比，在甜根子草的 IGS 中发现了假定的转录终止和起始位点以及大量的甲基化位点。使用甜根子草 IGS 序列构建的系统发育树表明，荻与糖茅属亲缘关系较近，而甜根子草与白茅亲缘关系较近。此外，荧光原位杂交显示 IGS 和 pTa71 探针在核仁组织区具有相同的位点。总之，这项工作增进了我们对甜根子草 IGS 组织的认识，并为糖茅属、甜根子草、白茅和荻之间的进化关系提供了分子证据。
