Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Northeast Forestry University, Harbin, 150040, China.
Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin, 150040, China.
Mol Biol Rep. 2023 Jan;50(1):665-677. doi: 10.1007/s11033-022-08004-w. Epub 2022 Nov 12.
By the time our study was completed, the chloroplast genomes of Syringa oblata, S. pubescents subsp. Microphylla, and S. reticulate subsp. Amurensis had not been sequenced, and their genetic background was not clear.
In this study, the chloroplast genomes of Syringa oblata, S. pubescents subsp. Microphylla, S. reticulate subsp. Amurensis, and five other species of Syringa were sequenced for a comparative genomics analysis, inverted repeat (IR) boundary analysis, collinearity analysis, codon preference analysis and a nucleotide variability analysis. Differences in the complete chloroplast genomes of 30 species of Oleaceae were compared with that of S. oblata as the reference species, and Ginkgo biloba was used as the out group to construct the phylogenetic tree.
The results showed that the chloroplast genomes of S. oblata, S. pubescents subsp. Microphylla, and S. reticulate subsp. Amurensis were similar to those of other angiosperms and showed a typical four-segment structure, with full lengths of 155,569, 160,491, 155,419, and protein codes of 88, 95, and 87, respectively. Because the IR boundary of S. pubescents subsp. Microphylla was significantly expanded to the large single copy (LSC) region, resulting in complete replication of some genes in the IR region, the LSC region of S. pubescents subsp. Microphylla was significantly shorter than those of S. oblate and S. reticulate subsp. Amurensis. Similar to most higher plants, these three species have a preference for their codons ending with A/T.
We consider the genus Syringa to be a synphyletic group. The nucleotide variability and phylogenetic analyses showed that Syringa differentiated before Ligustrum and Ligustrum developed from Syringa. We propose removing the existing section division and directly dividing Syringa into five series.
在我们的研究完成时，紫丁香、毛丁香亚种、紫丁香亚种的叶绿体基因组尚未测序，其遗传背景尚不清楚。
本研究对紫丁香、毛丁香亚种、紫丁香亚种以及其他 5 种丁香属植物的叶绿体基因组进行了测序，进行了比较基因组分析、反向重复（IR）边界分析、共线性分析、密码子偏好分析和核苷酸变异分析。将 30 种木犀科植物的完整叶绿体基因组与作为参考物种的紫丁香进行比较，以银杏作为外群构建系统发育树。
结果表明，紫丁香、毛丁香亚种和紫丁香亚种的叶绿体基因组与其他被子植物相似，表现出典型的四段结构，全长分别为 155569、160491 和 155419，蛋白质编码分别为 88、95 和 87。由于毛丁香亚种的 IR 边界显著扩展到大片段重复（LSC）区，导致 IR 区的一些基因完全复制，毛丁香亚种的 LSC 区明显短于紫丁香和紫丁香亚种。与大多数高等植物一样，这三个物种的密码子偏好以 A/T 结尾。
我们认为丁香属是一个并系群。核苷酸变异和系统发育分析表明，丁香属在女贞属分化之前就已经分化，女贞属是由丁香属进化而来的。我们建议取消现有的分组，直接将丁香属分为五个系列。
