College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at Landscape Architecture and Arts, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Int J Mol Sci. 2023 Oct 17;24(20):15263. doi: 10.3390/ijms242015263.
The Elsholtzieae, comprising ca. 7 genera and 70 species, is a small tribe of Lamiaceae (mint family). Members of Elsholtzieae are of high medicinal, aromatic, culinary, and ornamentals value. Despite the rich diversity and value of Elsholtzieae, few molecular markers or plastomes are available for phylogenetics. In the present study, we employed high-throughput sequencing to assemble two plastomes, and , for the first time, and compared with other plastomes of Elsholtzieae. The plastomes of Elsholtzieae exhibited a quadripartite structure, ranging in size from 148,288 bp to 152,602 bp. Excepting the absence of the pseudogene in , the exhaustive tally revealed the presence of 132 genes (113 unique genes). Among these, 85 protein-coding genes (CDS), 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes ( and ) were annotated. Comparative analyses showed that the plastomes of these species have minor variations at the gene level. Notably, the plastid genome exhibited increased GC content regions in the LSC and SSC, resulting in an increased overall GC content of the entire plastid genome. The plastid genome displayed modified boundaries due to inverted repeat (IR) contraction. The sequences of CDS and intergenic regions (IGS) with elevated variability were identified as potential molecular markers for taxonomic inquiries within Elsholtzieae. Phylogenetic analysis indicated that four genera formed monophyletic entities, with and forming a sister clade. This clade was, in turn, sister to , collectively forming a sister group to . Both CDS, and CDS + IGS could construct a phylogenetic tree with stronger support. These findings facilitate species identification and DNA barcoding investigations in Elsholtzieae and provide a foundation for further exploration and resource utilization within this tribe.
Elsholtzieae 包括大约 7 个属和 70 个种，是唇形科（薄荷科）的一个小部落。Elsholtzieae 的成员具有很高的药用、芳香、烹饪和观赏价值。尽管 Elsholtzieae 具有丰富的多样性和价值，但用于系统发育的分子标记或质体基因组很少。在本研究中，我们首次采用高通量测序组装了两个质体基因组， 和 ，并与 Elsholtzieae 的其他质体基因组进行了比较。Elsholtzieae 的质体基因组呈现出四分体结构，大小从 148288bp 到 152602bp 不等。除了 缺失假基因 外，详尽的统计显示存在 132 个基因（113 个独特基因）。其中，85 个蛋白质编码基因（CDS）、37 个 tRNA 基因、8 个 rRNA 基因和 2 个假基因（ 和 ）被注释。比较分析表明，这些物种的质体基因组在基因水平上存在较小的变异。值得注意的是， 质体基因组在 LSC 和 SSC 中表现出增加的 GC 含量区，导致整个质体基因组的总 GC 含量增加。质体基因组由于反向重复（IR）收缩而显示出修饰的边界。CDS 和基因间区（IGS）的序列具有较高的变异性，被鉴定为 Elsholtzieae 分类学研究的潜在分子标记。系统发育分析表明，四个属形成单系实体， 和 形成姐妹分支。这个分支反过来又是 的姐妹分支，共同形成 的姐妹群。CDS 和 CDS + IGS 都可以构建具有更强支持的系统发育树。这些发现有助于 Elsholtzieae 中的物种鉴定和 DNA 条形码研究，并为进一步探索和利用该部落提供了基础。
