Liu Likuan, Li Qiwen, Du Jingxuan, Yuan Weibo, Sun Rui, Liu Haoyu, Li Jinping
Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai‒Tibet Plateau, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, China.
Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, Qinghai, China.
PLoS One. 2025 Aug 18;20(8):e0328307. doi: 10.1371/journal.pone.0328307. eCollection 2025.
As a medicinal plant on the Qinghai-Tibet Plateau, Pseudocodon convolvulaceus has garnered significant attention due to its rich medicinal value, demonstrating notable anti-inflammatory and antioxidant activities. To elucidate the characteristics of the chloroplast genome and the phylogenetic position of Pseudocodon convolvulaceus, as well as to explore its genetic structure and evolutionary significance, the complete chloroplast genome was sequenced, assembled, annotated, and compared with the published genomes of the Campanulaceae family. This analysis provides insights into gene content, structural variation, and phylogenetic relationships. A phylogenetic tree was constructed based on the chloroplast genomes of 19 published Campanulaceae species, utilizing two Asteraceae species as outgroups. The results indicated the following: (1) The chloroplast genome of Pseudocodon convolvulaceus is 183,616 bp in length, featuring a typical tetrad structure with a GC content of 38.7%. A total of 134 genes were annotated, comprising 89 protein-coding genes, eight rRNA genes, and 37 tRNA genes, with 12 genes containing one intron and three genes containing two introns. (2) The chloroplast genome includes 67 SSR loci, predominantly single nucleotide repeats, which account for 40% of the total. (3) The genome comprises 64 synonymous codons, including 30 high-frequency codons (RSCU > 1), with 29 of these high-frequency codons ending in A/T, representing 96.7%. This suggests a tendency for high-frequency codons in the chloroplast genome of Pseudocodon convolvulaceus to terminate with A/T. (4) Phylogenetic analysis revealed that Codonopsis minima, Codonopsis lanceolata, Codonopsis pilosula, and Codonopsis tsinlingensis are closely related to Pseudocodon convolvulaceus. The findings of this study enhance our understanding of the genetic basis of this species and its potential applications in drug research, thereby facilitating the use of this genomic resource for conservation strategies and phylogenetic analysis.
作为青藏高原上的一种药用植物，藏鸡蛋参因其丰富的药用价值而备受关注，具有显著的抗炎和抗氧化活性。为了阐明藏鸡蛋参叶绿体基因组的特征及其系统发育位置，以及探索其遗传结构和进化意义，对其完整的叶绿体基因组进行了测序、组装、注释，并与已发表的桔梗科基因组进行了比较。该分析提供了关于基因含量、结构变异和系统发育关系的见解。基于19种已发表的桔梗科物种的叶绿体基因组构建了系统发育树，以两种菊科物种作为外类群。结果表明：（1）藏鸡蛋参的叶绿体基因组长度为183,616 bp，具有典型的四分体结构，GC含量为38.7%。共注释了134个基因，包括89个蛋白质编码基因、8个rRNA基因和37个tRNA基因，其中12个基因含有1个内含子，3个基因含有2个内含子。（2）叶绿体基因组包含67个SSR位点，主要为单核苷酸重复，占总数的40%。（3）该基因组包含64个同义密码子，其中包括30个高频密码子（RSCU > 1），这些高频密码子中有29个以A/T结尾，占96.7%。这表明藏鸡蛋参叶绿体基因组中的高频密码子有以A/T结尾的倾向。（4）系统发育分析表明，薄叶党参、羊乳党参、党参和秦岭党参与藏鸡蛋参密切相关。本研究的结果增进了我们对该物种遗传基础的理解及其在药物研究中的潜在应用，从而有助于利用这一基因组资源制定保护策略和进行系统发育分析。
