School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Mentseekhang, Traditional Tibetan Hospital, Lhasa, Tibet, China.
PLoS One. 2023 Jan 26;18(1):e0281134. doi: 10.1371/journal.pone.0281134. eCollection 2023.
Gentiana crassicaulis and G. straminea are alpine plants of Gentiana with important medicinal value and complex genetic backgrounds. In this study, the mitochondrial genomes (mtDNAs) of these two species were sequenced. The mtDNAs of G. crassicaulis and G. straminea are 368,808 and 410,086 bp long, respectively, 52 and 49 unique genes are annotated in the two species, and the gene arrangement varies widely. Compared to G. crassicaulis, G. straminea loses three effective genes, namely atp6, trnG-GCC and trnV-GAC. As a pseudogene, the atp6 gene of G. straminea is incomplete, which is rare in higher plants. We detected 1696 and 1858 pairs of long repeats and 213 SSRs and 250 SSs in the mtDNAs of G. crassicaulis and G. straminea, respectively. There are 392 SNPs and 18 InDels between the two genomes, and syntenic sequence and structural variation analysis show low collinearity between the two genomes. Chloroplast DNA transferring to mtDNA is observed in both species, and 46,511 and 55,043 bp transferred segments containing three tRNA genes are identified, respectively. Comparative analysis of mtDNAs of G. crassicaulis, G. straminea and four species of Gentianales determined 18 core genes, and there is no specific gene in G. crassicaulis and G. straminea. The phylogenetic tree based on mtDNAs places Gentianaceae in a branch of Gentianales. This study is the first to analyze the mtDNAs of Gentianaceae, which could provide information for analysis of the structure of mtDNAs of higher plants and phylogenetic research of Gentianaceae and Gentianales.
獐牙菜和斜茎獐牙菜是龙胆科獐牙菜属具有重要药用价值的高山植物，具有复杂的遗传背景。本研究对这两个物种的线粒体基因组（mtDNA）进行了测序。獐牙菜和斜茎獐牙菜的 mtDNA 分别长 368808 和 410086bp，两个物种共注释了 52 个和 49 个特有基因，基因排列差异较大。与獐牙菜相比，斜茎獐牙菜丢失了三个有效的基因，即 atp6、trnG-GCC 和 trnV-GAC。atp6 基因作为假基因，斜茎獐牙菜的 atp6 基因不完整，这在高等植物中较为罕见。我们在獐牙菜和斜茎獐牙菜的 mtDNA 中分别检测到 1696 对和 1858 对长重复序列，213 个 SSRs 和 250 个 SSs。两个基因组之间有 392 个 SNPs 和 18 个 InDels，共线性和结构变异分析表明两个基因组之间的同源性较低。在这两个物种中都观察到叶绿体 DNA 转移到 mtDNA 中，分别鉴定出包含三个 tRNA 基因的 46511bp 和 55043bp 的转移片段。对獐牙菜、斜茎獐牙菜和四个龙胆目物种的 mtDNAs 进行比较分析，确定了 18 个核心基因，而獐牙菜和斜茎獐牙菜中没有特定基因。基于 mtDNAs 的系统发育树将龙胆科置于龙胆目分支中。本研究首次分析了龙胆科的 mtDNA，可为高等植物 mtDNA 结构分析和龙胆科及龙胆目系统发育研究提供信息。
