■Acronema属,属于伞形科,包括大约25种分布在从尼泊尔东部到中国西南部的高海拔中国-喜马拉雅地区。该属是一个分类学上复杂的属,通常具有模糊的物种边界,并且与Sinocarum和其他紧密属的通用定界有问题,主要是由于不同的形态特征。
■为了探索系统发育关系并阐明Acronema属及其相关属的限制,我们基于两个分子数据集(质体数据和ITS序列)重建了具有高支持度和分辨率的可靠系统发育框架,并进行了形态学分析.
■两种系统发育分析都有力地支持Acronema是一个非单系群体,分为两个分支:AcronemaClade和东亚Clade。我们还对16个Acronema完整的质体进行了新的测序和组装,并对该属进行了全面的比较分析。比较结果表明,基因编号,GC含量,密码子偏好模式具有很高的相似性,但SC/IR的边界不同,我们确定了六种不同类型的SC/IR边界。Accronemachienii的SC/IR边界与其他Acronema成员显着不同,这与Tongolia属的VI型模式一致。我们还鉴定了十二个潜在的DNA条形码区(ccsA,matK,ndhF,ndhG,psaI,psbI,rpl32,rps15,ycf1,ycf3,psaI-ycf4和psbM-trnD)用于Acronema中的物种鉴定。Acronema的分子进化相对保守,只有一个基因(petG)处于正选择状态(ω=1.02489)。
■petG基因是光合作用过程中参与光合作用电子链传递的基因之一,在植物的光合作用过程中起着至关重要的作用。这也是高海拔地区植物对环境适应性进化的表现。总之,我们的研究提供了对质体适应性进化的新见解,系统发育,和Acronema属的分类学。
UNASSIGNED: The genus Acronema, belonging to Apiaceae, includes approximately 25 species distributed in the high-altitude Sino-Himalayan region from E Nepal to SW China. This genus is a taxonomically complex genus with often indistinct species boundaries and problematic generic delimitation with Sinocarum and other close genera, largely due to the varied morphological characteristics.
UNASSIGNED: To explore the phylogenetic relationships and clarify the limits of the genus Acronema and its related genera, we reconstructed a reliable phylogenetic framework with high support and resolution based on two molecular datasets (
plastome data and ITS sequences) and performed morphological analyses.
UNASSIGNED: Both phylogenetic analyses robustly supported that Acronema was a non-monophyletic group that fell into two clades: Acronema Clade and East-Asia Clade. We also newly sequenced and assembled sixteen Acronema complete plastomes and performed comprehensively comparative analyses for this genus. The comparative results showed that the
plastome structure, gene number, GC content, codon bias patterns were high similarity, but varied in borders of SC/IR and we identified six different types of SC/IR border. The SC/IR boundaries of Acronema chienii were significantly different from the other Acronema members which was consistent with the type VI pattern in the genus Tongoloa. We also identified twelve potential DNA barcode regions (ccsA, matK, ndhF, ndhG, psaI, psbI, rpl32, rps15, ycf1, ycf3, psaI-ycf4 and psbM-trnD) for species identification in Acronema. The molecular evolution of Acronema was relatively conservative that only one gene (petG) was found to be under positive selection (ω = 1.02489).
UNASSIGNED: The gene petG is one of the genes involved in the transmission of photosynthetic electron chains during photosynthesis, which plays a crucial role in the process of photosynthesis in plants. This is also a manifestation of the adaptive evolution of plants in high-altitude areas to the environment. In conclusion, our study provides novel insights into the
plastome adaptive evolution, phylogeny, and taxonomy of genus Acronema.