Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen 518004, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.
Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen 518004, China.
Mol Phylogenet Evol. 2021 Aug;161:107171. doi: 10.1016/j.ympev.2021.107171. Epub 2021 Mar 30.
With some 7300 species of small nonvascular spore-producing plants, liverworts represent one of the major lineages of land plants. Although multi-locus molecular phylogenetic studies have elucidated relationships of liverworts at different taxonomic categories, the backbone phylogeny of liverworts is still to be fully resolved, especially for the placement of Ptilidiales and the relationships within Jungermanniales and Marchantiales. Here, we provided phylogenomic inferences of liverworts based on 42 newly sequenced and 24 published liverwort plastid genomes representing all but two orders of liverworts, and characterized the evolution of the plastome in liverworts. The structure of the plastid genome is overall conserved across the phylogeny of liverworts, with only two structural variants detected from simple thalloids, besides 18 out of 43 liverwort genera showing intron variations in their plastomes. Complex thalloid liverworts maintain the most plastid genes, and seem to undergo fewer gene deletions and pseudogenization events than other liverworts. Plastid phylogenetic inferences yielded mostly robustly supported relationships, and consistently resolved Ptilidiales as the sister to Porellales. The relative ratio of silent substitutions across the three genetic compartments (i.e., 1:15:10, for mitochondrial:plastid:nuclear) suggests that liverwort plastid genes have the potential to evolve faster than their nuclear counterparts, unlike in any other major land plant lineages where the mutation rate of nuclear genes overwhelm those of their plastid and mitochondrial counterparts.
拥有约 7300 种小型非维管束孢子植物，地钱代表了陆地植物的主要谱系之一。尽管多基因座分子系统发育研究阐明了不同分类群地钱的关系，但地钱的系统发育主干仍然有待完全解决，特别是对于叶苔目和地钱目内的关系。在这里，我们提供了基于 42 个新测序和 24 个已发表的地钱质体基因组的地钱系统发育基因组学推断，这些基因组代表了除两个地钱目之外的所有地钱目，并且还对地钱质体的进化进行了特征描述。除了在 43 个地钱属中的 18 个属中在其质体基因组中显示出内含子变异外，质体基因组的结构在整个地钱系统发育中总体上是保守的，仅从简单的叶状体中检测到两个结构变体。复杂的叶状地钱保留了最多的质体基因，并且似乎比其他地钱经历的基因缺失和假基因化事件更少。质体系统发育推断产生了大多数稳健支持的关系，并且一致地将叶苔目解析为叶苔目的姐妹目。三个遗传区室（即线粒体：质体：核）之间的沉默替换的相对比例（即 1:15:10）表明，与任何其他主要陆地植物谱系不同，地钱质体基因具有比其核对应物更快进化的潜力，在这些陆地植物谱系中，核基因的突变率超过了其质体和线粒体对应物。
