PDF(Pubmed)
Abstract：
Tortula atrovirens (Sm.) Lindb. is an important component of biological soil crusts and possesses an extraordinary tolerance against desiccation in dryland habitats. However, knowledge of the organelle genome of this desiccation-tolerant (DT) moss is still lacking. Here, we assembled the first reported Tortula organelle genome and conducted a comprehensive analysis within the Pottiaceae family. T. atrovirens exhibited the second largest chloroplast genome (129,646 bp) within the Pottiaceae, whereas its mitogenome (105,877 bp) and those of other mosses were smaller in size compared to other land plants. The chloroplast and mitochondrial genomes of T. atrovirens were characterized by the expansion of IR boundaries and the absence of homologous recombination-mediated by large repeats. A total of 57 RNA editing sites were detected through mapping RNA-seq data. Moreover, the gene content and order were highly conserved among the Pottiaceae organelle genomes. Phylogenetic analysis showed that bryophytes are paraphyletic, with their three lineages (hornworts, mosses, and liverworts) and vascular plants forming successive sister clades. Timmiella anomala is clearly separated from the monophyletic Pottiaceae, and T. atrovirens is closely related to Syntrichia filaris within the Pottioideae. In addition, we detected four hypervariable regions for candidate-molecular markers. Our findings provide valuable insights into the organelle genomes of T. atrovirens and the evolutionary relationships within the Pottiaceae family, facilitating future discovery of DT genetic resources from bryophytes.
摘要：
托尔图拉·阿特维伦斯（Sm。)林德。是生物土壤结皮的重要组成部分，对旱地栖息地的干燥具有非凡的耐受性。然而,仍然缺乏这种耐干燥（DT）苔藓的细胞器基因组的知识。这里,我们组装了第一个报告的Tortula细胞器基因组，并在Pottiaceae家族中进行了全面分析。T.atrovirens在Pottiaceae中表现出第二大叶绿体基因组（129,646bp），与其他陆地植物相比，其有丝分裂基因组（105,877bp）和其他苔藓的大小较小。T.atrovirens的叶绿体和线粒体基因组的特征在于IR边界的扩展和不存在大重复序列介导的同源重组。通过作图RNA-seq数据检测到总共57个RNA编辑位点。此外，该基因的含量和顺序在Pottiaceae细胞器基因组中高度保守。系统发育分析表明苔藓植物是共生的，他们的三个血统(角，苔藓,和苔藓）和维管植物形成连续的姐妹进化枝。Timmiellaanomala显然与单系pottiaceae分开，和T.atrovirens与Pottioideae内的丝状体紧密相关。此外,我们检测到四个候选分子标记的高变区。我们的发现为T.atrovirens的细胞器基因组和Pottiaceae家族中的进化关系提供了有价值的见解，促进未来从苔藓植物中发现DT遗传资源。
