James D. Watson Institute of Genome Sciences, Zhejiang University, Hangzhou, China.
PLoS One. 2012;7(1):e30531. doi: 10.1371/journal.pone.0030531. Epub 2012 Jan 23.
The complete nucleotide sequences of the chloroplast (cp) and mitochondrial (mt) genomes of resurrection plant Boea hygrometrica (Bh, Gesneriaceae) have been determined with the lengths of 153,493 bp and 510,519 bp, respectively. The smaller chloroplast genome contains more genes (147) with a 72% coding sequence, and the larger mitochondrial genome have less genes (65) with a coding faction of 12%. Similar to other seed plants, the Bh cp genome has a typical quadripartite organization with a conserved gene in each region. The Bh mt genome has three recombinant sequence repeats of 222 bp, 843 bp, and 1474 bp in length, which divide the genome into a single master circle (MC) and four isomeric molecules. Compared to other angiosperms, one remarkable feature of the Bh mt genome is the frequent transfer of genetic material from the cp genome during recent Bh evolution. We also analyzed organellar genome evolution in general regarding genome features as well as compositional dynamics of sequence and gene structure/organization, providing clues for the understanding of the evolution of organellar genomes in plants. The cp-derived sequences including tRNAs found in angiosperm mt genomes support the conclusion that frequent gene transfer events may have begun early in the land plant lineage.
已确定复苏植物 Boea hygrometrica（Bh，苦苣苔科）的叶绿体（cp）和线粒体（mt）基因组的完整核苷酸序列，长度分别为 153493bp 和 510519bp。较小的叶绿体基因组包含更多的基因（147 个），其编码序列占 72％，而较大的线粒体基因组包含较少的基因（65 个），其编码序列占 12％。与其他种子植物一样，Bh cp 基因组具有典型的四部分结构，每个区域都有一个保守基因。Bh mt 基因组具有三个重组序列重复，长度分别为 222bp、843bp 和 1474bp，将基因组分为一个主环（MC）和四个等异位点分子。与其他被子植物相比，Bh mt 基因组的一个显著特征是在 Bh 进化过程中，叶绿体基因组的遗传物质频繁转移。我们还分析了细胞器基因组的进化，包括基因组特征以及序列和基因结构/组织的组成动态，为理解植物细胞器基因组的进化提供了线索。在被子植物 mt 基因组中发现的来源于 cp 的序列包括 tRNA，支持了频繁的基因转移事件可能在陆地植物谱系早期就开始的结论。
