The Complete Chloroplast and Mitochondrial Genome Sequences of <em>Boea hygrometrica</em>: Insights into the Evolution of Plant Organellar Genomes

<div><p>The complete nucleotide sequences of the chloroplast (cp) and mitochondrial (mt) genomes of resurrection plant <em>Boea hygrometrica</em> (<em>Bh</em>, 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 <em>Bh</em> cp genome has a typical quadripartite organization with a conserved gene in each region. The <em>Bh</em> 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 <em>Bh</em> mt genome is the frequent transfer of genetic material from the cp genome during recent <em>Bh</em> 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.</p>