Sequence Analysis of the Complete Mitochondrial Genome of a Medicinal Plant, Vitex rotundifolia Linnaeus f. (Lamiales: Lamiaceae)

In the present study, we depicted the complete mitochondrial genome of a valuable medicinal plant, Vitex rotundifolia. The mitochondrial genome of V. rotundifolia, mapped as a circular molecule, spanned 380,980 bp in length and had a GC content of 45.54%. The complete genome contained 38 protein-coding genes, 19 transfer RNAs (tRNAs), and 3 ribosomal RNAs (rRNAs). We found that there were only 38.73% (147.54 kb), 36.28% (138.23 kb), and 52.22% (198.96 kb) of the homologous sequences in the mitochondrial genome of V. rotundifolia, as compared with the mitochondrial genomes of Scutellaria tsinyunensis, Boea hygrometrica, and Erythranthe lutea, respectively. A multipartite structure mediated by the homologous recombinations of the three direct repeats was found in the V. rotundifolia mitochondrial genome. The phylogenetic tree was built based on 10 species of Lamiales, using the maximum likelihood method. Moreover, this phylogenetic analysis is the first to present the evolutionary relationship of V. rotundifolia with the other species in Lamiales, based on the complete mitochondrial genome.