Comparative Analysis of the Complete Mitochondrial Genome Sequence of an Alpine Plant Triosteum pinnatifidum

—In this study, the complete mitochondrial genome (mt genome) of Triosteum pinnatifidum was investigated for the first time. The mt genome was consisted of 803 609 bp, comprised of 62 genes including 19 tRNA genes, 3 rRNA genes and 40 protein-coding genes. We detected protein-coding genes and codon usage, RNA editing sites and repeat sequences. The protein-coding genes substitution rates, DNA segments migration, comparison of six species genomic features were generated. Phylogenetic analysis of 32 species was also taken. A total of 463 RNA editing sites were found in 40 protein-coding genes. Being slightly positive, the GC-skew and AT-skew are 0.0060 and 0.0004, respectively. Most of PCGs have Ka/Ks ratio less than 1, indicating the existence of purifying or negative selection in these genes. This is the first report mt genome in the family Caprifoliaceae and could provide a useful foundation for evolutionary analysis, molecular biology and taxonomy in genus Triosteum and other higher plants.