The complete chloroplast genome of Mesosphaerum suaveolens (L.) Kuntze and phylogenetic position in the Lamiaceae family

Abstract

The complete chloroplast genome of Mesosphaerum suaveolens is 152,555 base pairs long and has a typical quadripartite structure. It contains 132 genes, including 13 cis-splicing genes, 2 trans-splicing genes (rps12), and 8 tRNA genes with introns. A total of 47 simple sequence repeats (SSRs) were identified: 41 mononucleotide repeats (19 A, 1 C, 21 T), 4 dinucleotide repeats (2 TA, 2 AT), and 2 complex repeats (21 bp and 81 bp). The genes rps19 (LSC and IRb), ndhF (SSC and IRb), and ycf1 (SSC and IRa) are located at the borders between two regions. The most frequently used codons and amino acids are UGU (Cys), GGU (Gly), UUA (Leu), and UUU (Phe). Phylogenetic analysis indicates that the chloroplast genome of M. suaveolens is closely related to Ocimum gratissimum, and that the Isodon Hanceola clade forms a major clade comprising 19 species across 11 Lamiaceae genera. These findings support species identification, evolutionary research, and conservation genetics for M. suaveolens and related medicinal plants.