The complete chloroplast genome sequence of Nepeta bracteata and comparison with congeneric species

Nepeta bracteata (N. bracteata) is an important medicinal plant used by Chinese ethnic minorities. However, the lack of knowledge regarding the chloroplast genome of N. bracteata has imposed current limitations on our study. Here, we used Next-generation sequencing to obtain the chloroplast genome of N. bracteata. The findings suggested that the 151,588 bp cp genome of N. bracteata comprises 130 genes, including 35 tRNA genes and 87 protein-coding genes. And its chloroplast genome exhibits a typical quadripartite structure, the largest single copy (LSC; 82,819 bp) and the smallest single copy (SSC; 17,557 bp) separate a pair of inverted repeats IR regions (IRa and IRb; 25,606 bp) from one another. Interestingly, palindromic repeats are more common, as shown by the examination of repetition. In the interim, 18 SSRs were discovered in the interim, the bulk of which were Adenine-Thymine (A-T) mononucleotides. Meanwhile, we compared it with five other species from the Nepeta genus. Five hypervariable areas were found by the study, including ndhH-rps15, accD-psal, ndhG-ndhl, trnH-GUGpsbA, and rpoC1-rpoB. Furthermore, the phylogenetic study revealed that N. bracteata and Nepeta stewartiana (N. stewartiana) were linked to each other most closely. In summary, our findings enrich the resources available for chloroplast genomes in the Nepeta genus. Moreover, these hypervariable regions have the potential to be developed into molecular markers, enabling the rapid identification of species within the Nepeta genus. Comparative analysis of species within the Nepeta genus can help enhance our study of their phylogenetic relationships, potential medicinal properties and bioprospecting.

Automated summary

This study successfully obtained the chloroplast genome of Nepeta bracteata using Next-generation sequencing. The genome consists of 130 genes and exhibits a typical quadripartite structure. Comparative analysis with other species from the Nepeta genus identified five hypervariable regions. Phylogenetic analysis showed a close relationship between N. bracteata and Nepeta stewartiana. These findings enrich the resources available for chloroplast genomes in the Nepeta genus and highlight the potential of hypervariable regions as molecular markers.