Comparative Analysis of Chloroplast Genome Between Widely Distributed and Locally Distributed Lysionotus...

The genus Lysionotus belongs to the family Gesneriaceae and includes plants with both ornamental and medicinal value. However, genomic-level data on the genus remains scarce. Previous investigations of Lysionotus have predominantly centered on morphological classification, with only limited exploration of molecular phylogenetics. Comparative analysis of chloroplast genomes within the genus would provide valuable insights into the genetic variations and evolutionary patterns of Lysionotus plants. In this study, we present the analysis of 24 newly sequenced chloroplast genomes from Lysionotus-related members, including widely distributed and locally distributed species. The results showed that the 11 plastome sizes of widely distributed species ranged from 152,928 to 153,987 bp, with GC content of 37.43-37.49%; the 13 plastome sizes of locally distributed species ranged from 153,436 to 153,916 bp, with GC content of 37.43-37.48%. A total of 24 chloroplast genomes owned typical quadripartite structures, and the number of tRNA (36 tRNAs) and rRNA (4 rRNAs) were observed for all 24 genomes. However, the number of their protein-coding sequences (CDs) varied at individual levels. No contraction and expansion of IR borders, gene rearrangements, or inversions were detected. mVISTA and Pi showed inverted repeats (IR) region was more conserved than the single copy region, coding region was more conserved than the non-coding region. Additionally, the repeat sequences and codon usage bias of Lysionotus plastomes were also conserved. Our results offer a comprehensive understanding of the genetic differences among these species and shed light on their phylogenetic systematics.