Complete Mitogenome Assembly and Comparative Analysis of Vaccinium bracteatum (Ericaceae), a Rich Source of Health-Promoting Molecules

Abstract

Vaccinium bracteatum is a valuable plant used both as food and medicine in China, but low production limits the development of its industry. As such, it is important to develop genetic resources for the high-value species for preservation of wild populations and utilization. The complete chloroplast and nuclear genomes have already been available; however, its mitogenome has not yet been characterized. Here, the V. bracteatum mitogenome was assembled using HiFi reads, and a comparative analysis was conducted. The mitogenome was a circular sequence of 708,384 bp with a GC content of 45.28%, in which 67 genes were annotated, including 36 protein-coding genes, 26 tRNA genes, 3 rRNA genes, and 2 pseudogenes. Overall, 370 dispersed repeats, 161 simple repeats, and 42 tandem repeats were identified, and 360 RNA editing sites were predicted. There was extensive DNA migration among the three genomes. In addition, most of the protein-coding genes underwent purifying selection throughout evolution, and the nucleotide diversity was highly variable. In addition, comparative analysis indicated that the sizes, structures, and gene contents of the mitogenomes differed significantly, but the GC contents and functional genes were relatively conserved among the Ericales species. Mitogenome-based phylogenetic analysis indicated the precise. evolutionary and taxonomic status of V. bracteatum. The complete mitogenome represents the last link of the reference genome of V. bracteatum and lays the foundation for effective utilization and molecular breeding of this plant.