Assembly and characterization analysis of the complete mitochondrial genome of Lithocarpus litseifolius (Hance) Chun

Lithocarpus litseifolius (Hance) Chun (L. litseifolius 1837) is an evergreen tree of the Fagaceae. It is commonly known as sweet tea and is a natural sweetener with high levels of dihydrochalcone. In addition, L. litseifolius is a precious medicinal material, and its phlorizin has a unique role in the treatment of diabetes. This investigation aimed to assemble and scrutinize the entire mitochondrial (mt) genome of L. litseifolius. The circular mt genome of L. litseifolius spans 573,177 bp and has a GC content of 45.61%. The mt genome of L. litseifolius comprises 61 genes, of which 21 are tRNA genes, 3 are rRNA genes, 36 are protein-coding genes (PCGs), and 1 is a pseudogene. Tetramer repeats made up 32.57% of all identified simple repeat sequences (SSRs), making them the most abundant type of SSR. 35 PCGs with a combined length of 32,208 bp were predicted to include a total of 461 RNA editing sites in the L. litseifolius mt genome. Besides, nine homologous genes between the chloroplast and mt genomes of L. litseifolius were identified. Furthermore, this study demonstrated that while plant mt genome sizes vary considerably, the GC content of these genomes has remained largely constant. The most conservative genes are atp6, rps1, ccmC, rpl2, nad4, nad7, and trnY-GTA. The phylogenetic analysis confirmed that L. litseifolius was genetically more closely related to Quercus variabilis. This study establishes the groundwork for investigations on the systematic evolution, genetic variability, and breeding of L. litseifolius.