Mitochondrial genome of Lonicera macranthoides: features, RNA editing, and insights into male sterility

The complete mitogenome of <i>L. macranthoides</i> 'Yulei 1' was obtained for the first time, with a length of 1,002,202 bp. It contains 48 protein-coding genes (PCGs), 26 tRNA genes, and 3 rRNA genes. Additionally, 79 simple sequence repeats (SSRs), 39 tandem repeats, and 99 dispersed repeats were identified. Among these, two direct repeats (RP1a/1b, RP2a/2b) and two inverse repeats (RP3a/b, RP4a/b) may facilitate mitogenome recombination. Gene transfer analysis revealed that 4.36% and 21.98% of mitogenomic sequences mapped to the chloroplast and nuclear genomes, respectively. Phylogenetic analysis indicated that <i>L. macranthoides</i> is closest to <i>L. japonica</i> at the mitogenome level. Notably, RNA editing events varied across different plant tissues, with 357 editing sites in 30 PCGs in leaves, 138 sites in 24 PCGs in flowers, and 68 sites in 13 PCGs in stems. Finally, all indications of CMS in the mitogenome were screened, including the detection of ORFs, and the findings showed no mutations in the mitogenome that would explain the sterility of 'Yulei 1'. Overall, our study provides a complete mitogenome of <i>L. macranthoides</i>, which will aid in its genetic marker exploration, evolutionary relationship analysis, and breeding programs.