Complete mitogenome and phylogenetic analysis of the tertiary relict shrub <i>Platycrater arguta</i> (Hydrangeaceae)

Platycrater arguta Siebold & Zucc., is a monotypic Hydrangeaceae genus, yet its mitogenomic information remains limited. We assembled its mitogenome from PacBio HiFi reads: 435,757 bp (45.76% GC), containing 66 genes (36 protein-coding, 27 tRNA, 3 rRNA). Complex trans-splicing introns occurred in nad1, nad2 and nad5; codons were strongly AT-biased. It also had 100 large dispersed repeats (>50 bp), 26 tandem repeats and 136 SSRs. Using shared PCGs from 21 species, P. arguta fell within Hydrangeaceae, sister to Hydrangea macrophylla and H. chinensis (100% bootstrap). This mitogenome is a valuable resource for Hydrangeaceae phylogeny and comparative genomics.