Complete Chloroplast Genome Characterization, and Phylogenetic Analyses of the Rare and Endangered Plant Platycrater arguta

As an important rare and endangered plant, Platycrater arguta urgently requires protective measures. In this study, we assembled and annotated a more complete chloroplast genome of P. arguta, which has a size of 157,812 bp. The chloroplast genome comprises a large single-copy (LSC) region of 86,825 bp, a small single-copy (SSC) region of 18,735 bp, and a pair of inverted repeats (IRa and IRb) of 26,126 bp each. SSR detection revealed that the chloroplast genome contains 199 simple repeat loci, with mononucleotide repeats of A and T being the most frequent, accounting for 59.8%. Comparative analysis of the chloroplast genome structure showed that the IR region boundaries are relatively conserved. The results of the phylogenetic tree indicate that P. arguta shares high homology with Hydrangea davidii. This work provides a scientific basis for future research on the genetics, biology, and conservation of P. arguta.