Ji-Eun Park1P, Yoo-Jung Park1, Halam Kang1, Hyeyeon Kim1, Jae-Eun Choi1, Hyeok Jae Choi2 and Kyeong-Sik Cheon1C

1Department of Biological Science, Sangji University, Wonju, Republic of Korea; 2Department of Biology and Chemistry, Changwon National University, Changwon, Republic of Korea

The genus Orostachys is primarily distributed in East Asia and is utilized as an ornamental and medicinal plant. Some species have been identified as important plant resources due to their therapeutic effects, including immunomodulation and antioxidant activities. The genus Orostachys is divided into two subsections, Appendiculatae and Orostachys, based on the presence or absence of leaf tip appendages. O. thyrsiflora, belonging to subsection Appendiculatae, is restricted to certain regions of Russia, including Orenburg and Kurgan, making it of high conservation value. However, no molecular biological studies at the chloroplast genome level have been conducted on this species. Therefore, this study aimed to decode the chloroplast genome of O. thyrsiflora for the first time and compare it with closely related taxa. The results revealed that the chloroplast genome of O. thyrsiflora was 151,137 bp in length with a G+C content of 37.8%. The cp genome consists of a large single-copy (LSC) region of 82,861 bp, a small single-copy (SSC) region of 16,798 bp, and two inverted repeat (IR) regions of 25,739 bp each. A total of 113 unique genes, including 79 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes, were identified, consistent with other Orostachys taxa. Phylogenetic analyses revealed that O. thyrsiflora exhibited the closest phylogenetic relationship M. sikokianus and clustered and formed a sister group to other taxa in subsection Appendiculatae (O. fimbriata, O. latielliptica, O. japonica, O. japonica f. polycephala, O. margaritifola, O. minuta). This study reports the complete chloroplast genome of O. thyrsiflora for the first time and evaluates its phylogenetic relationships with closely related taxa, providing foundational data for various research fields.