Comparative analyses of eight complete plastid genomes of two hemiparasitic Cassytha vines in the family Lauraceae

Qun-Fei Yu; Yun-Hong Tan; Wen-Bin Yu; Shi-Ting Yang; Jie-Peng Huang; Marcos A Caraballo-Ortiz; Chao Liu; Yu Song

doi:10.3389/fgene.2023.1192170

Comparative analyses of eight complete plastid genomes of two hemiparasitic Cassytha vines in the family Lauraceae

Front Genet. 2023 Dec 13:14:1192170. doi: 10.3389/fgene.2023.1192170. eCollection 2023.

Authors

Qun-Fei Yu^{1

2}, Yun-Hong Tan^{1

3}, Wen-Bin Yu^{1

3}, Shi-Ting Yang⁴, Jie-Peng Huang⁴, Marcos A Caraballo-Ortiz⁵, Chao Liu⁶, Yu Song⁴

Affiliations

¹ Center for Integrative Conservation and Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China.
² University of Chinese Academy of Sciences, Beijing, China.
³ Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw, Myanmar.
⁴ Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Ministry of Education) and Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin, Guangxi, China.
⁵ Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States.
⁶ College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, China.

Abstract

Cassytha is the sole genus of hemiparasitic vines (ca. 20 spp.) belonging to the Cassytheae tribe of the Lauraceae family. It is extensively distributed in tropical and subtropical regions. In this study, we determined the complete plastid genome sequences of C. filiformis and C. larsenii, which do not possess the typical quadripartite structure. The length of C. filiformis plastomes ranged from 114,215 to 114,618 bp, whereas that of C. larsenii plastomes ranged from 114,900 to 114,988 bp. Comparative genomic analysis revealed 1,013 mutation sites, four large intragenomic deletions, and five highly variable regions in the eight plastome sequences. Phylogenetic analyses based on 61 complete plastomes of Laurales species, 19 ITS sequences, and trnK barcodes from 91 individuals of Cassytha spp. confirmed a non-basal group comprising individuals of C. filiformis, C. larsenii, and C. pubescens in the family Lauraceae and proposed a sister relationship between C. filiformis and C. larsenii. Further morphological comparisons indicated that the presence or absence of hairs on the haustoria and the shape or size of fruits were useful traits for differentiating C. filiformis and C. larsenii.

Keywords: Cassytha; Eusideroxylon; Laurales; chloroplast; hemiparasitic genus.

Grants and funding

This work was supported by the National Natural Science Foundation of China (Nos. 32260060 and 32060710) and the Special Program for Technology Bases and Talents of Guangxi (Grant No. 2022AC20002), and the Local Colleges Applied Basic Research Projects of Yunnan Province (Grant No. 202001BA070001-131).