Characterization of the complete chloroplast genome of Thalictrum foliolosum DC. 1817, a folk medicine plant in China.

Thalictrum foliolosum DC. 1817, a widely distributed species in the genus of Thalictrum, is used as a traditional herbal medicine in China. For the first time, the complete chloroplast (cp) genome of T. foliolosum was assembled and characterized for the first time in this study. The cp genome of T. foliolosum was 155,764 bp in length, including a large-single copy region of 85,086 bp, a small-single copy region of 17,636 bp, and a pair of inverted repeats region of 53,042 bp. The overall GC content was 38.50%. A total of 127 genes were predicted, including 82 protein-coding genes, 37 tRNA genes, and 8 ribosomal RNA genes. Phylogenetic analysis indicated that T. foliolosum is closely related to T. petaloideum.

Thalictrum foliolosum DC. 1817 is a perennial herbaceous plant that belongs to the Ranunculaceae family (Wang and Sun 2018). Its rhizome is used as a traditional ethnic medicine to treat stomachache, enteritis, dysentery, and tumors(Xu et al., 1990; Zou et al. 1999). Previous studies have focused on pharmacological activity, chemical composition, morphological taxonomy, and molecular phylogeny of T. foliolosum (Chen et al. 2003; Khamidullina et al. 2006; Hao et al. 2015; Bai 2019; Gregory and Prakash 2020). However, no studies have provided a complete chloroplast (cp) genomic report on T. foliolosum to date. Herein, we assembled and characterized the cp genome of T. foliolosum for the first time, which will provide helpful information for further study of the genus.

This article is licensed under a Regulations of Yunnan Province on biodiversity protection and approved by Yangbi counties (Yunnan Province, China), Dali University (Yunnan province of China). Fresh leaves of T. foliolosum were collected from the Dapingdi mountain (N 25°40′11.71″, E 99°57′29.30″) in Yangbi counties, Yunnan province, China. The specimens were deposited at the herbarium of Dali University (http://yxy.dali.edu.cn/yhxy, Baozhong Duan, bzduan@126.com) under the voucher number HD2021040513. Total DNA was extracted using the DNeasy plant mini kit (QIAGEN) and sequenced by the Illumina NovaSeq system (Illumina, San Diego, CA). Approximately 5.51 Gb of raw data were assembled by NOVOPlasty (Dierckxsens et al. 2017), and annotated by GeSeq with default sets (Tillich et al. 2017). The GenBank accession number is MZ196217.

The cp genome of T. foliolosum was 155,764 bp in length with a typical quadripartite structure of angiosperms, which contained a large single-copy region of 85,086 bp, a small single-copy region of 17,636 bp, and a pair of inverted repeats region of 53,042 bp. A total of 127 genes were identified, including 82 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content was 38.50%. Phylogenetic analysis was performed on 22 cp genomes, and two taxa were used as an outgroup to reveal the phylogenetic relation. The sequences were aligned by MAFFT v7.307 (Nakamura et al. 2018). A Maximum-Likelihood tree (1000 bootstrap replicates) was accessed using IQ-tree (Jiang et al. 2020), with Berberis ganpinensis (MN417307) and Berberis weiningensis (NC_056989) as outgroup. Phylogenetic analysis showed that T. foliolosum was closely related to T. petaloideum (Figure 1). The cp genome of T. foliolosum will provide a valuable resource for the conservation genetics of this species and the phylogenetic studies of Thalictrum.

Figure 1.

Maximum-likelihood phylogenetic tree based on the complete chloroplast genome sequences of 20 plant species from Ranunculaceae and 2 outgroups plant species from Berberis.

Author contributions

Tingting Pu analyzed the data, prepared figures, wrote original draft, and approved the final draft; Zhongyu Zhou collected materials and analyzed the data; Zhonglian Zhang performed the experiments and interpretation of data for the work; Manchang Zhang designed the experiments, reviewed and edited the draft.