Abstract
We assembled and characterized the complete chloroplast genome sequence of Myxopyrum hainanense to investigate its phylogenetic position. The plastome is 156,064 bp in length, which is comprised of a large single-copy (LSC) region of 86,851 bp, a small single-copy (SSC) region of 17,837 bp, and two inverted repeat (IR) regions of 25,688 bp. The overall GC content of the plastome was 37.7. The new sequence comprised total 135 genes, including 87 protein-coding genes, 8 ribosomal RNA genes, and 40 tRNA genes. Phylogenetic analysis showed that M. hainanense was close to Nyctanthes arbor-tristis.
The Oleaceae is a family of flowering plants in the order Lamiales, which consists of about 700 species in 25 extant genera (Green Citation2004). Many species are economically important, such as the olive (Olea europaea), the ash tree (Fraxinus excelsior) and numerous ornamentals or fragrant species (i.e., the genera Forsythia, Ligustrum, Jasminum, Osmanthus, and Syringa). Here, we report the first complete plastome of Myxopyrum hainanense, an endemic shrub in Hainan, China and we constructed a phylogenetic tree including 23 of the 25 extant genera to investigate its position (GenBank accession number: MN908148).
The leaves of M. hainanense were sampled from South China Botanical Garden, Guangzhou, China (23.1928°N,113.3706°E) and the voucher specimen was deposited at the Herbarium of Guizhou Normal University (Accession number: Zhu201905005). We extracted total genomic DNA with the Qiagen DNeasy Plant Mini Kit (Qiagen, Carlsbad, CA, USA), and performed the subsequent high-throughput sequencing on an Illumina Hiseq 2500 System. We assembled the plastome using GetOrganelle v1.6.2e (Jin et al. Citation2018). Annotation was performed using PGA (Qu et al. Citation2019) and manually corrected.
The plastome is 156,064 bp in length, which is comprised of a large single-copy (LSC) region of 86,851 bp, a small single-copy (SSC) region of 17,837 bp, and two inverted repeat (IR) regions of 25,688 bp. The new sequence comprised total 135 genes, including 87 protein-coding genes, 8 ribosomal RNA genes, and 40 tRNA genes. In these genes, ten protein-coding genes (atpF, ndhA, ndhB, petB, petD, rpl16, rpl2, rps12, rpoC1, rps16) contained one intron and two genes (clpP and ycf3) contained two introns. The overall percentage of GC content was 37.7, and the corresponding value of the LSC, SSC, and IR region were 35.2, 31.5, and 43.2, respectively.
To further investigate the phylogenetic position of M. hainanense, a maximum likelihood tree was constructed based on 22 published complete plastomes of Oleaceae and the new plastome. The published chloroplast genome sequences of Silvianthus bracteatus (Carlemanniaceae) was defined as outgroup, because the Carlemanniaceae family was a sister group to the Oleaceae (Stevens Citation2017; Zhu et al. Citation2020). We using RAxML (Stamatakis Citation2014) to construct the tree after the sequences were aligned using MAFFT v7.307 (Katoh and Standley Citation2013). Our results showed that M. hainanense was close to Nyctanthes arbor-tristis (). This published M. hainanense chloroplast genome will provide useful information for phylogenetic and evolutionary studies in Oleaceae.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability
The data that support the findings of this study are openly available in GenBank (https://www.ncbi.nlm.nih.gov/) with accession number MN908148.
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Funding
References
- Green PS. 2004. Oleaceae. In K. Kubitzki & J. W. Kadereit, editors. The families and genera of vascular plants. Flowering plants, dicotyledons. Vol. VII. New York, NY: Springer; p. 296–306.
- Jin J-J, Yu W-B, Yang J-B, Song Y, Yi T-S, Li D-Z. 2018. GetOrganelle: a fast and versatile toolkit for accurate de novo assembly of organelle genomes. BioRxiv. 256479.
- Katoh K, Standley DM. 2013. MAFFT multiple sequence alignment soft-ware version 7: improvements in performance and usability. Mol Biol Evol. 30(4):772–780.
- Qu X-J, Moore MJ, Li D-Z, Yi T-S. 2019. PGA: a software package for rapid, accurate, and flexible batch annotation of plastomes. Plant Methods. 15(1):1–12.
- Stamatakis A. 2014. RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics. 30(9):1312–1313.
- Stevens PF. 2017. Angiosperm phylogeny website. Version 14. [accessed 2012 Jan 1]. http://www.mobot.org/MOBOT/Research/APweb/.
- Zhu X, Yang K, Xiong Z, Li X. 2020. The complete chloroplast genome of Silvianthus bracteatus (Carlemanniaceae) and phylogenic analysis of Lamiales. Mitochondrial DNA Part B. 5(2):1132–1133.