Extensive gene loss in the plastome of holoparasitic plant Cistanche tubulosa (Orobanchaceae)

Abstract

Extensive photosynthetic gene loss and rapid evolutionary rate occur in the plastomes of parasitic plants. The holoparasitic plant Cistanche tubulosa of Orobanchaceae is an important medicinal resources that are distributed in arid areas. In this study, the complete plastome of C. tubulosa has been sequenced, assembled and analyzed. The total plastome of C. tubulosa was 75,375 bp in length, consisting of a pair of inverted repeats (IRs, 6,593 bp), a large single-copy region (LSC, 32,470 bp) and a small single-copy region (SSC, 29,719 bp). It contained 24 intact protein coding genes, nine pseudogenes, and 44 missing genes. In addition, all the protein-coding genes, which were related to photosynthesis and energy production, were pseudogenised or lost. Four rRNA genes and 24 tRNA genes were intact meanwhile five tRNA genes were missing. Phylogenetic tree indicated that C. tubulosa was closely related to C. phelypaea. Our results may improve understanding of the plastome organization, classification, and evolution of parasitic plants.

Keywords:

• Cistanche tubulosa
• plastome
• gene loss
• holoparasitic plant
• phylogenetic analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are deposited in GenBank, with accession numbers of MN614130. https://www.ncbi.nlm.nih.gov/nuccore/MN614130.1/.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [81473315, U1812403-1-1], National Science & Technology Fundamental Resources Investigation Program of China [2018FY100701] and CAMS Innovation Fund for Medical Sciences [2016-I2M-3-015], which are gratefully acknowledged.