Comparative Plastome Analyses of Ephedra przewalskii and E. monosperma (Ephedraceae)

Abstract

Ephedra species were erect, branching shrubs found in desert or arid regions worldwide as the source of ephedrine alkaloids. In this study, the complete chloroplast genome of Ephedra przewalskii and E. monosperma on the Qinghai-Tibet Plateau were sequenced, assembled, and annotated. Compared with the other four published Ephedra species, the chloroplast genomes of Ephedra species were highly conservative, with a quadripartite structure. The length of the chloroplast genome was 109,569 bp in E. przewalskii with 36.6% GC and 109,604 bp in E. monosperma with 36.6% GC. We detected 118 genes in both Ephedra species, including 73 PCGs, 37 tRNA genes, and eight rRNA genes. Among them, the ndh family genes were lost, which could be used to study the phylogeny and genetic diversity of the genus Ephedra, combined with multiple highly variable intergenic spacer (IGS) regions. Codon usage preference of Ephedra species was weak. The ratio of non-synonymous substitutions and synonymous substitutions was low, showing that the PCGs of Ephedra may be under the pressure of purifying selection. ML and BI analysis showed similar phylogenetic topologies. Ephedra species clustered together in a well-supported monophyletic clade. E. przewalskii and E. monosperma were not gathered in one clade, consistent with the classification system by Flora of China. This study reveals differences in the chloroplast genomes of Ephedra, providing valuable and abundant data for the phylogenetic analysis and species identification of Ephedra.

Phytochemical Screening, Antioxidant Potential, and LC–ESI–MS Profiling of Ephedra alata and Ephedra altissima Seeds Naturally Growing in Tunisia

“…These plants are well known for their high medicinal and ecological importance. Based on their deep and well-developed root system and their tolerance to cold and drought, Ephedra species are widely used in the ecological conservation projects, especially for sand fixation and soil conservation programs [ 2 ]. Ephedra species extracts have recently been proven to be useful in the treatment of COVID-19 [ 3 ].…”