Project description:IntroductionPhylogenomics have been widely used to resolve ambiguous and controversial evolutionary relationships among plant species and genera, and the identification of unique indels in plastomes may even help to understand the evolution of some plant families. Menispermum L. (Menispermaceae) consists of three species, M. dauricum DC., M. canadense L., and M. mexicanum Rose, which are disjuncly distributed among East Asia, Eastern North America and Mexico. Taxonomists continue to debate whether M. mexicanum is a distinct species, a variety of M. dauricum, or simply a synonym of M. canadense. To date, no molecular systematics studies have included this doubtful species in phylogenetic analyses.MethodsIn this study, we examined phylogenomics and phylogeography of Menispermum across its entire range using 29 whole plastomes of Menispermaceae and 18 ITS1&ITS2 sequences of Menispermeae. We reconstructed interspecific relationships of Menispermum and explored plastome evolution in Menispermaceae, revealing several genomic hotspot regions for the family.Results and discussionPhylogenetic and network analyses based on whole plastome and ITS1&ITS2 sequences show that Menispermum clusters into two clades with high support values, Clade A (M. dauricum) and Clade B (M. canadense + M. mexicanum). However, M. mexicanum is nested within M. canadense and, as a result, we support that M. mexicanum is a synonym of M. canadense. We also identified important molecular variations in the plastomes of Menispermaceae. Several indels and consequently premature terminations of genes occur in Menispermaceae. A total of 54 regions were identified as the most highly variable plastome regions, with nucleotide diversity (Pi) values > 0.05, including two coding genes (matK, ycf1), four introns (trnK intron, rpl16 intron, rps16 intron, ndhA intron), and 48 intergenic spacer (IGS) regions. Of these, four informative hotspot regions (trnH-psbA, ndhF-rpl32, trnK-rps16, and trnP-psaJ) should be especially useful for future studies of phylogeny, phylogeography and conservation genetics of Menispermaceae.
Project description:Menispermum dauricum is a woody liana with great medicinal value. In the current study, we assembled the first chloroplast (cp) genome of M. dauricum. The whole chloroplast genome is 158,623 bp in length, with one large copy region (LSC: 88,879 bp), a small single copy region (SSC: 20,644 bp), and two inverted repeats (IR: 24,550 bp). The cp genome contains 114 unique genes with 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. In our phylogeny of Ranunculales, Papaveraceae is found to be the basal group of Ranunculales and M. dauricum is sister to Stephania japonica.
Project description:The purpose of this study was to investigate the structural characterization and immunological activity in vitro and in vivo of a polysaccharide from the rhizome of Menispermum dauricum. A new polysaccharide named MDP was isolated from the rhizome of Menispermum dauricum by hot water extraction, ethanol precipitation, anion-exchange, and gel-filtration chromatography. MDP was homogeneous and had a molecular weight of 6.16 ×103 Da, and it was an α-D-glucan containing a (1 → 6)-linked backbone, with a glucosyl residue at the C-3 position along the main chain. MDP exhibited immunological activity in vitro, which could significantly promote the proliferation and phagocytosis of RAW264.7 cells and the release of TNF-α and IL-6 factors. For immunological activity in vivo. MDP could significantly increase the thymus and spleen indices, enhance the macrophage function, increase the level of cytokine (IL-6 and TNF-α) and immunoglobulin IgM in the serum and regulate T lymphocyte subsets. Furthermore, MDP elevated the expression of the critical nodes in the TLR4-MyD88 signaling pathways in vivo. These results support the concept that MDP may exhibit immunological activity through TLR4-MyD88 signaling pathway in vivo.
| S-EPMC9240474 | biostudies-literature
Project description:Transcriptome sequencing of Rhododendron dauricum in 2019
Project description:The moonseed genus Menispermum L. (Menispermaceae) is disjunctly distributed in East Asia and eastern North America. Although Menispermum has important medicinal value, genetic and genomic information is scarce, with very few available molecular markers. In the current study, we used Illumina transcriptome sequencing and de novo assembly of the two Menispermum species to obtain in-depth genetic knowledge. From de novo assembly, 53,712 and 78,921 unigenes were generated for M. canadense and M. dauricum, with 37,527 (69.87%) and 55,211 (69.96%) showing significant similarities against the six functional databases, respectively. Moreover, 521 polymorphic EST-SSRs were identified. Of them, 23 polymorphic EST-SSR markers were selected to investigate the population genetic diversity within the genus. The newly developed EST-SSR markers also revealed high transferability among the three examined Menispermaceae species. Overall, we provide the very first transcriptomic analyses of this important medicinal genus. In addition, the novel microsatellite markers developed here will aid future studies on the population genetics and phylogeographic patterns of Menispermum at the intercontinental geographical scale.