Genome structure and diversity among Cynanchum wilfordii accessions

Background Cynanchum wilfordii (Cw) and Cynanchum auriculatum (Ca) have long been used in traditional medicine and as functional food in Korea and China, respectively. They have diverse medicinal functions, and many studies have been conducted, including pharmaceutical efficiency and metabolites. Especially, Cw is regarded as the most famous medicinal herb in Korea due to its menopausal symptoms relieving effect. Despite the high demand for Cw in the market, both species are cultivated using wild resources with rare genomic information. Results We collected 160 Cw germplasm from local areas of Korea and analyzed their morphological diversity. Five Cw and one Ca of them, which were morphologically diverse, were sequenced, and nuclear ribosomal DNA (nrDNA) and complete plastid genome (plastome) sequences were assembled and annotated. We investigated the genomic characteristics of Cw as well as the genetic diversity of plastomes and nrDNA of Cw and Ca. The Cw haploid nuclear genome was approximately 178 Mbp. Karyotyping revealed the juxtaposition of 45S and 5S nrDNA on one of 11 chromosomes. Plastome sequences revealed 1226 interspecies polymorphisms and 11 Cw intraspecies polymorphisms. The 160 Cw accessions were grouped into 21 haplotypes based on seven plastome markers and into 108 haplotypes based on seven nuclear markers. Nuclear genotypes did not coincide with plastome haplotypes that reflect the frequent natural outcrossing events. Conclusions Cw germplasm had a huge morphological diversity, and their wide range of genetic diversity was revealed through the investigation with 14 molecular markers. The morphological and genomic diversity, chromosome structure, and genome size provide fundamental genomic information for breeding of undomesticated Cw plants.

Cynanchum auriculatum Royle ex Wight., Cynanchum bungei Decne. and Cynanchum wilfordii (Maxim.) Hemsl.: Current Research and Prospects

Cynanchum auriculatum Royle ex Wight. (CA), Cynanchum bungei Decne. (CB) and Cynanchum wilfordii (Maxim.) Hemsl. (CW) are three close species belonging to the Asclepiadaceous family, and their dry roots as the bioactive part have been revealed to exhibit anti-tumor, neuroprotection, organ protection, reducing liver lipid and blood lipid, immunomodulatory, anti-inflammatory, and other activities. Until 2021, phytochemistry investigations have uncovered 232 compounds isolated from three species, which could be classified into C21-steroids, acetophenones, terpenoids, and alkaloids. In this review, the morphology characteristics, species identification, and the relationship of botany, extraction, and the separation of chemical constituents, along with the molecular mechanism and pharmacokinetics of bioactive constituents of three species, are summarized for the first time, and their phytochemistry, pharmacology, and clinical safety are also updated. Moreover, the direction and limitation of current research on three species is also discussed.

Nocardioides cynanchi sp. nov., isolated from soil of rhizosphere of Cynanchum wilfordii

A novel actinobacterial strain, SB3-45T, was isolated from soil of Cynanchum wilfordii rhizosphere, Jaecheon-si, Chungcheongbuk-do, Republic of Korea. Strain SB3-45T, was Gram-stain-positive, aerobic and coccoid to short rod-shaped bacterium. Growth occurred at 4–37 °C (optimum 28 °C), pH 5–8 (optimum pH 7) and 0–2.5 % NaCl (optimum 0%). Phylogenetic analysis based on 16S rRNA gene sequence showed that strain SB3-45T belonged to the genus Nocardioides and was closely related to Nocardioides opuntiae OS-21T (96.2%) and Nocardioides panacihumi Gsoil 616T (95.9%). ll-DAP as the diamino acid in the peptidoglycan and the menaquinone MK-8(H4) as the predominant isoprenoid quinone were detected. The polar lipids of strain SB3-45T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and unidentified phospholipid. The major cellular fatty acids (>5%) of strain SB3-45T were iso-C16 : 0, C18 : 1 ω9c and C17 : 0. Based on phylogenetic, physiological and chemotaxonomic characteristics, strain SB3-45T represents a novel species of the genus Nocardioides, for which the name Nocardioides cynanchi sp.nov. is proposed. The type strain is SB3-45T (=KCTC 49133T=NBRC 114107T).