Advances in Mechanism Research on Polygonatum in Prevention and Treatment of Diabetes.

Diabetes mellitus is a fast-growing disease with a major influence on people's quality of life. Oral hypoglycemic drugs and insulin are currently the main effective drugs in the treatment of diabetes, but chronic consumption of these drugs has certain side effects. Polysaccharides, saponins, flavonoids, and phenolics are the primary secondary metabolites isolated from the rhizomes of Polygonatum sibiricum Redouté [Asparagaceae], Polygonatum kingianum Collett & Hemsl [Asparagaceae], or Polygonatum cyrtonema Hua [Asparagaceae], which have attracted much more attention owing to their unique therapeutic role in the treatment and prevention of diabetes. However, the research on the mechanism of these three Polygonatum spp. in diabetes has not been reviewed. This review provides a summary of the research progress of three Polygonatum spp. on diabetes and its complications, reveals the potential antidiabetic mechanism of three Polygonatum spp., and discusses the effect of different processed products of three Polygonatum spp. in treating diabetes, for the sake of a thorough understanding of its effects on the prevention and treatment of diabetes and diabetes complications.

Transcriptome Analysis of Different Sections of Rhizome in Polygonatum sibiricum Red. and Mining Putative Genes Participate in Polysaccharide Biosynthesis.

As a traditional Chinese herb, the rhizomes of Polygonatum sibiricum Red. are rich in various compounds which have plenty of pharmacological applications and biological activities. Among them, Polygonatum sibiricum polysaccharides (PSP) are the main active ingredients and exhibit a broad range of pharmacological. Based on previous researches, identifying genes involved in PSP biosynthesis will help delineate such pathway at the molecular level. In that case, we performed RNA sequencing analysis for two sections of P. sibiricum Red.'s rhizomes significantly different in PSP content. A total of 435,858 unigenes were obtained by assembling transcripts from both sections and 29,548 (6.77%) ones were annotated in all seven public databases. Analyzing count data of RNA-seq, 13,460 differential expression genes (DEGs) between two sections of rhizomes were acquired. After DEGs were mapped to KEGG databases, twelve represented KEGG pathways related to PSP biosynthesis were summed up. And most DEGs were assigned to the pathway of "Starch and sucrose metabolism". Finally, seventeen candidate genes whose expression levels were related to the polysaccharide content, were considered involving PSP biosynthesis in P. sibiricum Red. The present study lays a foundation of researching the molecular mechanisms of PSP biosynthesis.

Evaluation of genetic diversity and construction of DNA fingerprinting in Polygonatum Mill. based on EST-SSR and SRAP molecular markers.

Polygonatum sibiricum is widely consumed as a traditional Chinese herb and edible plant in China. Despite its nutritional and medical values, research on Polygonatum Mill. has been scarce, particularly as far as its genetic diversity is concerned. In this study, fourteen expressed sequence tag-derived simple sequence repeat (EST-SSR) and seven sequence-related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversity in fifty Polygonatum Mill. accessions. The EST-SSRs and SRAPs produced 173 (90.58%) and 113 (93.39%) polymorphic bands, respectively. Unweighted Pair-Group Method Analysis (UPGMA) based on the combined data matrices of EST-SSRs and SRAPs divided the fifty Polygonatum Mill. accessions into fourteen groups. In addition, accessions of P. cyrtonema Hua obtained from Anhui and Zhejiang provinces were clustered according to their geographic origin. Furthermore, some accessions were gathered together based on species, such as P. kingianum Coll. et Hemsl, P. punctatum Royle ex Kunth, P. odoratum (Mill.) Druce, and P. sibiricum Red., and bootstrap analysis for clustering fully supported the grouping of the accessions. The Analysis of Molecular Variance (AMOVA) results revealed higher variation within populations (95%) rather than among populations (5%), indicating that Polygonatum Mill. has a low genetic differentiation between populations, and Principal Coordinate Analysis (PCoA) greatly supported the results of cluster analysis and AMOVA analysis. Finally, five markers which could produce abundant and stable bands were used to construct DNA fingerprinting database of Polygonatum Mill.. Our results demonstrated the utility of both EST-SSR and SRAP markers to successfully evaluate and identify Polygonatum Mill..