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.