The saponins found in Panax japonicus, a traditional medicinal herb in Asia, exhibit high degrees of structural and functional similarity. In this study, metabolite analysis revealed that oleanolic acid-type and dammarane-type saponins were distributed unevenly in three tissues (rhizome_Y, rhizome_O, and secRoot) of P. japonicus. Single-molecule real-time (SMRT) sequencing and next generation sequencing (NGS) data revealed distinct and tissue-specific transcriptomic patterns relating to the production of these two types of saponins. In the co-expression network and hierarchical clustering analyses, one 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and two 1-deoxy-D-xylulose-5-phosphate synthase (DXS) etc. transcripts were found to be key genes associated with the biosynthesis of oleanolic acid and dammarane-type saponins in P. japonicus, respectively. In addition, cytochrome p450 (CYP) and UDP-glucuronosyltransferase (UGT) family proteins that serve as regulators of saponin biosynthesis-related genes were also found to exhibit tissue-specific expression patterns. Together these results offer a comprehensive metabolomic and transcriptomic overview of P. japonicus.
Biosynthesis, Full-length transcriptome, Metabolome, Panax japonicus, Rhizoma and root tissues, Saponin distribution
Xu R, Zhang J, You J, Gao L, Li Y, Zhang S, Zhu W, Shu S, Xiong C, Xiong H, Chen P, Guo J, Liu Z. Full-Length Transcriptome Sequencing and Modular Organization Analysis of Oleanolic Acid- and Dammarane-Type Saponins Related Gene Expression Patterns in Panax Japonicus. Genomics. 2020; 112(6). doi: 10.1016/j.ygeno.2020.06.045.