Biogenic Synthesis and Spatial Distribution of Endogenous Phytohormones and Ginsenosides Provide Insights on Their Intrinsic Relevance in Panax ginseng

Abstract

Ginseng, the root and rhizome of Panax ginseng C. A. Mey., is a well-known and valuable traditional Chinese medicine. The pharmacological activities of ginseng are mainly attributed to the presence of ginsenosides, which are considered to be critical biomarkers for evaluating ginseng quality. The biosynthesis of triterpenes, which serve defensive functions in plants, is regulated by endogenous phytohormones that play key roles in growth and defense of plant populations. However, the role of major hormones that are closely related to secondary metabolism pathways in P. ginseng is poorly understood. To gain insight into their potential correlation, we performed a spatial synthesis analysis and studied the distribution of endogenous phytohormones and ginsenosides in different tissue regions of the entire P. ginseng plant. Gibberellins are growth hormones that accumulate in the fiber root. In contrast, abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA), which are considered stress hormones, were predominantly found in the leaf and leaf peduncle. We observed a tissue-specific distribution of phytohormones consistent with the expression of genes involved in hormone biosynthesis that influenced ginsenoside synthesis and distribution. The aim of this study was to investigate the role of different endogenous phytohormones on triterpene metabolites in ginseng innate immunity.

The chromosome-level reference genome assembly for Dendrobium officinale and its utility of functional genomics research and molecular breeding study

“…However, there is still a limited of comprehensive analysis that underlying the synthesis of active ingredients in Dendrobium species. Salicylic acid, functions as a signaling molecule, could be applied to enhance the accumulation of active ingredients in medical plants 78 . Therefore, to investigate the biosynthesis of three main active ingredients in D. officinale , including polysaccharides, alkaloids and flavonoids, the expression of candidate genes was analyzed by coupling the high-quality genome sequence generated here with RNA-Seq studies under SA stress.…”

Transcriptome analysis reveals that jasmonic acid biosynthesis and signaling is associated with the biosynthesis of asperosaponin VI in Dipsacus asperoides

“…Asperosaponin VI is a triterpenoid saponin, and thus it is biosynthesized via the mevalonic acid (MVA) pathway which has been found in previous studies (Yang et al, 2017;Chen et al, 2018;Yang et al, 2018). Typically, the pathway involves the conversion of isoprenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) into farnesyl pyrophosphate (FPP), which then generates squalene and 2,3-oxidosqualene, and is followed by a series of reactions involving cyclization, oxidation, hydroxylation and glycosylation (Kuzuyama, 2002;Augustin et al, 2011;Niu et al, 2014), which is accompanied by a variety of enzymatic reactions involving various enzymes such as farnesyl pyrophosphate synthase (FPPS), b-amyrin synthase (b-AS), and dammarenediol synthase (DS).…”

“…Complex secondary metabolic regulation processes exist in Chinese herbal plants. Genomes have been used to elucidate the metabolic processes in some important plants, such as Panax ginseng Xu et al, 2017Panax notoginseng (Wei et al, 2017Chen et al, 2018;Jiang et al, 2020), and Tripterygium wilfordii (Tu et al, 2020). With the rapid development of sequencing technology, transcriptome sequencing has emerged as a rapid method for researching the regulation and molecular mechanisms of complex growth and development processes, especially for D. asperoides, which lacks a reference genome.…”

Discovery of plant chemical defence mediated by a two-component system involving β-glucosidase in Panax species

“…During evolution, P. notoginseng deploys an enormous array of specialized secondary metabolites that help them solve pathogen attacks. Dammarane triterpenoid saponins with 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT) aglycon moieties, referred to as ginsenosides, perform defensive functions in plants 14 and are also the main pharmacological components of P. notoginseng 15 . These ginsenosides are distributed in various parts of P. notoginseng plants, such as rhizomes, roots, leaves, inflorescences, and infructescences 16,17 .…”