Metabolome and transcriptome analyses identify the plant immunity systems that facilitate sesquiterpene and lignan biosynthesis in Syringa pinnatifolia Hemsl.

Abstract

Background Syringa pinnatifolia Hemsl. is a shrub belonging to the Oleaceae family. The peeled woody stems and roots of S. pinnatifolia are used in Chinese traditional medicine. This plant has been used for centuries, and modern pharmacological research has revealed its medicinal value. However, the wild populations of S. pinnatifolia have been decreasing, and it has been listed as an endangered plant in China. To elucidate the molecular mechanism leading to the synthesis of the major components of S. pinnatifolia for its further development and sustainable use, this study compared peeled stems and twigs at the metabolic and molecular levels. Results Peeled stems with the purple substance visible (SSP) and peeled twigs without the purple substance (TSP) were compared at different levels. Microscopic observation showed resin-like fillers in SSP and wood fiber cell walls approximately 1.0 μm thicker than those in TSP (wood fiber cell thickness approximately 2.7 μm). In addition, 104 volatile organic compounds and 870 non-volatile metabolites were detected in the non-targeted and widely-targeted metabolome analyses, respectively. Among the 76 differentially accumulated metabolites (DAMs) detected, 62 were up-accumulated in SSP. Most of these DAMs were terpenes, of which 90% were identified as sesquiterpenes in the volatile organic compound analysis. In the analysis of the non-volatile metabolites, 21 differentially accumulated lignans were identified, of which 18, including five subtypes, were accumulated in SSP. RNA sequencing revealed 4,421 upregulated differentially expressed genes (DEGs) and 5,522 downregulated DEGs in SSP compared with TSP, as well as 33,452 genes that were not differentially expressed. Analysis of the DEGs suggested that sesquiterpenes and lignans were mostly biosynthesized via the mevalonate and phenylpropanoid pathways, respectively. Additionally, in SSP, the enriched Gene Ontology terms included response to biotic stimulus and defense response, while the enriched Kyoto Encyclopedia of Genes and Genomes pathways included plant–pathogen interaction and many other pathways related to plant immunity. Conclusions This study provides metabolome and transcriptome information for S. pinnatifolia, suggesting that biotic stimuli, including pathogens, are potential and valuable approaches to promoting the biosynthesis of the metabolites linked to the medicinal properties of this plant.

Syringenes M – Q, Eremophilane Sesquiterpenoid Dimers from the Peeled Stems ofSyringa pinnatifolia

“…The 1 H-and 13 C-NMR data (Tables 1 and 2) showed high similarity to 2. Analysis of the spectroscopic data showed the presence of a sp 3 (Δδ C + 82.1), and further corroborated by the observed HMBCs from H-1' to C-3' and C-5', thus establishing its planar structure. NOESY correlations between H 3 -13 and H 3 -13', along with those of H 3 -13'/ H 3 -15 and H 3 -13/H 3 -15, revealed these protons were co-facial (Figure 5).…”

“…[1] The peeled roots, stems, and twigs have long been used as a traditional Mongolian medicine in local for treating cardiovascular symptoms, asthma, pain, and fever. [2] Although listed as one of the third-level national endangered plants in China, [3] SP is attracting attention from researchers because of its well-known clinical efficiency in Inner Mongolia and anti-acute myocardial infarction effect in modern research. [4 -9] Previous studies revealed that terpenoids in particular sesquiterpenoids are the most representative constituents of SP, [10 -14] and more than 10 types of sesquiterpenoids have been described from SP so far, including humulane, eremophilane, caryophyllane, and pinnatane, which are specific constituents used to distinguish SP from other Syringa species.…”

Ionomic Combined with Transcriptomic and Metabolomic Analyses to Explore the Mechanism Underlying the Effect of Melatonin in Relieving Nutrient Stress in Apple

“…Ascorbic acid also enhances the resistance to drought stress [ 41 ]. In addition, lignin is the main component of the cell walls of vascular plants; it promotes lignification and enhances the ability of plants to resist stress, such as enhancing the resistance of Zea mays to leaf blight and gray spot [ 32 , 42 ]. Melatonin acts as the first line of defense against oxidative stress in the internal and external environments.…”

Isolation and identification of endophytic fungi involved in the promotion of sesquiterpene accumulation in Syringa pinnatifolia

“…For volatile metabolome analysis of calli samples, the headspace–solid-phase microextraction–gas chromatography–mass spectrometry method was used, as previously described. [6]…”