Spatiotemporal expression analysis of jasmonic acid and saponin-related genes uncovers a potential biosynthetic regulation in Panax notoginseng.

BACKGROUND: Sanqi, the root of Panax notoginseng, has long been recognized for its therapeutic effects on cardiovascular diseases. Saponins, including ginsenosides and notoginsenosides, are the main bioactive components of P. notoginseng. The biosynthesis of saponins is closely related to the defense responses orchestrated by endogenous hormones. RESULTS: To provide new insights into the underlying role of phytohormone jasmonic acid (JA) in the synthesis and regulation of saponins, we performed an ultra-performance liquid chromatography analysis of different tissues of P. notoginseng aged 2-4 years. Moreover, by combined evaluation of saponin content and transcriptome profiling of each tissue, the spatial and temporal distribution of saponins was analyzed. N notoginsenoside R1, ginsenoside Rb1 and ginsenoside Rd accumulated in the underground tissues, including the root, tuqi, fibril and rhizome. In agreement with this data, the corresponding genes of the endogenous hormone JAs, especially coronatine insensitive 1 (COI1) and myelocytomatosis proteins 2 (MYC2), were predominantly expressed in the underground tissues. The tissue- and age-specific distribution of saponins was consistent with the expression of genes involved in JA biosynthetic, metabolic and signaling pathways. CONCLUSION: The present study has revealed the temporal and spatial effects of endogenous phtohormones in the synthesis and regulation of notoginsenosides, which will provide a significant impact on improving the ecological planting technology, cultivating new high-quality varieties and protecting the rare resources of medicinal P. notoginseng. © 2024 Society of Chemical Industry.

[Seed morphology and germination characteristics of Tripterygium wilfordii].

The seeds of Tripterygium wilfordii are characterized by dormancy and a long germination cycle under natural sowing conditions. In this study, we developed a method for rapid germination of T. wilfordii seeds by analyzing the size, morphology, thousand-grain weight, viability, moisture content, physicochemical properties, and seed germination rates under different germination conditions. The seeds of T. wilfordii were fine columnar with a thick and hard outer seed coat. They had the length of 6.69 mm, the width of 2.14 mm, the thickness of 1.68 mm, the thousand-grain weight of 8.99 g, the moisture content of 8.86%, the soluble sugar content of 21.3 mg·g~(-1), the starch content of 28.9 mg·g~(-1), the soluble protein content of 44.2 mg·g~(-1), and the seed viability of only 54.0%. The seeds were respectively treated with distilled water, ultrasonication, low-temperature storage, 50 ℃ water, 100 mg·L~(-1) 6-BA, 0.6% KMnO_4, 1% KNO_3, 50 mg·L~(-1) NAA, and 100 mg·L~(-1) GA_3 solution. The results showed that soaking the seeds in 100 mg·L~(-1) GA_3 solution significantly promoted the germination. Further, the seeds were soaked in 50, 100, 250, 500, and 1 000 mg·L~(-1) GA_3 solutions, which demonstrated that high concentration(500 mg·L~(-1), 1 000 mg·L~(-1)) of GA_3 solutions increased the germination rate and speed and shortened the germination cycle from more than 3 months to less than 15 days. The findings of this study are of great significance to the breeding of T. wilfordii and lay a foundation for the large-scale propagation of T. wilfordii seeds and the excavation of T. wilfordii germplasm resources.

Isolation and characterization of a glycosyltransferase with specific catalytic activity towards flavonoids from Tripterygium wilfordii.

Flavonoids are important secondary metabolites that exist in many medicinal plants. Flavonoid glycosyltransferases can transfer sugar moieties to their parent rings, producing various flavonoid glycosides with significant pharmacological activities. Here, we report the molecular cloning of the O-glycosyltransferase TwUGT2 from Tripterygium wilfordii and its catalytic activity was explored by heterologous expression in E. coli. The results showed that TwUGT2 has specific glycosyltransferase activity towards C-3 and 7 hydroxyl groups of flavonoids, thereby converting quercetin and pinocembrin into isoquercitrin and pinocembrin 7-O-beta-D-glucoside, respectively. The identification of TwUGT2 will provide a useful molecular tool for synthetic biology and contribute to drug discovery.[Formula: see text].

[Effect of GR24 on accumulation of diterpenoids in Tripterygium wilfordii suspension cells].

Terpenoids are main bioactive components in Tripterygium wilfordii,but the contents of some terpenoids are relatively low. In order to provide scientific evidence for the regulation of terpenoids in T. wilfordii,this research explored the effect of GR24 on accumulations of four diterpenoids( triptolide,tripterifordin,triptophenolide,and triptinin B) in T. wilfordii suspension cells by biological technology and UPLC-QQQ-MS/MS. The results indicated that 100 µmol·L-1 GR24 inhibited the accumulations of triptolide,tripterifordin,triptophenolide,and triptinin B to different degrees. Compared with the control group,the contents of 4 diterpenoids( in the induced group) were down to 96.59%,63.80%,61.02% and 33.59% in 240 h,respectively. Among them,the accumulation of triptinin B iswas significantly inhibited. In addition,the key time point of inhibitory effect was 120 h after induction with GR24 in some diterpenoids. This is the first systematic study focusing on the effect of GR24 on the accumulations of diterpenoids in T. wilfordii suspension cells. The dynamic accumulation ruleregularity of four diterpenoids after induced by GR24 was summarized,which laid a foundation for further study on the chemical response mechanism of terpenoids to GR24.

[Molecular authentication of Jinyinhua formula granule by using allele-specific PCR].

Traditional authentication method is hard to identify herb's authenticity of traditional Chinese medicine(TCM) formula granules because they have lost all their morphological characteristics. In this study, a new allele-specific PCR method was established for identifying the authentication of Jinyinhua formula granule (made from Lonicerae Japonicae Flos) based on an SNP site in trnL-trnF fragment. Genomic DNA was successfully extracted from Lonicerae Japonicae Flos and its formula granules by using an improved spin column method and then PCR was performed with the designed primer. Approximately 110 bp specific bands was obtained only in the authentic Lonicerae Japonicae Flos and its formula granules, while no bands were found in fake mixed products. In addition, the PCR product sequence was proved from Lonicerae Japonicae Flos trnL-trnF sequence by using BLAST method. Therefore, DNA molecular authentication method could make up the limitations of character identification method and microscopic identification, and quickly identify herb's authenticity of TCM formula granules, with enormous potential for market supervision and quality control.

[Cloning and protein expression analysis of geranyl diphosphate synthase genes in Tripterygium wilfordii].

Based on the transcriptome data, the study cloned full-length cDNA of TwGPPS1 and TwGPPS2 genes from Tripterygium wilfordii suspension cells and then analyzed the bioinformation of the sequence and protein expression. The cloned TwGPPS1 has a 1 278 bp open reading frame (ORF) encoding a polypeptide of 425 amino acids. The deduced isoelectric point (pI) was 6.68, a calculated molecular weight was about 47.189 kDa. The full-length cDNA of the TwGPPS2 contains a 1 269 bp open reading frame (ORF) encoding a polypeptide of 422 amino acids. The deduced isoelectric point (pI) was 6.71, a calculated molecular weight was about 46.774 kDa.The entire reading frame of TwGPPS1,2 was cloned into the pET-32a(+) vector and expressed in E. coli BL21 (DE3) cells to obtain the TwGPPS protein, which laid a basis for further study on the regulation of terpenoid secondary metabolism and biological synthesis.