Transcriptomics Reveals the Molecular Basis for Methyl Jasmonate to Promote the Synthesis of Monoterpenoids in Schizonepeta tenuifolia Briq.

BACKGROUND: Methyl jasmonate has an important effect on the synthesis of plant secondary metabolites. Schizonepeta tenuifolia Briq. has a wide range of pharmacological effects and the secondary metabolites are dominated by monoterpenes (pulegone, menthone). OBJECTIVE: It is essential to determine the changes in secondary metabolites in S. tenuifolia under methyl jasmonate treatment and to probe the molecular mechanism. This can improve the accumulation of secondary metabolites in the medicinal plant S. tenuifolia and enrich the information gene expression at different MeJA levels, which can help to elucidate the molecular mechanism of monoterpenoid synthesis in S. tenuifolia. METHODS: In this study, we determined the changes in the content of monoterpenoids in S. tenuifolia under methyl jasmonate treatment. Meanwhile, we established a transcriptome database of S. tenuifolia under methyl jasmonate level using high-throughput sequencing. RESULTS: A certain concentration of MeJA promoted the accumulation of monoterpenoids in S. tenuifolia. The transcriptome database of S. tenuifolia leaves under 0, 50, 100 and 250 µM MeJA treatment was established. We generated 88,373 unigenes with an N50 length of 2678 bp, of which 50,843 (57.53%) can be annotated in at least one database. Compared with the CK (0 µM) group, 12,557 (50 µM), 15,409 (100 µM) and 13,286 (250 µM) differentially expressed genes were identified. GO and KEGG enrichment analysis revealed that JA signal transduction and monoterpenoid synthesis were the two most significant enrichment pathways. The expression levels of related DEGs involved in JA signaling and monoterpenoid synthesis were significantly up-regulated by MeJA. In addition, our phenotypic and differentially expressed gene association analysis revealed that monoterpenoid biosynthesis in S. tenuifolia was more associated with genes involved in plant trichome branching, phytohormone signaling and transcriptional regulation. CONCLUSIONS: This study confirmed that methyl jasmonate significantly promoted monoterpenoid biosynthesis in S. tenuifolia. A large number of genes responding to methyl jasmonate were associated with JA signaling and monoterpenoid biosynthesis.

Exploration of Antimicrobial Ingredients in Psoralea corylifolia L. Seed and Related Mechanism against Methicillin-Resistant Staphylococcus aureus.

With the abuse of antibiotics, bacterial antibiotic resistance is becoming a major public healthcare issue. Natural plants, especially traditional Chinese herbal medicines, which have antibacterial activity, are important sources for discovering potential bacteriostatic agents. This study aimed to develop a fast and reliable method for screening out antimicrobial compounds targeting the MRSA membrane from Psoralea corylifolia Linn. seed. A UPLC-MS/MS method was applied to identify the prenylated flavonoids in major fractions from the extracts of Psoralea corylifolia Linn. seed. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of different fractions and compounds. The morphological and ultrastructural changes of MRSA were determined by scanning electron microscopy (SEM). The membrane-targeting mechanism of the active ingredients was explored by membrane integrity assays, membrane fluidity assays, membrane potential assays, ATP, and ROS determination. We identified eight prenylated flavonoids in Psoralea corylifolia Linn. seed. The antibacterial activity and mechanism studies showed that this type of compound has a unique destructive effect on MRSA cell membranes and does not result in drug resistance. The results revealed that prenylated flavonoids in Psoralea corylifolia Linn. seeds are promising candidates for the development of novel antibiotic agents to combat MRSA-associated infections.

Identification and expression analysis of the WRKY gene family in Isatis indigotica.

The WRKY proteins, which represent one of the largest families of transcriptional regulators in plants, play pivotal roles in regulating multiple processes of growth and development, particularly in diverse stress responses. Isatis indigotica is widely used in Traditional Chinese Medicine and is famous for its use as a dye for the color indigo. However, reports of the WRKY gene family in I. indigotica are limited. In this study, 64 IiWRKY genes encoding proteins with the complete WRKY domain were identified from genome of I. indigotica. Based on their structure and phylogenetic relationships of this gene family in I. indigotica, the IiWRKY genes were classified into three groups: Group I (n = 13), Group II (n = 35) and Group III (n = 16). Sequence alignment revealed that IiWRKY proteins harbored two variants, WRKYRQK and WRKYGKK, of the highly conserved WRKYGQK motif. The number of exons in IiWRKY genes varied from two to 14, with most of IiWRKY genes containing three exons. Investigation of gene duplication demonstrated that 10 and 14 IiWRKY genes were incorporated in tandem and segmental duplication events, respectively. Finally, the expression profiles derived from transcriptome data and quantitative real-time PCR analysis showed distinct expression patterns of these IiWRKY gene in five different organs or in response to four abiotic stresses. Taken together, our results will contribute to functional analysis of IiWRKY genes, and also provide a basis for further clarification of the molecular mechanism of stress responses in this important herb.

An integrated antioxidant activity fingerprint for commercial teas based on their capacities to scavenge reactive oxygen species.

An integrated antioxidant activity fingerprint, based on on-line screening methods for three reactive oxygen species (ROS: superoxide anion radical, hydrogen peroxide, and hydroxyl radical) was developed to comprehensively evaluate the quality of 12 batches of commercial tea. High-performance liquid chromatography (HPLC) coupled with a chemiluminescent detector was used to determine the antioxidant characteristics of a selection of teas as bioactivity fingerprints. An HPLC-electrospray ionization-mass spectrometry analysis was used to determine the chemical profiles of the teas in the chromatographic fingerprints. All of the green teas (S01-S08) were better scavengers of the three ROS compared to the oolong teas (S09-S12). The main scavengers of the three ROS in green tea were 5-galloylquinic acid, (-)-epigallocatechin-3-O-gallate, and (-)-epicatechin-3-O-gallate, whereas in oolong tea, they were (-)-epigallocatechin-3-O-gallate and (-)-epigallocatechin. This study demonstrates that comprehensive fingerprinting is a potentially meaningful method for evaluating the quality of food products.

Impact of parameter fluctuations on the performance of ethanol precipitation in production of Re Du Ning Injections, based on HPLC fingerprints and principal component analysis.

The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections, including concentrate density, concentrate temperature, ethanol content, flow rate and stir rate in the addition of ethanol, precipitation time, and precipitation temperature. Under the experimental and simulated production conditions, a series of precipitated resultants were prepared by changing these variables one by one, and then examined by HPLC fingerprint analyses. Different from the traditional evaluation model based on single or a few constituents, the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis (PCA) to comprehensively assess the performance of ethanol precipitation. Our results showed that concentrate density, ethanol content, and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants. The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products.

The integrated quality assessment of Chinese commercial dry red wine based on a method of online HPLC-DAD-CL combined with HPLC-ESI-MS.

AIM: To apply an integrated quality assessment strategy to investigate the quality of multiple Chinese commercial dry red wine samples. METHOD: A comprehensive method was developed by combining a high performance liquid chromatography-diode array detector-chemiluminescence (HPLC-DAD-CL) online hyphenated system with an HPLC-ESI-MS technique. RESULTS: Chromatographic and H2O2-scavenging active fingerprints of thirteen batches of different, commercially available Chinese dry red wine samples were obtained and analyzed. Twenty-five compounds, including eighteen antioxidants were identified and evaluated. The dominant and characteristic antioxidants in the samples were identified. The relationships between antioxidant potency and the cultivated variety of grape, producing area, cellaring period, and trade mark are also discussed. CONCLUSION: The results provide the feasibility for an integrated quality assessment strategy to be efficiently and objectively used in quality (especially antioxidant activity) assessment and identification of dry red wine.

The Spectrum-Effect integrated fingerprint of Polygonum cuspidatum based on HPLC-diode array detection-flow injection-chemiluminescence.

AIM: To establish the Spectrum-Effect integrated fingerprint of Polygonum cuspidatum to evaluate the quality of P. cuspidatum. METHODS: An on-line HPLC-DAD-flow injection chemiluminescence (FICL) method was developed to investigate the quality of P. cuspidatum from different habitats based on the established Spectrum-Effect integrated fingerprint. RESULTS: Nineteen batches of samples of P. cuspidatum were evaluated for the similarity of their chromatographic and free radical scavenging fingerprints, and the results compared. Main antioxidants were estimated by regression analysis between peak areas of thirteen compounds and their activities. Some active compounds were identified by HPLC-ESI-MS. CONSULSIONS: The results indicated that main antioxidants in P. cuspidatum could be rapidly screened by the established Spectrum-Effect integrated fingerprint based on on-line HPLC-DAD-FICL, and would be more efficient and objective method to evaluate the quality of P. cuspidatum.