ABSTRACT
Aa a characteristic medicinal plant in China, Gentiana rigescens Franch. has the function of protecting the liver and invigorating the spleen. At present, there are a few studies on the content determination method of characteristic components of G. rigescens, so it is necessary to establish a scientific and effective quality control method; In this study, The high performance liquid chromatography (HPLC) fingerprint of G. rigescens was established, based on literature reviewed and characteristic spectrum identified, the source range of G. rigescens quality marker (Q-marker) was screened. The effectiveness of the ingredients and the corresponding targets and pathways was analyzed through network pharmacology, and drew the diagram of ''component-target-pathway''. Qualitative and quantitative analysis of G. rigescens was performed by HPLC, and screen the main marker components leading to the differences between groups which were determined the Q-marker of G. rigescens; The literature and HPLC had determined that five iridoids were the main source of G. rigescens Q-marker. The network pharmacology (effectiveness) and qualitative and quantitative (detectability) analysis of G. rigescens from different producing areas confirmed that gentiopicroside, swertiamarin, and sweroside can be used as the main landmark components, and there were significant differences in their contents among different producing areas; The analysis of G. rigescens from different producing areas was carried out by network pharmacology and chemical fingerprints, it is confirmed can be used as potential Q-marker to provide sufficient theoretical basis for the quality control of G. rigescens in the later period.
ABSTRACT
ObjectiveThe law of fertilizer requirement serves as the basis for the fertilization of medicinal plants， development of special fertilizer， and high-quality medicinal materials. MethodThis study aims to explore the optimal potassium application rate for Panax ginseng to achieve high yield and quality of the medicinal material and targeted management of potassium fertilizer. To be specific， 6 concentration gradients （0， 2， 4， 8， 10， and 12 mmol·L-1） of potassium sulfate （potassium fertilizer） were designed and applied to the 4-year-old P. ginseng in CK， C1， C2， C3， C4， and C5 treatments， respectively. Thereby， the influence of potassium concentration on P. ginseng was observed. ResultWhen potassium sulfate was applied at 8 mmol·L-1， P. ginseng had the chlorophyll content of 32.13%， net photosynthetic rate of 2.548 8 µmol·m-2·s-1， and activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） significantly higher than those in the CK， C1， C4， and C5 treatments （P<0.05）. The average fresh weight of P. ginseng roots was 6.25 g， 134% up from the CK， and the content of ginsenoside Rg1 （5.24 mg·g-1） and Re （4.17 mg·g-1） and total saponins （12.33 mg·g-1） was significantly higher than that in CK and other treatments （P<0.05）. Thus， 8 mmol·L-1 potassium sulfate was most favorable for the growth and effective component accumulation of four-year-old P. ginseng. ConclusionThis study expounds the effect of potassium fertilizer on the yield and quality of P. ginseng， which is expected to help guide the precise application of potassium fertilizer in P. ginseng production in the field and lay a theoretical basis for the development of special fertilizer for P. ginseng and the optimization of fertilization technology.
ABSTRACT
Isopentenyl diphosphate isomerase (IDI) is a key enzyme in the regulation of triterpenes biosynthesis and plays an important role in ginsenoside biosynthesis. In this study, two IDI genes, PvfIDI1 (GenBank No. MZ736417) and PvfIDI2 (GenBank No. MZ736418) were cloned from Panax vietnamensis var. fuscidiscus. The open reading frame of both PvfIDI1 and PvfIDI2 was 924 bp encoding 307 amino acids. The molecular weights of PvfIDI1 and PvfIDI2 were 34.84 kDa and 34.66 kDa, respectively, with theoretical pIs of 6.01 and 5.66. Bioinformatic analysis indicated that PvfIDI1 and PvfIDI2 contained two conserved sequences: TNTCCSHPL and WGEHELDY. Phylogenetic analysis showed that PvfIDI1 and PvfIDI2 were closely related to Panax notoginseng IDI. Expression analysis showed that both PvfIDI1 and PvfIDI2 genes are expressed in root, rhizome, stem and leaf of P. vietnamensis var. fuscidiscus. However, PvfIDI1 is highly expressed in the rhizome and PvfIDI2 is highly expressed in the stem. PvfIDI1 and PvfIDI2 recombinant proteins were expressed in E. coli; a functional coloration experiment showed that PvfIDI1 and PvfIDI2 could promote the accumulation of lycopene, indicating that both PvfIDI1 and PvfIDI2 encode functional IDI enzymes. The cloning and functional studies on PvfIDI1 and PvfIDI2 provide a foundation for the further study of IDI and the regulation of ginsenoside biosynthesis in P. vietnamensis var. fuscidiscus.
ABSTRACT
Objective:To investigate the physiological response of Ginseng Radix et Rhizoma with different phenotypes to high light stress under farmland cultivation mode， and to provide theoretical support for breeding of and fine management of new varieties of farmland ginseng. Method:Four-year-old ginseng plants with different stem colors were used as materials， and blue film was replaced by the colorless and translucent film for performing high light stress and investigating the change of growth status， light response curve， photosynthetic and fluorescence parameters of ginseng leaves. Meanwhile， the physiological adaptability and cell ultrastructural differences of ginseng with different phenotypes for strong light were compared by analyzing the variation of leaf ultrastructural characteristics before and after the stress. Result:The color of ginseng leaves became weak and the content of chlorophyll was greatly decreased with burning phenomenon on the leaf margin under high light stress. The maximum net photosynthetic rate and light saturation point of purple-stem ginseng were higher than those of green-stem ginseng. Transpiration rate， water use efficiency and other gas exchange parameters of purple-stem ginseng had adversity advantages， photosynthetic electron transport rate， maximum photochemical efficiency， photochemical quenching coefficient and other chlorophyll fluorescence parameters were higher than those of green-stem ginseng. There were changes in ultrastructure of the two germplasms， and the plasmolysis of green-stem ginseng was more obvious， its chloroplast membrane ruptured， the contents were exuded and the accumulation of starch grains and osmiophilic bodies increased. The chloroplast membrane structure of purple-stem germplasm was relatively stable， and its number of multivesicular bodies increased significantly by comparing with that of green-stem ginseng under high light. Conclusion:High light stress inhibits the leaf growth of farmland ginseng with different stem colors. The photosynthetic efficiency of green-stem ginseng is obviously reduced， and the integrity of chloroplast is damaged， leading to the weak physiological resistance. The purple-stem ginseng can reduce the damage of the photosynthetic system of plants under high light stress by its special cell structure and non-photochemical quenching advantages. Therefore， the purple-stem ginseng can be cultivated into a new resistant variety.
ABSTRACT
Objective: To clone the squalene epoxidase genes of Panax vietnamensis var. fuscidiscus(PvfSE),and perform bioinformatics analysis and prokaryotic expression. Method: Total RNA was extracted from root of P. vietnamensis var. fuscidiscus by trizol method, and reverse-transcribed into first stand of cDNA. Specific primers for PvfSE cloning were designed according to the transcriptome data of P. vietnamensis var. fuscidiscus,and the cDNA sequence of PvfSE gene was isolated. Bioinformatics of PvfSE was analyzed by relevant software. The prokaryotic expression vector pMal-c2X-PvfSE was built to express recombinant protein in Escherichia coli cells. Result: The PvfSE gene contained a 1 887 bp open reading frame,encoding a predicted protein of 628 amino acids. The calculated molecular weight was 68.8 kDa,the theoretical isoelectric point was 9.28,the aliphatic index was 95.18,the grand average of hydropathicity was -0.060, and the instability index was 40.36. The protein was unstable. Bioinformatics analysis showed that PvfSE had two transmembrane domains and no signal peptide. PvfSE was most likely to be located in chloroplast or cytoplasmic membrane. PvfSE was a mixed protein with FAD/NAD(P) binding domain and squalene epoxidase domain. Sequence alignment and phylogenetic analysis demonstrated that PvfSE had a relatively close relationship with CpSE1,CpSE3,OsSE1 and OsSE2,which was involved in the biosynthesis of triterpene saponins in Cucurbita pepo and Ononis spinosa. In addition,PvfSE protein was expressed in E. coli. Conclusion: In this study,PvfSE gene was cloned and expressed in BL21(DE3),which lays a foundation for the further study on the gene functions of PvfSE and the biosynthetic pathway of triterpenoid saponins in P. vietnamensis var. fuscidiscus.
ABSTRACT
Polyphyllin is the main active constituent in Paris which was a traditional Chinese medicine. In order to evaluate the quality of Paris rapidly and ensure the efficacy in clinical therapy, we quantified the contents of polyphyllin Ⅰ, polyphyllin Ⅱ and polyphyllin Ⅶ using infrared spectroscopy with partial least squares regression(PLSR). The method for evaluating the quality of Paris was established. Infrared spectra of 78 samples from various species in different origins were collected. The contents of polyphyllin Ⅰ, Ⅱ and Ⅶ were determined by high performance liquid chromatography(HPLC). The HPLC data were combined with the spectral data to predict the contents of three polyphyllin rapidly. Multiplicative signal correction(MSC), standard normal variate(SNV), orthogonal signal correction(OSC), first derivative and second derivative were utilized for the spectral preprocessing. Then, the optimized spectral data were used to establish the quantitative prediction model based on PLSR. The results showed that the best spectral pretreatment of polyphyllin Ⅰ and Ⅱ were MSC+OSC+2nd Der and that of polyphyllin Ⅶ was MSC+SNV+OSC+2nd Der. In the quantitative calibration model, the determination coefficients (R²) of polyphyllin Ⅰ, polyphyllin Ⅱ and polyphyllin Ⅶ were 0.930 8, 0.934 8 and 0.912 3, respectively while the Root mean square error of estimation(RMSEE) were 1.855 0, 0.632 3 and 0.001 6 mg•g⁻¹, respectively. In the verification model, the R² of polyphyllin Ⅰ, polyphyllin Ⅱ and polyphyllin Ⅶ were 0.948 8, 0.703 6 and 0.801 7, respectively, and the root mean square error of prediction(RMSEP)were 1.704 6, 1.227 8 and 0.002 0 mg•g⁻¹, respectively. Because of the predictive value of quantitative model was closed to the real value, the effect of the model was good. The model of polyphyllin Ⅰ and Ⅱ were better than that of polyphyllin Ⅶ. The developed method was non-destructive, fast, and accurate. It was feasible to determine the content of polyphyllin in Paris.