Guangxi Ren

Medicine food homology (MFH) plants are rich in nutrients and bioactive specialized metabolites, and their endophytic fungi mediate key biotransformation of host secondary metabolites. Licorice, a representative MFH herb, accumulates glycyrrhizin (GL) as its dominant bioactive triterpenoid saponin. Its hydrolysates glycyrrhetinic acid (GA) and glycyrrhetinic acid 3-O-mono-β-D-glucuronide (GAMG) show stronger bioactivity and bioavailability than GL. However, the enzymatic mechanisms of licorice-derived endophytic fungi-mediated GL biotransformation remain unclear. Here, nine licorice endophytic fungi were screened for significant GL-inducible β-glucuronidase activity. Four functional GH2 β-glucuronidase were obtained by prokaryotic and eukaryotic expression systems, and confirmed to catalyze glycyrrhizin biotransformation via two distinct hydrolytic pathways. Inoculation of these four strains into licorice markedly enhanced host glycyrrhizin accumulation. This study provides novel enzymatic resources for the efficient bioproduction of high-value glycyrrhizin derivatives, and proposes a green strategy to improve glycyrrhizin content in licorice, deepening the understanding of endophyte–host metabolic crosstalk in medicinal herbs.

Bupleurum, a plant of the genus Bupleurum L. in the family Umbelliferae, is prevalent and extensively applied in traditional medicine systems across East and Southeast Asian countries for the treatment of colds, malaria, hepatitis and other diseases. In the current Chinese herbal medicine market, only the dried roots of two species, Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd., are authentic herbs, and their cultivars dominate as the commercial source, contributing to about 80% of the market share. Shanxi Province, known as the suitable habitat for Bupleurum in China, has a diverse ecosystem and geographical areas with diverse environmental conditions. These diversity ecosystem and environmental conditions cause prominent variations in the content of active ingredients of Bupleurum L. across different sites. Therefore, analyze the ecological, geographical, and soil factors that influence the quality of Bupleurum and to recommend the best suitable sites for cultivation of Bupleurum. This study demonstrates a close correlation between the quality of Shanxi Bupleurum sp. and different ecological factors. A total of 70 sets of Bupleurum and soil samples were collected from 25 counties across 6 cities in Shanxi Province. Consequently, the saponin contents of Datong, Shuozhou and Yizhou were generally higher than those of Linfen, Jincheng and Yuncheng. Bupleurum from northern Shanxi exhibits higher saikosaponin content compared to that from southern Shanxi; The total content of the five saponins shows a significant positive correlation with longitude (*P < 0.05) and a highly significant positive correlation with latitude and altitude (**P < 0.01). Saikosaponin levels positively correlate with latitude, longitude, and altitude; Meanwhile, the significance ranking of these ecological factors is: monthly average temperature is equal to monthly average surface temperature is greater than monthly sunshine hours. Low temperatures, arid conditions, and longer sunlight exposure are optimal conditions for the accumulation of saponin components; Besides, high-saponin Bupleurum is typically cultivated in low alkaline soils with low nitrogen, while the habitat of Shanxi Bupleurum is differentiated into four regions. Overall, the current study presents a foundation for selecting the best cultivation sites for Bupleurum and provides a valuable reference for evaluating other medicinal herb production regions.

Baicalein is a unique flavonoid compound with important pharmacological activities, derived from Scutellaria baicalensis Georgi. Baicalein, as the aglycone of baicalin, is a key form for exerting pharmacological activity in vivo. β-glucuronidases (GUSs) are the enzymes involved in the conversion of baicalin to baicalein. In this study, the content of baicalein in S. baicalensis was significantly increased by 20.44% after treatment with 5% PEG6000. Seven GUSs from the glycoside hydrolase 79 family were identified through comparative transcriptome analysis. Among them, GUS1 and GUS2 were confirmed to have catalytic activity in converting baicalin to baicalein in prokaryotic and eukaryotic systems. The correlation analysis further revealed a significant positive correlation of 0.962 (p < 0.01) between the expression of GUS2 and baicalein content in six different sources of S. baicalensis. Interestingly, the presence of variable sites in the GUS1 and GUS2 genes significantly affected their catalytic efficiency in the S. baicalensis samples from the six geographic origins. These findings also provide valuable GUS biological enzyme resources for the effective synthesis of baicalein and offer new insights into the accumulation pattern of baicalein in S. baicalensis.

The plant microbiome is one of the key determinants of healthy plant growth. However, the complexity of microbial diversity in plant microenvironments in different regions, especially the relationship between subsurface and aboveground microorganisms, is not fully understood. The present study investigated the diversity of soil microorganisms in different regions and the diversity of microorganisms within different ecological niches, and compared soil microorganisms and endophytic microorganisms. 16 S and ITS sequencing was used to sequence the soil and endophytes microbiome of honeysuckle. Alpha diversity analysis and principal component analysis (PCoA) were used to study the soil and endophyte microbial communities, and the function of endophyte bacteria and fungi was predicted based on the PICRUST2 process and FUNGuild. In total, there were 382 common bacterial genera and 139 common fungal genera in the soil of different producing areas of honeysuckle. There were 398 common bacterial genera and 157 common fungal genera in rhizosphere soil. More beneficial bacteria were enriched in rhizosphere soil. Endophytic bacteria were classified into 34 phyla and 770 genera. Endophytic fungi were classified into 11 phyla and 581 genera, among which there were significant differences in the dominant genera of roots, stems, leaves, and flowers, as well as in community diversity and richness. Endophytic fungal functions were mainly dominated by genes related to saprophytes, functional genes that could fight microorganisms were also found in KEGG secondary functional genes. More beneficial bacteria were enriched in rhizosphere soil of honeysuckle, and the microbial network of the rhizosphere is more complex than that of the soil. Among the tissues of honeysuckle, the flowers have the richest diversity of endophytes. The endogenous dominant core bacteria in each part of honeysuckle plant have a high degree of overlap with the dominant bacteria in soil. Functional prediction suggested that some dominant core bacteria have antibacterial effects, providing a reference for further exploring the strains with antibacterial function of honeysuckle. Understanding the interaction between honeysuckle and microorganisms lays a foundation for the study of growth promotion, quality improvement, and disease and pests control of honeysuckle from the perspective of microorganisms.

Asari Radix et Rhizoma is commonly used in classic prescriptions of herbal medicine in several Asian countries for resuscitation, pain relief, and sore treatment, and Asarum heterotropoides (A. heterotropoides) is an important source material of Asari Radix et Rhizoma. However, the plants of the Asari Radix et Rhizoma and some plants in Asarum spp. contain aristolochic acid I (AAI), which is considered as a carcinogen. The objective of the current study is to detoxify Asarum spp. through microbial degradation of AAI in order to ensure drug safety. Based on the observation of the close correlation between endophytic fungi of A. heterotropoides and AAI, we identified an AAI-degrading fungus and screened for candidate genes involved in AAI degradation. Full-length O-demethylase genes (ODMs) were cloned including A.h-ODM-5, Fs-ODM-4, and Fs-ODM-1, and their ability to degrade AAI was tested in vitro. The results showed that the AAI-degrading fungus was identified as Neocosmospora solani (A.h-Fs-1, endophytic fungi of A. heterotropoides), and verified the capability of specific O-demethylation to modify the structure of AAI. We further identified the functional ODMs in A.h-Fs-1 capable of degrading AAI and uncovered the AAI degradation mechanism of A.h-Fs-1. The microbial degradation of AAI demonstrated in the present study offers a new method to detoxify plant materials used for herbal medicine, and would enhance the regulation of toxic ingredients content in herbal medicine source materials.

Poria cocos (PC) is an important fungus with high medicinal and nutritional values. However, the quality of PC is heavily dependent on multiple factors in the cultivation regions. Traditional methods are not able to perform quality evaluation for this fungus in a short time, and a new method is needed for rapid quality assessment. Here, we used near-infrared (NIR) spectroscopy combined with chemometric method to identify the cultivation regions and determine PC chemical compositions. In our study, 138 batches of samples were collected and their cultivation regions were distinguished by combining NIR spectroscopy and random forest method (RFM) with an accuracy as high as 92.59%. In the meantime, we used partial least square regression (PLSR) to build quantitative models and measure the content of water-soluble extract (WSE), ethanol-soluble extract (ASE), polysaccharides (PSC) and the sum of five triterpenoids (SFT). The performance of these models were verified with correlation coefficients (R²_cal and R²_pre) above 0.9 for the four quality parameters and the relative errors (RE) of PSC, WSE, ASE and SFT at 4.055%, 3.821%, 4.344% and 3.744%, respectively. Overall, a new approach was developed and validated which is able to distinguish PC production regions, quantify its chemical contents, and effectively evaluate PC quality.

Licorice is one of the most generally used herbal medicines in the world; however, wild licorice resources have decreased drastically. Cultivated Glycyrrhiza uralensis Fischer are the main source of licorice at present, but the content of main active components in cultivated G. uralensis are lower than in wild G. uralensis. Therefore, the production of high-quality cultivated G. uralensis is an urgent issue for the research and production fields. In this study, the content of five active components and seven endogenous phytohormones in cultivated G. uralensis (two-year-old) were determined by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, different concentrations (25–200 mg/L) of exogenous abscisic acid (ABA) were sprayed on the leaves of G. uralensis in the fast growing period. Results showed that ABA, zeatin riboside (ZR), and dihydrozeatin riboside (DHZR) had strong correlation with active components. In addition, the content of five active components increased remarkably after ABA treatment. Our results indicate that ABA is significantly related to the accumulation of active components in G. uralensis, and the application of exogenous ABA at the proper concentration is able to promote the accumulation of main components in G. uralensis.

The traditional medicine licorice is the most widely consumed herbal product in the world. Although much research work on studying the changes in the active compounds of licorice has been reported, there are still many areas, such as the dynamic accumulation of secondary metabolites in licorice, that need to be further studied. In this study, the secondary metabolites from licorice under two different methods of stress were investigated by ultra-high-performance liquid chromatography coupled with hybrid linear ion trap–Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS). A complex continuous coordination of flavonoids and triterpenoids in a network was modulated by different methods of stress during growth. The results showed that a total of 51 secondary metabolites were identified in licorice under ABA stress. The partial least squares–discriminate analysis (PLS-DA) revealed the distinction of obvious compounds among stress-specific districts relative to ABA stress. The targeted results showed that there were significant differences in the accumulation patterns of the deeply targeted 41 flavonoids and 10 triterpenoids compounds by PCA and PLS-DA analyses. To survey the effects of flavonoid and triterpenoid metabolism under ABA stress, we inspected the stress-specific metabolic changes. Our study testified that the majority of flavonoids and triterpenoids were elevated in licorice under ABA stress, while the signature metabolite affecting the dynamic accumulation of secondary metabolites was detected. Taken together, our results suggest that ABA-specific metabolite profiling dynamically changed in terms of the biosynthesis of flavonoids and triterpenoids, which may offer new trains of thought on the regular pattern of dynamic accumulation of secondary metabolites in licorice at the metabolite level. Our results also provide a reference for clinical applications and directional planting and licorice breeding.

So far there exists no corresponding quality test procedures and grading standards for the seed of Prunus humilis, which is one of the important source of base of semen pruni. Therefor we set up test procedures that are adapt to characteristics of the P. humilis seed through the study of the test of sampling, seed purity, thousand-grain weight, seed moisture, seed viability and germination percentage. 50 cases of seed specimens of P. humilis tested. The related data were analyzed by cluster analysis. Through this research, the seed quality test procedure was developed, and the seed quality grading standard was formulated. The seed quality of each grade should meet the following requirements: for first grade seeds, germination percentage ≥ 68%, thousand-grain weight 383 g, purity ≥ 93%, seed moisture ≤ 5%; for second grade seeds, germination percentage ≥ 26%, thousand-grain weight ≥ 266 g, purity ≥ 73%, seed moisture ≤9%; for third grade seeds, germination percentage ≥ 10%, purity ≥ 50%, thousand-grain weight ≥ 08 g, seed moisture ≤ 13%.