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.

Drought and ultravioletB (UVB) radiation affect secondary metabolite accumulation in medicinal plants, but their combined effects on saikosaponin biosynthesis in Bupleurum chinense are unknown. This study we integrated physiological measurements (hormone contents, saikosaponin quantification) with transcriptomic and metabolomic profiles of responses of B. chinense to drought, UV-B, and their combination. Seedlings were treated with 10% polyethylene glycol (PEG)-6000 to simulate drought, UV-B radiation, or both. Physiological characteristics, phytohormone contents, and transcriptomic and metabolomic profiles were analyzed.,Drought significantly promoted saikosaponin accumulation, whereas UV-B inhibited it. Under combined stress, saikosaponin contents exceeded control levels but remained below those under drought alone, indicating partial antagonism by UV-B. Integrated analyses identified α-linolenic acid metabolism and plant hormone signal transduction as the principal pathways underlying stress-dependent regulation of saikosaponin accumulation. Drought markedly altered jasmonic acid (JA)-associated gene expression, while salicylic acid (SA) accumulation positively correlated with saikosaponin content. Pearson correlation analysis identified ACAA1 (Cluster-13225.99126) as a candidate gene associated with jasmonoyl-isoleucine (JA-Ile) metabolism. Transcription factor analysis revealed the APETALA2/Ethylene Response Factor (AP2/ERF) family as the predominant stress-responsive transcription factor family across all treatments.,The results indicate that drought and UV-B activate phytohormone signaling, transcriptional responses, and metabolic reprogramming, but with different downstream outcomes. This work provides new insights into environmental regulation of saikosaponin accumulation and identifies candidate genes and pathways for future functional validation and molecular improvement.

Amidst increasing emphasis on environmental sustainability in agriculture, the eco-friendly biocontrol fungus Clonostachys rosea is gaining prominence. In this study, we report for the first time that the endophytic fungus C. rosea strain GU-9, isolated from Glycyrrhiza uralensis, can naturally overproduce riboflavin. We assessed the riboflavin production capacity of GU-9, elucidated its biosynthetic pathway, and investigated its effects on the host plant. Both GU-9 and another isolate, GU-D4, were morphologically and molecularly identified as C. rosea. Notably, GU-9 secreted copious amounts of a yellow pigment during cultivation, distinguishing it from GU-D4 and other documented C. rosea strains. UPLC-MS/MS analysis revealed that this pigment was riboflavin. After optimizing fermentation conditions, GU-9 achieved a riboflavin yield of 249.97 mg/L. Whole genome sequencing identified the putative complete riboflavin biosynthesis pathway in GU-9 and ten putative key enzyme-encoding genes. The expression of key genes (RIB3, RIB4, and RIB5) was significantly upregulated during the late cultivation stage, coinciding with a substantial increase in riboflavin yield. In plant-microbe interaction assays, GU-9 exhibited superior performance to GU-D4, significantly promoting the growth of suspension cells and seedlings and significantly increasing the accumulation of bioactive compounds in the host plant. Following Ashbya gossypii, GU-9 represents a newly discovered naturally occurring riboflavin overproducer among filamentous fungi. Unlike traditional biocontrol agents, GU-9 confers potent growth-promoting effects and enhances the accumulation of valuable bioactive compounds in plants, demonstrating its potential as a novel multifunctional biocontrol agent.

Xiangru, with Mosla chinensis (Mc, 2n = 18) and its considered cultivar M. chinensis 'Jiangxiangru' (McJ, 2n = 18) as original plants, is an annual herb of the Lamiaceae family, and is widely used as medicinal and edible plant due to its spleen strengthening function. However, absence of genomic resource impedes in-depth research towards Xiangru. In this study, the morphological characteristics and volatile organic compounds (VOC) contents of Mc and McJ were analyzed, showing higher trichome density and monoterpenoid accumulation obtained in Mc, whereas McJ possessed higher biomass. We assembled high-quality Mc, McJ, and their adulterant Mosla soochowensis (2n = 18) genomes of 426.1, 408.8, and 412.8 Mb, respectively, containing the repeat sequences of 57.17%, 56.33%, and 55.83%. Comparative genomics analysis indicated Mosla radiated ~13.3 Mya, supporting McJ initially as a natural naturally formed resource. Five monoterpene synthase genes were identified through comparative transcriptome and were responsible for catalyzing production of diversified monoterpene skeleton, in which TPS1 mediated formation of γ-terpinene, accompanied by CYP71D179 and SDR2, leading to the final production of carvacrol and thymol. We further explored correlation between monoterpenoids biosynthesis and trichome development, indicating MIXTA and WIN1 jointly regulate both trichome formation and VOC accumulation by directly binding promoters of TPS1 and CYP71D179, respectively. Our study fills vacancy of genus Mosla genomes, improving the biosynthetic and regulatory mechanism of volatile compounds in aromatic Traditional Chinese Medicine, also offering novel targets for quality-directed breeding in Xiangru.

The quality of Glycyrrhiza uralensis Fisch. (licorice) is influenced by a combination of abiotic factors and microbial interactions. Recent studies have demonstrated that root endophytes communicate closely with plants and can help increase the accumulation of secondary metabolites. However, the specific impact of this regulatory mechanism on licorice quality remains to be fully elucidated. In this study, the multi-omics techniques were employed to investigate the relationship between licorice endophytes and their metabolites. The findings revealed significant differences in the composition and function of endophytes in cultivated and wild licorice from the main and Dao-di production areas in China. Some specific root endophytes in wild licorice may be involved in regulating the contents of glycyrrhizic acid and flavonoids, which were important active substances in the host. Furthermore, a synthetic community (SynCom) of 12 bacterial strains and 11 fungal strains in different combinations was constructed to regulate the content of active substances in cultivated licorice. Then the SynCom was simplified to consist of five bacterial species, which was superior to the original SynCom and significantly promoted the accumulation of flavonoid components and triterpenoid components in cultivated licorice. The functions of these bacteria were related to the expression of key enzyme-encoding genes involved in the biosynthesis of host active ingredients. Our findins demonstrated that SynComs derived from wild licorice could suces sfully colonize and enhance the accumulation of flavonoids and glycyrrhizic acid in cultivated licorice. This underscores the potential of SynComs as precise regulators of medicinal plant quality, offering a promising avenue for optimizing the production of bioactive compounds in cultivated licorice.

Objective: To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch. (G. uralensis) and to improve the quality of cultivated G. uralensis for both medicine and food and aid in the increase in the content of effective components in G. uralensis. Methods: In this study, whole G. uralensis plants were treated with exogenous chitosan, and comprehensive analyses of secondary metabolites and proteins were conducted using liquid chromatography with tandem mass spectrometry and isobaric tag for relative and absolute quantitation, respectively. Effects of chitosan induction on endogenous hormones of G. uralensis were analyzed using an enzyme-linked immunosorbent assay. Gene ontology function annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation were conducted to study the effect of chitosan induction on the proteome. Results: Chitosan induction significantly increased the levels of flavonoids in G. uralensis; however, the variation in triterpenoids was not substantial. Biological processes, including photosynthesis, secondary metabolism, and abiotic stress responses, were significantly enriched. Additionally, the photosynthetic pathway, photosynthesis-antenna protein pathway, and plant hormone signal transduction pathway were significantly enriched. In the flavonoid biosynthesis pathway, the upstream-related enzyme phenylalanine ammonia-lyase (PAL) and the downstream-related enzymes chalcone synthase (CHS), polyketide reductase (PKR), chalcone isomerase (CHI), and vestitone reductase (VR) were significantly upregulated. Conclusions: Our findings suggest that chitosan induction may promote the tricarboxylic acid (TCA) cycle, and the TCA cycle enhancement significantly upregulated PAL, CHS, PKR, CHI, and VR, the five key enzymes involved in flavonoid synthesis of G. uralensis, indicating that chitosan induction activated the entire metabolic pathway associated with flavonoids in G. uralensis. Our findings provide a reference for improving the quality of cultivated G. uralensis from the perspective of pharmacodynamic components.

Andrographis paniculata is renowned for its wide range of pharmaceutical properties, largely owing to the presence of bioactive diterpenoids. However, the mechanism of methyl jasmonate (MeJA) -induced diterpenoid biosynthesis in A. paniculata remains poorly understood. In this study, we found that the MeJA-induced accumulation of diterpenoids was attributed to the increased expression of genes involved in diterpenoid biosynthetic pathways. Transient overexpression and Y1H assays revealed that ApMYC2, ApbZIP46, and ApWRKY33 were positive regulators that promoted the accumulation of diterpenoids by directly binding to the promoters of the downstream target gene ApUGT76E1. Thus, ApMYC2, ApbZIP46, and ApWRKY33 may be involved in the regulation of the diterpenoid biosynthesis pathway in A. paniculata. Overall, this research lays the groundwork for elucidating the molecular mechanism by which MYCs, bZIPs and WRKYs regulate the accumulation of diterpenoids in A. paniculata under MeJA induction. Our results provide a theoretical basis for the molecular breeding and quality improvement of A. paniculata in the future.

Isoliquiritigenin, a key pharmacologically active compound derived from the traditional Chinese medicine Glycyrrhizae Radix et Rhizoma, can be further modified into various high-value 5-deoxyflavones, demonstrating significant potential for pharmaceutical development. Currently, the supply of isoliquiritigenin primarily depends on plant extraction. However, heterologous synthesis using microbial cell factories presents a promising alternative, offering a solution to resource limitations caused by the dwindling availability of Glycyrrhiza uralensis . This study aimed to employ heterologous synthesis in yeast strains for the stable and high-efficiency production of isoliquiritigenin. First, a stable chassis strain for isoliquiritigenin production was constructed by integrating optimized biosynthetic pathway enzyme genes. A type IV noncatalytic chalcone isomerase-like protein and a synthetic protein scaffold system were employed to enhance the metabolic channeling of key pathway enzymes. Subsequently, yeast metabolism was fine-tuned to balance precursor supply, and cofactor engineering strategies were implemented to increase nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) availability, thereby ensuring the catalytic efficiency of the key enzyme chalcone reductase. The engineered strain Y21-2 achieved a 24.4-fold increase in isoliquiritigenin titer compared to the original strain. Additionally, the proportion of the by-product naringenin chalcone was reduced by 67.8%, marking the first instance in which the ratio of C-5 hydroxylated by-products was minimized to 10.4% during the microbial synthesis of 5-deoxyflavones. This work provides a valuable reference for the efficient and sustainable production of isoliquiritigenin, laying a solid foundation for further pathway optimization and the biotechnological synthesis of other high-value natural 5-deoxyflavones.

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.

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.

Coix seed is a good product for both medicinal and food use, which is highly susceptible to aflatoxin B1 (AFB1) contamination during field transport, storage, and processing. The aim of this study is to find microbial strains that can solve the problem of contamination of coix seed. In this study, the AFB1-degrading microorganism SX1-1 was isolated and identified as a Bacillus megaterium based on morphology, microscopy, and 16S rDNA sequencing. The optimum culture conditions for SX1-1 to degrade AFB1 were determined to be 12 h. The optimum degradation conditions were 72 h, 57°C, and an initial pH of 8.0. The highest degradation of AFB1 was observed in the fermentation supernatant of the SX1-1 strain, with a degradation rate of 97.45%. In addition, whole-genome sequencing analysis of this strain revealed the presence of a number of enzymes that could potentially degrade AFB1. Importantly, SX1-1 was able to degrade AFB1-contaminated coix seed in situ by 50.06% after co-culture. In conclusion, this strain had a high AFB1 degradation ability, and has great potential and great application as a biocontrol agent for AFB1 degradation of coix seed.

This study aims to evaluate the in vivo function of Fusarium oxysporum in Glycyrrhiza uralensis by salt tolerance,indoleacetic acid(IAA)production capacity,phosphate-dissolving capacity,and iron carrier production capacity.The stable genetic transformation system of the F.oxysporum was established by Agrobacterium tumefaciens-mediated genetic transformation(ATMT)technology,and the stability and staining efficiency of transformants were detected by the cloning of the marker gene green fluorescent protein(GFP)and the efficiency of β-glucuronidase staining(GUS).Efficient and stable transformants were selected for restaining G.uralensis and evaluating its influence on the growth of the G.uralensis seedlings.The results show that F.oxysporum has good salt tolerance and could still grow on potato glucose agar(PDA)medium containing 7% sodium chloride,but the growth rate slows down with the increase in sodium chloride content in PDA medium.F.oxysporum has the function of producing indoleacetic acid,and the concentration of IAA in its fermentation broth is about 3.32 mg·mL-1.In this study,the genetic transformation system of F.oxysporum is successfully constructed,and the ATMT system is efficient and stable.One transformant with both high staining efficiency and genetic stability is selected,and the restaining rate of the transformant in G.uralensis is 76.92%,which could significantly improve the main root length of one-month-old G.uralensis seedlings and promote the growth and development of G.uralensis seedlings.The results of this study can lay the foundation for the development of biological bacterial fertilizer and the growth regulation of high-quality G.uralensis.

Inductively coupled plasma mass spectrometry was employed to determine the content of 25 inorganic elements in Bambusae Concretio Silicea, and the elemental fingerprint was established according to the element content. SPSS 20.0 and SIMCA 14.1 were used for chemometric analysis. A total of 25 elements were detected in Bambusae Concretio Silicea, including boron(B), sodium(Na), magnesium(Mg), aluminum(Al), potassium(K), calcium(Ca), scandium(Sc), vanadium(V), chromium(Cr), manganese(Mn), iron(Fe), cobalt(Co), nickel(Ni), copper(Cu), zinc(Zn), gallium(Ga), arsenic(As), selenium(Se), zirconium(Zr), molybdenum(Mo), cadmium(Cd), indium(In), barium(Ba), plumbum(Pb), and bismuth(Bi), among which 13 elements were quantitative. The top three elements in terms of average content were K&gt;Fe&gt;Na, and the content of B, Na, Al, Ca, Fe, and Ba varied in different batches of Bambusae Concretio Silicea samples from different origins. The correlation coefficient between Ca and Mg was the highest, followed by that between Mn and Zn, both of which showed significant positive correlations. Therefore, it was hypothesized that there was a synergistic incremental relationship between Ca and Mg as well as between Mn and Zn. According to the results of principal component analysis, Fe, As, Ni, Cu, Mn, Na, Mg, Ca, Al, Ba, and B were the main elements of Bambusae Concretio Silicea. According to the results of orthogonal partial least squares-discriminant analysis, Cu, As, and Mn were the common differential elements of three origins, which suggested that the quantitative identification of Cu, As, and Mn could roughly distinguish the three batches of Bambusae Concretio Silicea samples. This study analyzed the elements and their content in different batches of Bambusae Concretio Silicea samples, aiming to provide theoretical support for exploring the pharmacodynamic material basis and mechanism of Bambusae Concretio Silicea and lay a foundation for the quality evaluation, safe application, and resource development and utilization of Bambusae Concretio Silicea.

The content of 15 total amino acids(TAAs) in Bambusae Concretio Silicea was determined by HPLC with phenyl-isothiocyanate(PITC) for pre-column derivatization. The results showed that the content of TAA was 0.61-12.25 mg·g~(-1), and aspartic acid(Asp), glutamic acid(Glu), proline(Pro), glycine(Gly), and valine(Val) were the top five amino acids in terms of the average content. The content of essential amino acids(EAAs), conditionally essential amino acids(CEAAs), non-essential amino acids(NEAAs), and medicinal amino acids(MAAs) was 0.24-4.75, 0.30-4.73, 0.40-7.50, and 0.36-6.51 mg·g~(-1), respectively. Among the delicious amino acids, sweet amino acids(SAA), bitter amino acids(BAA), fresh-taste amino acids(FAAs), and odourless amino acids(OAAs) had the content of 0.22-4.70, 0.19-4.03, 0.13-2.26, and 0.06-1.26 mg·g~(-1), respectively. The 21 batches of Bambusae Concretio Silicea samples presented the same composition but significant differences in the content of amino acids. Among the three producing areas, Guangdong was the area where the samples had the highest content of TAAs, EAAs, CEAAs, NEAAs, MAAs, and delicious amino acids. Furthermore, the ratio of amino acid(RAA), ratio coefficient of amino acid(RCAA), and score of ratio coefficient of amino acid(SRCAA) were calculated to evaluate the nutritional value of Bambusae Concretio Silicea. The results showed that the Bambusae Concretio Silicea samples from Guangdong had better nutritional value. The nutritional value evaluation based on the content of 15 amino acids was proposed to provide data support for the quality grading of Bambusae Concretio Silicea and lay a foundation for the development and utilization of the medicinal material resources.

Acute promyelocytic leukemia (APL) is marked by a block at the promyelocyte stage. Treatments like ATRA and ATO face resistance and relapse issues. Plastrum testudinis, a traditional Chinese medicine, may offer therapeutic potential. This study investigated xtr-miR-22-3p from P. testudinis for treating APL. High expression of xtr-miR-22-3p was confirmed, with target prediction indicating interactions with key genes, including PML. xtr-miR-22-3p reduced HL-60 leukemia cell growth, altered the cell cycle, and selectively inhibited HL-60 proliferation while promoting BMSC growth, suggesting its potential as a targeted APL therapy.

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.

IntroductionScutellaria baicalensis is rich in bioactive flavonoid, which are widely used in clinical therapy. Many environmental factors, such as water and temperature, affect gene expression and secondary metabolites accumulation in plants.MethodsIn this study, to explore the effect of drought stress on the accumulation of flavonoids and gene expression in S. baicalensis seedlings, 4-week-old Scutellaria baicalensis seedlings were treated with different concentrations of PEG6000 to simulate drought stress. The contents of four root-specific flavones (baicalein, wogonin, baicalin, and wogonoside) in samples under different treatments were quantitatively analyzed by high performance liquid chromatography (HPLC). The expression levels of flavonoid biosynthesis-related genes (PAL1, PAL2, CHS, and UBGAT) were determined by real-time quantitative PCR (qRT-PCR). Also, a correlation analysis between flavonoid contents and gene expression levels was made.ResultsThe HPLC results revealed that 5 and 10% PEG6000 treatments significantly increased the content of four flavonoids, with 5% PEG 6000 treatment being the most beneficial to the flavonoids accumulation. The qRT-PCR results showed that PAL2 and CHS gene expressions differed significantly in different organs, while PAL1 and UBGAT had poor organ-specific. For genes in roots, the expression of PAL1 and UBGAT was the highest in 5% PEG6000 treatment, and PAL2 and CHS were the highest in 10% PEG6000 treatment. Compared with other concentrations of PEG6000, 5 and 10% PEG6000 were more advantageous for gene expression. Collectively, PEG6000 at a low concentration promoted the accumulation of flavonoids and the expression of related genes. Additionally, the correlation results demonstrated that PAL1, PAL2, CHS, and UBGAT genes in roots stimulated the formation and accumulation of the four flavonoids to varying degrees, while the exception of PAL2 gene expression in roots was negatively correlated with wogonin content.DiscussionThis study for the first time investigated the effect of drought stress on the downstream gene UBGAT in S.baicalensis seedlings as well as the correlation between gene expression and flavonoid content in S. baicalensis seedlings under drought stress, providing a new sight for studying the effects of drought stress on flavonoid accumulation and related gene expression in S. baicalensis.

For thousands of years, corn silk has been widely used as an antidiabetic, antioxidant, and antihyperlipidemic and for other effects, but there is a lack of studies that correlate the extracts of flavonoid composition with their biological activities. Thus, the objectives of this study were to optimize the conditions for extracting flavonoids, identify flavonoids, and correlate the flavonoid composition with the biological activities in corn silk. The response surface experiments showed that the highest flavonoid content was predicted at 45.321 min, 57.349°C, 26.089 mL/g, and 71.269%, respectively. The verification experiment results under these optimized conditions showed an ultrasonic time of 45 min, an ultrasonic temperature of 57°C, a liquid-to-material ratio of 26, and an ethanol volume fraction of 70%. No significant differences (the relative error is 4.378%) were observed between the theoretical and experimental TFC values, indicating that the developed models were accurate. Under these optimum extraction conditions, 20 major compounds were identified and quantified by UPLC-LTQ/Orbitrap MS. Furthermore, these optimum ethanol extracts of corn silk are effective against Bacillus subtilis and hypoglycemic activity compared with the traditional heating reflux extraction method. Six corn silk components seem to be the main contributors to the inhibitory effect against Bacillus subtilis and hyperglycemia activities. These results are useful for the application of corn silk in the food or pharmaceutical industry.

Drought adaptation of plants is closely related to resistance and tolerance to drought stress as well as the ability to recover after the elimination of the stress. Glycyrrhiza uralensis Fisch is a commonly applied herb whose growth and development are greatly affected by drought. Here, we provide the first comprehensive analysis of the transcriptomic, epigenetic, and metabolic responses of G. uralensis to drought stress and rewatering. The hyper-/hypomethylation of genes may lead to up-/downregulated gene expression, and epigenetic changes can be regarded as an important regulatory mechanism of G. uralensis under drought stress and rewatering. Moreover, integrated transcriptome and metabolome analysis revealed that genes and metabolites involved in pathways of antioxidation, osmoregulation, phenylpropanoid biosynthesis, and flavonoid biosynthesis may regulate the drought adaptation of G. uralensis. This work provides crucial insights into the drought adaptation of G. uralensis and offers epigenetic resources for cultivating G. uralensis with high drought adaptation.

Plant-produced coumarins have been shown to play an important role in assembly of the plant microbiomes and iron acquisition. Coumarins can also be produced by some microorganisms.