Identification and expression analysis of expansin gene family in Salvia miltiorrhiza.

BACKGROUND: Expansins (EXP) are important enzymes that are involved in the extension of plant cells and regulation of root configurations, which play important roles in resisting various stresses. As a model medicinal plant, Salvia miltiorrhiza is well recognized for treating coronary heart disease, myocardial infection, and other cardiovascular and cerebrovascular diseases; however, the SmEXP gene family has not yet been analyzed. METHODS: The SmEXP family was systematically analyzed using bioinformatics. Quantitative real-time PCR was employed to analyze the tissue expression patterns of the SmEXP family, as well as its expression under abscisic acid (ABA) treatment and abiotic stress. Subcellular localization assay revealed the localization of SmEXLA1, SmEXLB1, and SmEXPA2. RESULTS: This study identified 29 SmEXP that belonged to four different subfamilies. SmEXP promoter analysis suggested that it may be involved in the growth, development, and stress adaptation of S. miltiorrhiza. An analysis of the expression patterns of SmEXP revealed that ABA, Cu2+, and NaCl had regulatory effects on its expression. A subcellular localization assay showed that SmEXLA1 and SmEXLB1 were located on the nucleus and cell membrane, while SmEXPA2 was located on the cell wall. CONCLUSION: For this study, the SmEXP family was systematically analyzed for the first time, which lays a foundation for further elucidating its physiological and biological functionality.

Characteristics of CXE family of Salvia miltiorrhiza and identification of interactions between SmGID1s and SmDELLAs.

Carboxylesterase (CXE) is a class of hydrolases that contain an α/ß folding domain, which plays critical roles in plant growth, development, and stress responses. Based on the genomic and transcriptomic data of Salvia miltiorrhiza, the SmCXE family was systematically analyzed using bioinformatics. The results revealed 34 SmCXE family members in S. miltiorrhiza, and the SmCXE family could be divided into five groups (Group I, Group II, Group III, Group IV, and Group V). Cis-regulatory elements indicated that the SmCXE promoter region contained tissue-specific and development-related, hormone-related, stress-related, and photoresponsive elements. Transcriptome analysis revealed that the expression levels of SmCXE2 were highest in roots and flowers (SmCXE8 was highest in stems and SmCXE19 was highest in leaves). Further, two GA receptors SmCXE1 (SmGID1A) and SmCXE2 (SmGID1B) were isolated from the SmCXE family, which are homologous to other plants. SmGID1A and SmGID1B have conserved HGGSF motifs and active amino acid sites (Ser-Asp-Val/IIe), which are required to maintain their GA-binding activities. SmGID1A and SmGID1B were significantly responsive to gibberellic acid (GA3) and methyl jasmonate (MeJA) treatment. A subcellular assay revealed that SmCXE1 and SmCXE2 resided within the nucleus. SmGID1B can interact with SmDELLAs regardless of whether GA3 exists, whereas SmGID1A can only interact with SmDELLAs in the presence of GA3. A Further assay showed that the GRAS domain mediated the interactions between SmGID1s and SmDELLAs. This study lays a foundation for further elucidating the role of SmCXE in the growth and development of S. miltiorrhiza.

Efficacy of rhizobacteria Paenibacillus polymyxa SY42 for the biological control of Atractylodes chinensis root rot.

Atractylodes chinensis is one of the most commonly used bulk herbs in East Asia; however, root rot can seriously affect its quality and yields. In contrast to chemical pesticides, biological control strategies are environmentally compatible and safe. For this study, 68 antagonistic bacterial strains were isolated from the rhizospheres of healthy Atractylodes chinensis. Strain SY42 exhibited the most potent fungicidal activities, with inhibition rates against F. oxysporum, F. solani, and F. redolens of 67.07 %, 63.40 % and 68.45 %, respectively. Through morphological observation and molecular characterization, strain SY42 was identified as Paenibacillus polymyxa. The volatile organic components (VOCs) produced by SY42 effectively inhibited the mycelial growth of pathogenic fungi through diffusion. SY42 significantly inhibited the germination of pathogenic fungal spores. Following co-culturing with SY42, the mycelium of the pathogenic fungus was deformed, folded, and even ruptured. SY42 could produce cellulases and proteases to degrade fungal cell walls. Pot experiments demonstrated the excellent biocontrol efficacy of SY42. This study revealed that P. polymyxa SY42 inhibited pathogenic fungi through multiple mechanisms, which verified its utility as a biocontrol agent for the control of A. chinensis root rot.

Comprehensive Functional Analysis of the bZIP Family in Bletilla striata Reveals That BsbZIP13 Could Respond to Multiple Abiotic Stresses.

Basic leucine zipper (bZIP) transcription factors (TFs) are one of the largest families involved in plant physiological processes such as biotic and abiotic responses, growth, and development, etc. In this study, 66 members of the bZIP family were identified in Bletilla striata, which were divided into 10 groups based on their phylogenetic relationships with AtbZIPs. A structural analysis of BsbZIPs revealed significant intron-exon differences among BsbZIPs. A total of 63 bZIP genes were distributed across 16 chromosomes in B. striata. The tissue-specific and germination stage expression patterns of BsbZIPs were based on RNA-seq. Stress-responsive expression analysis revealed that partial BsbZIPs were highly expressed under low temperatures, wounding, oxidative stress, and GA treatments. Furthermore, subcellular localization studies indicated that BsbZIP13 was localized in the nucleus. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays suggested that BsbZIP13 could interact with multiple BsSnRK2s. The results of this study provide insightful data regarding bZIP TF as one of the stress response regulators in B. striata, while providing a theoretical basis for transgenic and functional studies of the bZIP gene family in B. striata.

Integrative analysis of transcriptome and metabolome reveals the sesquiterpenoids and polyacetylenes biosynthesis regulation in Atractylodes lancea (Thunb.) DC.

Atractylodes lancea (Thunb.) is a perennial medicinal herb, with its dry rhizomes are rich in various sesquiterpenoids and polyacetylenes components (including atractylodin, atractylon and ß-eudesmol). However, the contents of these compounds are various and germplasms specific, and the mechanisms of biosynthesis in A. lancea are still unknown. In this study, we identified the differentially expressed candidate genes and metabolites involved in the biosynthesis of sesquiterpenoids and polyacetylenes, and speculated the anabolic pathways of these pharmaceutical components by transcriptome and metabolomic analysis. In the sesquiterpenoids biosynthesis, a total of 28 differentially expressed genes (DEGs) and 6 differentially expressed metabolites (DEMs) were identified. The beta-Selinene is likely to play a role in the synthesis of atractylon and ß-eudesmol. Additionally, the polyacetylenes biosynthesis showed the presence of 3 DEGs and 4 DEMs. Notably, some fatty acid desaturase (FAB2 and FAD2) significantly down-regulated in polyacetylenes biosynthesis. The gamma-Linolenic acid is likely involved in the biosynthesis of polyacetylenes and thus further synthesis of atractylodin. Overall, these studies have investigated the biosynthetic pathways of atractylodin, atractylon and ß-eudesmol in A. lancea for the first time, and present potential new anchor points for further exploration of sesquiterpenoids and polyacetylenes compound biosynthesis pathways in A. lancea.

Systematic Identification and Functional Analysis of the Hypericum perforatum L. bZIP Gene Family Indicating That Overexpressed HpbZIP69 Enhances Drought Resistance.

Basic leucine zipper (bZIP) transcription factors play significant roles in plants' growth and development processes, as well as in response to biological and abiotic stresses. Hypericum perforatum is one of the world's top three best-selling herbal medicines, mainly used to treat depression. However, there has been no systematic identification or functional analysis of the bZIP gene family in H. perforatum. In this study, 79 HpbZIP genes were identified. Based on phylogenetic analysis, the HpbZIP gene family was divided into ten groups, designated A-I and S. The physicochemical properties, gene structures, protein conserved motifs, and Gene Ontology enrichments of all HpbZIPs were systematically analyzed. The expression patterns of all genes in different tissues of H. perforatum (i.e., root, stem, leaf, and flower) were analyzed by qRT-PCR, revealing the different expression patterns of HpbZIP under abiotic stresses. The HpbZIP69 protein is localized in the nucleus. According to the results of the yeast one-hybrid (Y1H) assays, HpbZIP69 can bind to the HpASMT2 (N-acetylserotonin O-methyltransferase) gene promoter (G-box cis-element) to activate its activity. Overexpressing HpbZIP69 in Arabidopsis wild-type lines enhanced their tolerance to drought. The MDA and H2O2 contents were significantly decreased, and the activity of superoxide dismutase (SOD) was considerably increased under the drought stress. These results may aid in additional functional studies of HpbZIP transcription factors, and in cultivating drought-resistant medicinal plants.

Structural characteristics of a novel Bletilla striata polysaccharide and its activities for the alleviation of liver fibrosis.

Liver fibrosis has proven to be the main predisposing factor for liver cirrhosis and liver cancer; however, an effective treatment remains elusive. Polysaccharides, with low toxicity and a wide range of bioactivities, are strong potential candidates for anti-hepatic fibrosis applications. For this study, a new low molecular weight neutral polysaccharide (B. striata glucomannan (BSP)) was extracted and purified from Bletilla striata. The structure of BSP was characterized and its activities for alleviating liver fibrosis in vivo were further evaluated. The results revealed that the structural unit of BSP was likely →4)-ß-D-Glcp-(1 â†’ 4)-ß-D-Manp-(1 â†’ 4)-ß-D-2ace-Manp-(1 â†’ 4)-ß-D-Manp-(1 â†’ 4)-ß-D-Glcp-(1 â†’ 4)-ß-D-Manp-(1 â†’ 4)-ß-D-Manp-(1 â†’ 4)-ß-D-3ace-Manp-(1→, with a molecular weight of only 58.5 kDa. Additionally, BSP was observed to attenuate the passive impacts of liver fibrosis in a manner closely related to TLR2/TLR4-MyD88-NF-κB signaling pathway conduction. In summary, the results of this study provide theoretical foundations for the potential applications of BSP as an anti-liver fibrosis platform.

Genome-Wide Characterization of B-Box Gene Family in Salvia miltiorrhiza.

B-box (BBX) is a type of zinc finger transcription factor that contains a B-box domain. BBX transcription factors play important roles in plant photomorphogenesis, signal transduction, as well as abiotic and biological stress responses. However, the BBX gene family of Salvia miltiorrhiza has not been systematically investigated to date. For this study, based on the genomic data of Salvia miltiorrhiza, 27 SmBBXs genes were identified and clustered into five evolutionary branches according to phylogenetic analysis. The promoter analysis suggested that SmBBXs may be involved in the regulation of the light responses, hormones, stress signals, and tissue-specific development. Based on the transcriptome data, the expression patterns of SmBBXs under different abiotic stresses and plant hormones were analyzed. The results revealed that the expressions of the SmBBXs genes varied under different conditions and may play essential roles in growth and development. The transient expression analysis implied that SmBBX1, SmBBX4, SmBBX9, SmBBX20, and SmBBX27 were in the nucleus. A transcriptional activation assay showed SmBBX1, SmBBX4, SmBBX20, and SmBBX24 had transactivation activities, while SmBBX27 had none. These results provided a basis for further research on the role of SmBBXs in the development of Salvia miltiorrhiza.

A Novel R2R3-MYB Transcription Factor SbMYB12 Positively Regulates Baicalin Biosynthesis in Scutellaria baicalensis Georgi.

Scutellaria baicalensis Georgi is an annual herb from the Scutellaria genus that has been extensively used as a traditional medicine for over 2000 years in China. Baicalin and other flavonoids have been identified as the principal bioactive ingredients. The biosynthetic pathway of baicalin in S. baicalensis has been elucidated; however, the specific functions of R2R3-MYB TF, which regulates baicalin synthesis, has not been well characterized in S. baicalensis to date. Here, a S20 R2R3-MYB TF (SbMYB12), which encodes 263 amino acids with a length of 792 bp, was expressed in all tested tissues (mainly in leaves) and responded to exogenous hormone methyl jasmonate (MeJA) treatment. The overexpression of SbMYB12 significantly promoted the accumulation of flavonoids such as baicalin and wogonoside in S. baicalensis hairy roots. Furthermore, biochemical experiments revealed that SbMYB12 is a nuclear-localized transcription activator that binds to the SbCCL7-4, SbCHI-2, and SbF6H-1 promoters to activate their expression. These results illustrate that SbMYB12 positively regulates the generation of baicalin and wogonoside. In summary, this work revealed a novel S20 R2R3-MYB regulator and enhances our understanding of the transcriptional and regulatory mechanisms of baicalin biosynthesis, as well as sheds new light on metabolic engineering in S. baicalensis.

Whole genome and transcriptome reveal flavone accumulation in Scutellaria baicalensis roots.

Scutellaria baicalensis Georgi is a medicinal plant in the Lamiaceae family that contains high levels of 4'-deoxyflavone and other flavonoids in its roots. Therefore, it has strong potential as a plant resource for researching the biosynthesis of specific flavonoids. In this study, we report on a chromosome-level S. baicalensis genome assembled to nine chromosomes (376.81M) using PacBio, HiSeq XTen, and Hi-C assisted assembly. The assembly ratio was 99.22%, the contig N50 was 1.80 million bases, and the scaffold N50 was 40.57 million bases, with 31896 genes being annotated. Comparative genome analysis revealed that S. baicalensis and Salvia miltiorrhiza belonged to the same branch, and diverged 36.3 million years ago. Other typically correlated species were Boea hygrometrica and Sesamum indicum. We investigated the structural genes involved in flavonoid synthesis in combination with transcriptome sequencing analysis for different tissues (roots, stems, flowers, leaves) of purple, pink, and white flowers. The results revealed that S.baiF6H is involved in the accumulation of baicalein and was significantly increased in both purple roots vs. pink roots and white roots vs. pink roots. S.baiMYB gene family expression pattern analysis and co-expression network analysis revealed that S.baiMYB transcription factors primarily regulated the production of flavonoids in S. baicalensis. S.baiMYB serves as a major factor regulating flavonoid synthesis in the roots, where yeast one-hybrid assays revealed that these transcription factors could bind to the promoter regions of structural genes to control the accumulation of flavonoids. Genome and transcriptome sequencing, co-expression analysis, and yeast one-hybrid experiments provided valuable genetic resources for understanding flavonoid biosynthesis in S. baicalensis. These findings contribute to a better understanding of the accumulation of metabolites in Lamiaceae.

SmMYB4 Is a R2R3-MYB Transcriptional Repressor Regulating the Biosynthesis of Phenolic Acids and Tanshinones in Salvia miltiorrhiza.

Salvia miltiorrhiza Bunge is one of the most famous traditional Chinese medicinal plants. The two most important classes of pharmaceutically relevant compounds in S. miltiorrhiza are phenolic acids and tanshinones. The MYB family of transcription factors may efficiently regulate the secondary metabolism in plants. In this study, a subgroup 4 R2R3MYB transcription factor gene, SmMYB4, was isolated from S. miltiorrhiza and functionally characterized using overexpression and a RNAi-mediated silencing. We achieved a total of six overexpressions and eight RNAi transgenic lines from the Agrobacterium leaf disc method. The content of the total phenolics, rosmarinic acid, and salvianolic acid B markedly decreased in the SmMYB4-overexpressing lines but increased in the SmMYB4-RNAi lines. The content of the total tanshinones, cryptotanshinone, and tanshinone IIA decreased in the SmMYB4-overexpressing transgenic lines but increased in the SmMYB4-RNAi lines. A gene expression analysis demonstrated that SmMYB4 negatively regulated the transcription of the critical enzyme genes involved in the phenolic acid and tanshinone biosynthesis. The genetic control of this transcriptional repressor may be used to improve the content of these bioactive compounds in the cultivated S. miltiorrhiza.

Genome-Wide Identification and Expression Patterns of the SWEET Gene Family in Bletilla striata and its Responses to Low Temperature and Oxidative Stress.

SWEETs (sugars will eventually be exported transporters), a well-known class of sugar transporters, are involved in plant growth and development, sugar transport, biotic and abiotic stresses, etc. However, to date, there have been few investigations of SWEETs in Orchidaceae. In this study, 23 SWEET genes were identified in Bletilla striata for the first time, with an MtN3/saliva conserved domain, and were divided into four subgroups by phylogenetic tree. The same subfamily members had similar gene structures and motifs. Multiple cis-elements related to sugar and environmental stresses were found in the promoter region. Further, 21 genes were localized on 11 chromosomes and 2 paralogous pairs were found via intraspecific collinearity analysis. Expression profiling results showed that BsSWEETs were tissue-specific. It also revealed that BsSWEET10 and BsSWEET18 were responsive to low temperature and oxidative stresses. In addition, subcellular localization study indicated that BsSWEET15 and BsSWEET16 were localized in the cell membrane. This study provided important clues for the in-depth elucidation of the sugar transport mechanism of BsSWEET genes and their functional roles in response to abiotic stresses.

Comprehensive functional analysis of the PYL-PP2C-SnRK2s family in Bletilla striata reveals that BsPP2C22 and BsPP2C38 interact with BsPYLs and BsSnRK2s in response to multiple abiotic stresses.

As the core regulation network for the abscisic acid (ABA) signaling pathway, the PYL-PP2C-SnRK2s family commonly exists in many species. For this study, a total of 9 BsPYLs, 66 BsPP2Cs, and 7 BsSnRK2s genes were identified based on the genomic databases of Bletilla striata, which were classified into 3, 10, and 3 subgroups, respectively. Basic bioinformatics analysis completed, including the physicochemical properties of proteins, gene structures, protein motifs and conserved domains. Multiple cis-acting elements related to stress responses and plant growth were found in promoter regions. Further, 73 genes were localized on 16 pseudochromosomes and 29 pairs of paralogous genes were found via intraspecific collinearity analysis. Furthermore, tissue-specific expression was found in different tissues and germination stages. There were two BsPYLs, 10 BsPP2Cs, and four BsSnRK2 genes that exhibited a difference in response to multiple abiotic stresses. Moreover, subcellular localization analysis revealed six important proteins BsPP2C22, BsPP2C38, BsPP2C64, BsPYL2, BsPYL8, and BsSnRK2.4 which were localized in the nucleus and plasma membrane. Finally, yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays suggested that BsPP2C22 and BsPP2C38 could interact with multiple BsPYLs and BsSnRK2s proteins. This study systematically reported on the identification and characterization of the PYL-PP2C-SnRK2s family in B. striata, which provided a conceptual basis for deep insights into the functionality of ABA core signal pathways in Orchidaceae.

Systematic Analysis and Functional Characterization of R2R3-MYB Genes in Scutellaria baicalensis Georgi.

R2R3-MYB transcription factors participate in multiple critical biological processes, particularly as relates to the regulation of secondary metabolites. The dried root of Scutellaria baicalensis Georgi is a traditional Chinese medicine and possesses various bioactive attributes including anti-inflammation, anti-HIV, and anti-COVID-19 properties due to its flavonoids. In the current study, a total of 95 R2R3-MYB genes were identified in S. baicalensis and classified into 34 subgroups, as supported by similar exon-intron structures and conserved motifs. Among them, 93 R2R3-SbMYBs were mapped onto nine chromosomes. Collinear analysis revealed that segmental duplications were primarily responsible for driving the evolution and expansion of the R2R3-SbMYB gene family. Synteny analyses showed that the ortholog numbers of the R2R3-MYB genes between S. baicalensis and other dicotyledons had a higher proportion compared to that which is found from the monocotyledons. RNA-seq data indicated that the expression patterns of R2R3-SbMYBs in different tissues were different. Quantitative reverse transcriptase-PCR (qRT-PCR) analysis showed that 36 R2R3-SbMYBs from different subgroups exhibited specific expression profiles under various conditions, including hormone stimuli treatments (methyl jasmonate and abscisic acid) and abiotic stresses (drought and cold shock treatments). Further investigation revealed that SbMYB18/32/46/60/70/74 localized in the nucleus, and SbMYB18/32/60/70 possessed transcriptional activation activity, implying their potential roles in the regulatory mechanisms of various biological processes. This study provides a comprehensive understanding of the R2R3-SbMYBs gene family and lays the foundation for further investigation of their biological function.

Identification and Characterization of Jasmonic Acid Biosynthetic Genes in Salvia miltiorrhiza Bunge.

Jasmonic acid (JA) is a vital plant hormone that performs a variety of critical functions for plants. Salvia miltiorrhiza Bunge (S. miltiorrhiza), also known as Danshen, is a renowned traditional Chinese medicinal herb. However, no thorough and systematic analysis of JA biosynthesis genes in S. miltiorrhiza exists. Through genome-wide prediction and molecular cloning, 23 candidate genes related to JA biosynthesis were identified in S. miltiorrhiza. These genes belong to four families that encode lipoxygenase (LOX), allene oxide synthase (AOS), allene oxide cyclase (AOC), and 12-OPDA reductase3 (OPR3). It was discovered that the candidate genes for JA synthesis of S. miltiorrhiza were distinct and conserved, in contrast to related genes in other plants, by evaluating their genetic structures, protein characteristics, and phylogenetic trees. These genes displayed tissue-specific expression patterns concerning to methyl jasmonate (MeJA) and wound tests. Overall, the results of this study provide valuable information for elucidating the JA biosynthesis pathway in S. miltiorrhiza by comprehensive and methodical examination.

Structural characterization and antioxidant activity of Polygonatum sibiricum polysaccharides.

Polysaccharide is one of the main active components of Polygonatum sibiricum. For this study, P. sibiricum polysaccharides (PSP) were obtained through purification using DEAE-Cellulose52 and Sephacryl G-150 column chromatography. The obtained samples were named PSP1, PSP2 and PSP3. The PSP1 sample was found to have the highest content and the best solubility, and a subsequent. So, its structure and characterization were analyzed. The main sugar residue linkages were found to be â†’ 1)-ß-D-Fruf-(2 â†’ 1)-ß-D-Fruf-(2 â†’ 1), 1 â†’ -ß-D-Fruf-(2 â†’ 6)α-D-Glcp (1→, →4)-ß-D-Manp-(1 â†’ 4)-ß-D-Manp-(1→ and →6)-ß-D-Glcp-(1 â†’ 4)-ß-D-Manp-(1→ link existed. Branch chain analysis indicated →1,6)-ß-D-Fruf-(2→, ß-D-Fruf-(2→, →1,6)-ß-D-Fruf-(2→, →6)-ß-D- Fruf-(2→ link existed, and the link site was at position C-6. In vitro antioxidant activity tests showed that PSP1 had a certain scavenging effect on DPPH, hydroxyl radical, superoxide anion radical and a particular effect on the chelating ability of ferrous. This suggested that P. sibiricum polysaccharides may be a potential antioxidant.

Correction: Glycyrrhizic acid promotes neural repair by directly driving functional remyelination.

Correction for 'Glycyrrhizic acid promotes neural repair by directly driving functional remyelination' by Jing Tian et al., Food Funct., 2020, 11, 992-1005, https://doi.org/10.1039/C9FO01459D.

Genome-Wide Identification and Characterization of the WRKY Gene Family in Scutellaria baicalensis Georgi under Diverse Abiotic Stress.

The WRKY gene family is an important inducible regulatory factor in plants, which has been extensively studied in many model plants. It has progressively become the focus of investigation for the secondary metabolites of medicinal plants. Currently, there is no systematic analysis of the WRKY gene family in Scutellaria baicalensis Georgi. For this study, a systematic and comprehensive bioinformatics analysis of the WRKY gene family was conducted based on the genomic data of S. baicalensis. A total of 77 WRKY members were identified and 75 were mapped onto nine chromosomes, respectively. Their encoded WRKY proteins could be classified into three subfamilies: Group I, Group II (II-a, II-b, II-c, II-d, II-e), and Group III, based on the characteristics of the amino acid sequences of the WRKY domain and genetic structure. Syntenic analysis revealed that there were 35 pairs of repetitive fragments. Furthermore, the transcriptome data of roots, stems, leaves, and flowers showed that the spatial expression profiles of WRKYs were different. qRT-PCR analysis revealed that 11 stress-related WRKYs exhibited specific expression patterns under diverse treatments. In addition, sub cellular localization analysis indicated that SbWRKY26 and SbWRKY41 were localized in nucleus. This study is the first to report the identification and characterization of the WRKY gene family in S. baicalensis, which is valuable for the further exploration of the biological function of SbWRKYs. It also provides valuable bioinformatics data for S. baicalensis and provides a reference for assessing the medicinal properties of the genus.

Metabolomics Study of Different Germplasm Resources for Three Polygonatum Species Using UPLC-Q-TOF-MS/MS.

Rhizomes of the Polygonatum species are well-known in traditional Chinese medicine. The 2020 edition of Chinese Pharmacopoeia includes three different species that possess different pharmacological effects. Due to the lack of standardized discriminant compounds there has often been inadvertently incorrect prescriptions given for these medicines, resulting in serious consequences. Therefore, it is critical to accurately distinguish these herbal Polygonatum species. For this study, UPLC-Q-TOF-MS/MS based metabolomics was employed for the first time to discriminate between three Polygonatum species. Partial least squares discriminant analysis (PLS-DA) models were utilized to select the potential candidate discriminant compounds, after which MS/MS fragmentation patterns were used to identify them. Meanwhile, metabolic correlations were identified using the R language package corrplot, and the distribution of various metabolites was analyzed by box plot and the Z-score graph. As a result, we found that adenosine, sucrose, and pyroglutamic acid were suitable for the identification of different Polygonatum species. In conclusion, this study articulates how various herbal Polygonatum species might be more accurately and efficiently distinguished.

Screening of Bletilla striata, Bletilla ochracea and Oreorchis foliosa differential metabolites based on metabolomics.

As a representative medicinal plant in the Orchidaceae, Bletilla striata plays a variety of pharmacological roles in the clinic. However, the emergence of counterfeit species is affecting the basic medicinal materials source identification process, for which Bletilla ochracea and Oreorchis foliosa of the Orchidaceae are two representative species. For this study, 13 representative B. striata samples, three B. ochracea samples and three O. foliosa samples were selected for the systematic determination of polysaccharide yields and monosaccharide composition, and further detection of secondary metabolites by HPLC-MS. The results revealed that there was a significant difference in the yields of polysaccharides between B. striata and B. ochracea (p = 0.006). Although the polysaccharides of both species were composed of glucose and mannose, the molar ratio of the two monosaccharides was different, suggesting that the structures of the polysaccharides were different. The metabolomics results showed that there were no differences in the types of metabolites between B. striata and B. ochracea; however, there were differences in the contents of these metabolites. Although there was no significant difference in the polysaccharide yields of B. striata and O. foliosa (p = 0.074) and the monosaccharide composition was the same (glucose and mannose), many different metabolites were screened out between them: six compounds such as C36 H34 O11 existed only in B. striata, while substance C39 H54 O22 was unique to O. foliosa. Therefore, based on the analysis of the polysaccharide content and monosaccharide composition, combined with phase metabolomics research, a preliminary distinction between B. striata, B. ochracea and O. foliosa was achieved.