DNA methylation regulates biosynthesis of tanshinones and phenolic acids during growth of Salvia miltiorrhiza.

DNA methylation plays a crucial role in the regulation of plant growth and the biosynthesis of secondary metabolites. Danshen (Salvia miltiorrhiza) is a valuable Chinese herbal medicine commonly used to treat cardiovascular diseases; its active ingredients are tanshinones and phenolic acids, which primarily accumulate in roots. Here, we conducted a targeted metabolic analysis of S. miltiorrhiza roots at 3 distinct growth stages: 40 d old (r40), 60 d old (r60), and 90 d old (r90). The contents of tanshinones (cryptotanshinone, tanshinone I, tanshinone IIA, and rosmariquinone) and phenolic acids (rosmarinic acid and salvianolic acid B) gradually increased during plant development. Whole-genome bisulfite sequencing and transcriptome sequencing of roots at the 3 growth stages revealed an increased level of DNA methylation in the CHH context (H represents A, T, or C) context at r90 compared with r40 and r60. Increased DNA methylation levels were associated with elevated expression of various genes linked to epigenetic regulations, including CHROMOMETHYLASE2 (SmCMT2), Decrease in DNA Methylation 1 (SmDDM1), Argonaute 4 (SmAGO4), and DOMAINS REARRANGED METHYLTRANSFERASE 1 (SmDRM1). Moreover, expression levels of many genes involved in tanshinone and salvianolic acid biosynthesis, such as copalyldiphosphate synthase 5 (SmCPS5), cytochrome P450-related enzyme (SmCYP71D464), geranylgeranyl diphosphate synthase (SmGGPPS1), geranyl diphosphate synthase (SmGPPS), hydroxyphenylpyruvate reductase (SmHPPR), and hydroxyphenylpyruvate dioxygenase (SmHPPD), were altered owing to hyper-methylation, indicating that DNA methylation plays an important role in regulating tanshinone and phenolic acid accumulation. Our data shed light on the epigenetic regulation of root growth and the biosynthesis of active ingredients in S. miltiorrhiza, providing crucial clues for further improvement of active compound production via molecular breeding in S. miltiorrhiza.

Endophytic fungus Penicillium steckii DF33 promoted tanshinones biosynthesis in Salvia miltiorrhiza by regulating the expression of CYP450 genes.

Salvia miltiorrhiza, a prominent traditional Chinese medicinal resource, has been extensively employed in the management of cardiovascular and cerebrovascular ailments. Ensuring the consistency of S. miltiorrhiza raw materials revolves around the imperative task of maintaining stable tanshinones content and composition. An effective approach in this regard involves the utilization of endophytic fungi as inducers. Within this context, our study spotlights an endophytic fungus, Penicillium steckii DF33, isolated from the roots of S. miltiorrhiza. Remarkably, this fungus has demonstrated a significant capacity to boost the biosynthesis and accumulation of tanshinones. The primary objective of this investigation is to elucidate the underlying regulatory mechanism by which DF33 enhances and regulates the biosynthesis and accumulation of tanshinones. This is achieved through its influence on the differential expression of crucial CYP450 genes within the S. miltiorrhiza hairy roots system. The results revealed that the DF33 elicitor not only promotes the growth of hairy roots but also enhances the accumulation of tanshinones. Notably, the content of cryptotanshinone was reached 1.6452 ± 0.0925 mg g-1, a fourfold increase compared to the control group. Our qRT-PCR results further demonstrate that the DF33 elicitor significantly up-regulates the expression of most key enzyme genes (GGPPS, CPS1, KSL1, CYP76AH1, CYP76AH3, CYP76AK1, CYP71D411) involved in the tanshinone biosynthesis pathway. This effect is particularly pronounced in certain critical CYP450 genes and Tanshinone ⅡA synthase (SmTⅡAS), with their expression levels peaking at 7 days or 14 days, respectively. In summary, endophytic P. steckii DF33 primarily enhances tanshinone biosynthesis by elevating the expression levels of pivotal enzyme genes associated with the modification and transformation stages within the tanshinone biosynthesis pathway. These findings underscore the potential of employing plant probiotics, specifically endophytic and root-associated microbes, to facilitate the biosynthesis and transformation of vital constituents in medicinal plants, and this approach holds promise for enhancing the quality of traditional Chinese medicinal materials.

Evolution and chemical diversity of the volatile compounds in Salvia species.

INTRODUCTION: The plant essential oils are composed of volatile compounds and have significant value in preventing and treating neurological diseases, anxiety, depression, among others. The genus Salvia has been shown to be an important medicinal resource, especially the aerial parts of genus Salvia, which are rich in volatile compounds; however, the chemical diversity and distribution patterns of volatile compounds in Salvia species are still unknown. OBJECTIVE: The work is performed to analyse the chemical diversity and distribution patterns of volatile compounds in genus Salvia. METHODS: The genomic single nucleotide polymorphisms (SNPs) combined with gas chromatography-mass spectrometry (GC-MS) were used to explore the evolution and chemical diversity of Salvia volatile compounds. Initially, the genetic relationship of genus Salvia was revealed by phylogenetic tree that was constructed based on SNPs. And then, GC-MS was applied to explore the chemical diversity of volatile compounds. RESULTS: The results indicated that the volatile compounds were mainly monoterpenoids, sesquiterpenoids, and aliphatic compounds. The genomic SNPs divided species involved in this work into four branches. The volatile compounds in the first and second branches were mainly sesquiterpenoids and monoterpenoids, respectively. Species in the third branch contained more aliphatic compounds and sesquiterpenoids. And those in the fourth branch were also rich in monoterpenoids but had relatively simple chemical compositions. CONCLUSION: This study offered new insights into the phylogenetic relationships besides chemistry diversity and distribution pattern of volatile compounds of genus Salvia, providing theoretical guidance for the investigations and development of secondary metabolites.

Global proteome and lysine succinylation analyses provide insights into the secondary metabolism in Salvia miltiorrhiza.

Danshen, belongs to the Lamiaceae family, and its scientific name is Salvia miltiorrhiza Bunge. It is a valuable medicinal plant to prevent and treat cardiovascular and cerebrovascular diseases. Lysine succinylation, a widespread modification found in various organisms, plays a critical role in regulating secondary metabolism in plants. The hairy roots of Salvia miltiorrhiza were subject to proteomic analysis to identify lysine succinylation sites using affinity purification and HPLC-MS/MS in this investigation. Our findings reveal 566 lysine succinylation sites in 348 protein sequences. We observed 110 succinylated proteins related to secondary metabolism, totaling 210 modification sites. Our analysis identified 53 types of enzymes among the succinylated proteins, including phenylalanine ammonia-lyase (PAL) and aldehyde dehydrogenase (ALDH). PAL, a crucial enzyme involved in the biosynthesis of rosmarinic acid and flavonoids, displayed succinylation at two sites. ALDH, which participates in the phenylpropane metabolic pathway, was succinylated at 8 eight sites. These observations suggest that lysine succinylation may play a vital role in regulating the production of secondary metabolites in Salvia miltiorrhiza. Our study may provide valuable insights for further investigation on plant succinylation, specifically as a reference point. SIGNIFICANCE: Salvia miltiorrhiza Bunge is a valuable medicinal plant that prevents and treats cardiovascular and cerebrovascular diseases. Lysine succinylation plays a critical role in regulating secondary metabolism in plants. The hairy roots of Salvia miltiorrhiza were subject to proteomic analysis to identify lysine succinylation sites using affinity purification and HPLC-MS/MS in this investigation. These observations suggest that lysine succinylation may act as a vital role in regulating the production of secondary metabolites in Salvia miltiorrhiza. Our study may provide valuable insights for further investigation on succinylation in plants, specifically as a reference point.

Functional Study and Efficient Catalytic Element Mining of CYP76AHs in Salvia Plants.

Salvia is a large genus with hundreds of species used in traditional Chinese medicine. Tanshinones are a highly representative class of exclusive compounds found in the Salvia genus that exhibit significant biological activity. Tanshinone components have been identified in 16 Salvia species. The CYP76AH subfamily (P450) is crucial for the synthesis of tanshinone due to its catalytic generation of polyhydroxy structures. In this study, a total of 420 CYP76AH genes were obtained, and phylogenetic analysis showed their clear clustering relationships. Fifteen CYP76AH genes from 10 Salvia species were cloned and studied from the perspectives of evolution and catalytic efficiency. Three CYP76AHs with significantly improved catalytic efficiency compared to SmCYP76AH3 were identified, providing efficient catalytic elements for the synthetic biological production of tanshinones. A structure-function relationship study revealed several conserved residues that might be related to the function of CYP76AHs and provided a new mutation direction for the study of the directed evolution of plant P450.

The complete chloroplast genome sequence of Salvia chienii E.Peter, 1936 (Lamiaceae).

Salvia chienii E.Peter is a medicinal herb mainly distributed in Huangshan Mountain of Anhui province, China. In this study, the first complete chloroplast genome of S. chienii was sequenced and assembled. The genome length was 151,530 bp and encoded 143 genes (91 protein-coding genes, eight rRNA genes, and 37 tRNA genes). The phylogenomic analysis showed that S. chienii was closely related to S. miltiorrhiza. Further evolutionary studies of the genus Salvia could benefit from the complete chloroplast genome of S. chienii present in this study.

Antioxidative and Cytoprotective Effects of Ganoderma applanatum and Fomitopsis pinicola in PC12 Adrenal Phaeochromocytoma Cells.

Considering the impact of oxidative stress on the development of many diseases, together with the role of natural antioxidants in maintaining physiological balance in humans, medicinal mushrooms are potential sources of bioactive compounds against many diseases. In the present work, in vitro evaluation of the biological activities of the alcoholic extracts of two wild tree mushrooms, namely, Ganoderma applanatum and Fomitopsis pinicola, has been performed. Extraction of G. applanatum (GAE) and F. pinicola (FPE) was conducted with 60% ethanol and 100% ethanol sequentially. UPLC-MS/MS identification was conducted on the two mushrooms extracts. A total of 15 substances were identified in GAE, including 3 spiro meroterpenoids and 12 triterpenoids; a total of 14 chemical constituents were iden¬tified in FPE, including 8 triterpenoids, 4 triterpene glycosides, 1 lanosterol, and 1 lanostanoid. The resulting extracts were examined for their in vitro antioxidative and cytoprotective effects against AAPH-induced oxidative damage. Our results demonstrated that both extracts have potent antioxidative activities, when GAE was 0.2 mg/mL, the clearance rates of DPPH and ABTS have reached 93.34% and 99.93%, respectively. When FPE was 1.4 mg/mL and 0.6 mg/mL, the scavenging rates of DPPH and ABTS have reached 91.76% and 100%, respectively. Both the alcoholic extracts of G. applanatum and F. pinicola were able to protect the AAPH-induced damage and could effectively inhibit cell aging via ß-galactosidase (SA ß-gal) staining activity test and scanning electron microscopy analysis.

[Three-dimensional multi-component quality evaluation of Chinese medicine based on proportion consistency of active components: a study of Salvia miltiorrhiza].

To reveal the law of the proportion consistency of the active components in Chinese medicine and explore a new way to evaluate the quality of Chinese medicine, the present study investigated the content of tanshinone Ⅱ_A, cryptotanshinone, tanshinone Ⅰ, salvianolic acid B, rosmarinic acid, caffeic acid, and lithospermic acid in 895 samples of Salvia miltiorrhiza from 87 literature articles. The samples with salvianolic acid B and tanshinones(total content of tanshinone Ⅱ_A, tanshinone Ⅰ, and cryptotanshinone) meeting the requirements of Chinese Pharmacopoeia were analyzed for proportion consistency of components, and the proportion distribution of components was compared. The results showed that the proportions in and between tanshinones and salvianolic acids were stable. The content ratios of cryptotanshinone to tanshinone Ⅱ_A, rosmarinic acid to salvianolic acid B, and salvianolic acid B to tanshinone Ⅱ_A fluctuated from 0.1 to 1.7, from 0.02 to 0.14, and from 10 to 60, respectively. It indicated that the content proportions of different components were not fixed, but fluctuated in a certain range. The fluctuation range of components in the same group was small, but that in different groups was large. The content proportions of active components were stable for Chinese medicinal materials with fixed varieties or origins. The samples whose content proportions were out of the fluctuation ranges were generally unqualified medicinal materials. We proposed a "three-dimensional multi-component" quality evaluation model of Chinese medicine based on the above findings. Specifically, "three-dimensional" means to accurately evaluate the quality of Chinese medicine from varieties, proportions, and content of active components, and "multi-component" means to highlight the information of multiple components in Chinese medicine, especially the quality markers and equivalent component groups. The proportion of components in Chinese medicine can be used as an important index for the quality evaluation of Chinese medicine. The proportions of active components are stable in Chinese medicinal materials with fixed varieties or places of origin.

Endophytic fungus Cladosporium tenuissimum DF11, an efficient inducer of tanshinone biosynthesis in Salvia miltiorrhiza roots.

Salvia miltiorrhiza is a traditional medicinal plant mainly used for cardiovascular and cerebrovascular disease treatment. Tanshinones are the main bioactive constituents of S. miltiorrhiza, which mainly accumulate around its root periderm tissue. Endophytic fungi are important bioelicitors or probiotics that can promote the accumulation of secondary metabolites and sustainable cultivation of medicinal plants. Among them, endophytic Cladosporium spp., possessing a variety of biotransformation and metabolic abilities, is an ideal elicitor source. Here, we used a gnotobiotic system to investigate the effects of the endophytic fungus Cladosporium tenuissimum DF11 on tanshinone biosynthesis in S. miltiorrhiza roots. The results showed that C. tenuissimum DF11 mainly colonizes the intercellular space of the root tissues and promotes tanshinone biosynthesis and accumulation in S. miltiorrhiza roots by upregulating the expression of the genes encoding for key enzymes HMGR, DXS, DXR, GGPPS, CPS, KSL and CYP76AH1 of the tanshinone biosynthesis pathway. The expression levels of almost all genes encoding for key enzymes reached the response peak in the first or second week after DF11 colonization. Taken together, the endophytic fungus C. tenuissimum DF11 could promote secondary metabolite accumulation in S. miltiorrhiza roots. These results indicate that DF11 will be a potential biofertilizer fungus to regulate and stabilize the quality of cultivated S. miltiorrhiza medicinal materials.

Effects of Light on Secondary Metabolite Biosynthesis in Medicinal Plants.

Secondary metabolites (SMs) found in medicinal plants are one of main sources of drugs, cosmetics, and health products. With the increase in demand for these bioactive compounds, improving the content and yield of SMs in medicinal plants has become increasingly important. The content and distribution of SMs in medicinal plants are closely related to environmental factors, especially light. In recent years, artificial light sources have been used in controlled environments for the production and conservation of medicinal germplasm. Therefore, it is essential to elucidate how light affects the accumulation of SMs in different plant species. Here, we systematically summarize recent advances in our understanding of the regulatory roles of light quality, light intensity, and photoperiod in the biosynthesis of three main types of SMs (polyphenols, alkaloids, and terpenoids), and the underlying mechanisms. This article provides a detailed overview of the role of light signaling pathways in SM biosynthesis, which will further promote the application of artificial light sources in medicinal plant production.

SmKFB5 protein regulates phenolic acid biosynthesis by controlling the degradation of phenylalanine ammonia-lyase in Salvia miltiorrhiza.

Phenolic acids are the major secondary metabolites and significant bioactive constituents of the medicinal plant Salvia miltiorrhiza. Many enzyme-encoding genes and transcription factors involved in the biosynthesis of phenolic acids have been identified, but the underlying post-translational regulatory mechanisms are poorly understood. Here, we demonstrate that the S. miltiorrhiza Kelch repeat F-box protein SmKFB5 physically interacts with three phenylalanine ammonia-lyase (PAL) isozymes and mediates their proteolytic turnover via the ubiquitin-26S proteasome pathway. Disturbing the expression of SmKFB5 reciprocally affected the abundance of SmPAL protein and the accumulation of phenolic acids, suggesting that SmKFB5 is a post-translational regulator responsible for the turnover of PAL and negatively controlling phenolic acids. Furthermore, we discovered that treatment of the hairy root of S. miltiorrhiza with methyl jasmonate suppressed the expression of SmKFB5 while inducing the transcription of SmPAL1 and SmPAL3. These data suggested that methyl jasmonate consolidated both transcriptional and post-translational regulation mechanisms to enhance phenolic acid biosynthesis. Taken together, our results provide insights into the molecular mechanisms by which SmKFB5 mediates the regulation of phenolic acid biosynthesis by jasmonic acid, and suggest valuable targets for plant breeders in tailoring new cultivars.

Endophytic fungus Mucor circinelloides DF20 promote tanshinone biosynthesis and accumulation in Salvia miltiorrhiza root.

As a traditional Chinese medicine, Salvia miltiorrhiza rhizome is mainly used to treat cardiovascular diseases. Symbiosis of endophytic fungi with their host plants, is an effectively regulatory means to promote the growth and secondary metabolism of medicinal plants. Here, an endophytic fungus Mucor circinelloides DF20 was co-cultivated with the sterile seedlings of S. miltiorrhiza, to clarify the promoting mechanism on tanshinone biosynthesis and accumulation in S. miltiorrhiza root. The assay of promoting-growth activities in vitro showed that DF20 have the ability to produce IAA and siderophores. DF20 could significantly promote the biosynthesis and accumulation of tanshinones in the root of S. miltiorrhiza, especially the content of tanshinone ⅡA, reaching 4.630 ± 0.342 mg/g after 56 days of DF20 treatment, which is 22-fold of the control group. The result also showed that the hyphae of M. circunelloides DF20 mainly colonized in the root tissue interspace of S. miltiorrhiza, and a small amount of hyphae were located inside the cells. The results of florescent real-time quantitative RT-PCR showed that DF20 colonization significantly increase the expression level of some key enzyme genes (DXS, DXR, HMGR, GGPPS) in tanshinone biosynthesis pathway, but the regulatory effect mainly occurred in the early stage of co-culture, while the expression level decreased in different degrees in the later stage. In conclusion, the endophytic fungus M. circunelloides DF20 can form an interaction relationship with its host, then to promote the biosynthesis and accumulation of tanshinones in root by upregulating the key enzyme genes expression levels of the biosynthesis pathway.

Current advances in environmental stimuli regulating the glycyrrhizic acid biosynthesis pathway.

Glycyrrhizic acid, the main active ingredient of licorice, has good antibacterial, anti-tumor, anti-viral, anti-inflammatory, and immunostimulatory activities. However, the content of glycyrrhizic acid fluctuates greatly in different licorice cultivars, and production depends on plant sources, which greatly limits its development and applications. Therefore, increasing glycyrrhizic acid content has become a research priority. In recent years, regulation of the glycyrrhizic acid biosynthesis pathway has been analyzed, the downstream synthesis pathway in licorice has been fully investigated, some key genes have been cloned, polymorphisms have been studied, and the content of glycyrrhizic acid was shown to be regulated by environmental stimuli. This work has provided a basis for studying the regulation mechanism of the glycyrrhizic acid synthesis pathway. This review summarizes and discusses relevant research to provide a current understanding of the glycyrrhizic acid synthesis pathway and its regulation in licorice.

[Effects of different carbon sources on growth and active component contents in Salvia miltiorrhiza and S. castanea f. tomentosa hairy roots].

Salvia miltiorrhiza(Sm) and Salvia castanea f. tomentosa(Sc) hairy roots were used as experimental materials to study the effects of six different carbon sources, galactose, fructose, lactose, glucose, arabinose and sucrose(control), on fresh weight, dry weight, contents and yields of salvianolic acids and tanshinones. The results showed that galactose was most beneficial to the growth of two kinds of hairy roots, while lactose and arabinose were not conducive to their growth. As for Sm hairy roots, fructose significantly promoted the accumulation of salvianolic acid B, and the content increased by 5.801 times and 10.151 times compared with the control group, respectively. Glucose significantly promoted the accumulation of salvianolic acids. The content and yield of rosmarinic acid were 7.674 times and 9.260 times of that of the control group, and the content and yield of salvianolic acid B were 5.532 times and 6.675 times of the control group. For the hairy roots of Sc, galactose significantly increased the content and yield of rosmarinic acid, reaching 7.820 times and 9.944 times of the control group, respectively. Fructose promoted the increase of the content and yield of cryptotanshinone, reaching 9.242 times and 6.609 times of the control group, respectively. The study confirmed the optimal carbon source for the hairy root culture of Sm and Sc, and provided theoretical guidance for large-scale production of Sm drug-derived components and the utilization of Sc.

An attempt to establish an Agrobacterium-mediated transient expression system in medicinal plants.

Genetic transformation has always been an important method for studying medical plant secondary metabolic regulation, among which stable transformation has a good reproducibility. However, it was time-consuming to obtain a stable transformed hairy root or transgenic plants, which was difficult to satisfy the great demand of researches on medical plant secondary metabolism-related genes. Moreover, Agrobacterium tumefaciens-mediated transient transformation has been extensively applied in studies of functional genes because of its simpleness, low cost, and short period. However, presently, researches on medical plant functional genes commonly used stable genetic transformation and some high-cost and high-difficulty transient transformation methods, such as gene gun and protoplast transformation. Thus, in this study, we selected the seedlings of Nicotiana benthamiana, Salvia miltiorrhiza, and Prunella vulgaris as the experimental material, with the methods of Agrobacterium tumefaciens injection, fast Agrobacterium-mediated seedling transformation (FAST), and FAST and mechanical damage. The results demonstrated that the injection transient transformation system of pCAMBIA1301 vector mediated by A. tumefaciens and the transient transformation of seedling system were not established in S. miltiorrhiza. In addition, the instantaneous transformation system of N. benthamiana and P. vulgaris seedlings was basically set up by FAST method. Besides, using the method of FAST and mechanical damage, the transient genetic transformation system of P. vulgaris seedlings was established for the first time. A. tumefaciens-mediated transient transformation of seedlings with pEAQ vectors provided an effective way and reference for the further study of functional genes of the medicinal plants N. benthamiana and P. vulgaris.

Quantitative Determination and Validation of Four Ketones in Salvia miltiorrhiza Bunge Using Quantitative Proton Nuclear Magnetic Resonance Spectroscopy.

Salvia mltiorrhiza Bunge (SMB) is native to China, whose dried root has been used as medicine. A few chromatographic- or spectrometric-based methods have already been used to analyze the lipid-soluble components in SMB. However, the methodology of qNMR on the extracts of fresh SMB root has not been verified so far. The purpose of this study was to establish a fast and simple method to quantify the tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone in fresh Salvia Miltiorrhiza Bunge root without any pre-purification steps using 1H-NMR spectroscopy. The process is as follows: first, 70% methanol aqueous extracts of fresh Salvia Miltiorrhiza Bunge roots were quantitatively analyzed for tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone using 1H-NMR spectroscopy. Different internal standards were tested and the validated method was compared with HPLC. 3,4,5-trichloropyridine was chosen as the internal standard. Twelve samples of Salvia Miltiorrhiza Bunge were quantitatively analyzed by qNMR and HPLC respectively. Then, the results were analyzed by chemometric approaches. This NMR method offers a fast, stable, and accurate analysis of four ketones: tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone in fresh roots of Salvia Miltiorrhiza Bunge.

SmGRAS1 and SmGRAS2 Regulate the Biosynthesis of Tanshinones and Phenolic Acids in Salvia miltiorrhiza.

Salvia miltiorrhiza is one of the most widely used traditional Chinese medicinal plants because of its excellent performance in treating heart diseases. Tanshinones and phenolic acids are two important classes of effective metabolites, and their biosynthesis has attracted widespread interest. Here, we functionally characterized SmGRAS1 and SmGRAS2, two GRAS family transcription factors from S. miltiorrhiza. SmGRAS1/2 were highly expressed in the root periderm, where tanshinones mainly accumulated in S. miltiorrhiza. Overexpression of SmGRAS1/2 upregulated tanshinones accumulation and downregulated GA, phenolic acids contents, and root biomass. However, antisense expression of SmGRAS1/2 reduced the tanshinones accumulation and increased the GA, phenolic acids contents, and root biomass. The expression patterns of biosynthesis genes were consistent with the changes in compounds accumulation. GA treatment increased tanshinones, phenolic acids, and GA contents in the overexpression lines, and restored the root growth inhibited by overexpressing SmGRAS1/2. Subsequently, yeast one-hybrid, dual-luciferase, and electrophoretic mobility shift assays (EMSA) showed SmGRAS1 promoted tanshinones biosynthesis by directly binding to the GARE motif in the SmKSL1 promoter and activating its expression. Yeast two-hybrid assays showed SmGRAS1 interacted physically with SmGRAS2. Taken together, the results revealed that SmGRAS1/2 acted as repressors in root growth and phenolic acids biosynthesis but as positive regulators in tanshinones biosynthesis. Overall, our findings revealed the potential value of SmGRAS1/2 in genetically engineering changes in secondary metabolism.

Climatic factors control the geospatial distribution of active ingredients in Salvia miltiorrhiza Bunge in China.

Climate change profoundly influences the geospatial distribution of secondary metabolites and causes the geographical migration of plants. We planted seedlings of the same species in eighteen ecological regions along a latitudinal gradient in eastern and western China, in order to explore the regulation of multi-climatic factors on active ingredient accumulation in Salvia miltiorrhiza Bunge. The correlations between six active ingredient contents and ten climatic factors were investigated to clarify their relationships. We found that climatic factors not only regulated active ingredient contents but also markedly influenced their composition and led to a specific geospatial distribution of these active ingredients in China. The main climatic factors include the air temperature, precipitation, atmospheric vapour pressure and sunshine duration. Future warming in high-latitude regions could cause continued northward expansion of planting areas suitable for S. miltiorrhiza. The effect of extreme climatic conditions on active ingredients should not be overlooked. The findings of this study can help farmers scientifically choose suitable cultivation regions in the future. Furthermore, this study provides an innovative idea for the exploration of secondary metabolic responses to changing ecological factors in medicinal plants.

Bivariate Correlation Analysis of the Chemometric Profiles of Chinese Wild Salvia miltiorrhiza Based on UPLC-Qqq-MS and Antioxidant Activities.

To better understand the mechanisms underlying the pharmacological actions of Salvia miltiorrhiza, correlation between the chemical profiles and in vitro antioxidant activities in 50 batches of wild S. miltiorrhiza samples was analyzed. Our ultra-performance liquid chromatography-tandem mass spectrometry analysis detected twelve phenolic acids and five tanshinones and obtained various chemical profiles from different origins. In a principal component analysis (PCA) and cluster analysis, the tanshinones cryptotanshinone, tanshinone IIA and dihydrotanshinone I exhibited higher weights in PC1, whereas the phenolic acids danshensu, salvianolic acids A and B and lithospermic acid were highly loaded in PC2. All components could be optimized as markers of different locations and might be suitable for S. miltiorrhiza quality analyses. Additionally, the DPPH and ABTS assays used to comprehensively evaluate antioxidant activities indicated large variations, with mean DPPH and ABTS scavenging potencies of 32.24 and 23.39 µg/mL, respectively, among S. miltiorrhiza extract solutions. Notably, samples that exceeded the mean IC50 values had higher phenolic acid contents. A correlation analysis indicated a strong correlation between the antioxidant activities and phenolic acid contents. Caffeic acid, danshensu, rosmarinic acid, lithospermic acid and salvianolic acid B were major contributors to antioxidant activity. In conclusion, phenolic compounds were the predominant antioxidant components in the investigated plant species. These plants may be sources of potent natural antioxidants and beneficial chemopreventive agents.

Two CYP82D Enzymes Function as Flavone Hydroxylases in the Biosynthesis of Root-Specific 4'-Deoxyflavones in Scutellaria baicalensis.

Baicalein, wogonin, and their glycosides are major bioactive compounds found in the medicinal plant Scutellaria baicalensis Georgi. These flavones can induce apoptosis in a variety of cancer cell lines but have no effect on normal cells. Furthermore, they have many additional benefits for human health, such as anti-oxidant, antiviral, and liver-protective properties. Here, we report the isolation and characterization of two CYP450 enzymes, SbCYP82D1.1 and SbCYP82D2, which function as the flavone 6-hydroxylase (F6H) and flavone 8-hydroxylase (F8H), respectively, in S. baicalensis. SbCYP82D1.1 has broad substrate specificity for flavones such as chrysin and apigenin and is responsible for biosynthesis of baicalein and scutellarein in roots and aerial parts of S. baicalensis, respectively. When the expression of SbCYP82D1.1 is knocked down, baicalin and baicalein levels are reduced significantly while chrysin glycosides accumulate in hairy roots. SbCYP82D2 is an F8H with high substrate specificity, accepting only chrysin as its substrate to produce norwogonin, although minor 6-hydroxylation activity can also be detected. Phylogenetic analysis suggested that SbCYP82D2 might have evolved from SbCYP82D1.1 via gene duplication followed by neofunctionalization, whereby the ancestral F6H activity is partially retained in the derived SbCYP82D2.