Genome-wide identification of the SAUR gene family and screening for SmSAURs involved in root development in Salvia miltiorrhiza.

KEY MESSAGE: SmSAUR4, SmSAUR18, SmSAUR28, SmSAUR37, and SmSAUR38 were probably involved in the auxin-mediated root development in Salvia miltiorrhiza. Salvia miltiorrhiza is a widely utilized medicinal plant in China. Its roots and rhizomes are the main medicinal portions and are closely related to the quality of this herb. Previous studies have revealed that auxin plays pivotal roles in S. miltiorrhiza root development. Whether small auxin-up RNA genes (SAURs), which are crucial early auxin response genes, are involved in auxin-mediated root development in S. miltiorrhiza is worthy of investigation. In this study, 55 SmSAUR genes in S. miltiorrhiza were identified, and their physical and chemical properties, gene structure, cis-acting elements, and evolutionary relationships were analyzed. The expression levels of SmSAUR genes in different organs of S. miltiorrhiza were detected using RNA-seq combined with qRT‒PCR. The root development of S. miltiorrhiza seedlings was altered by the application of indole-3-acetic acid (IAA), and Pearson correlation coefficient analysis was conducted to screen SmSAURs that potentially participate in this physiological process. The diameter of primary lateral roots was positively correlated with SmSAUR4. The secondary lateral root number was positively correlated with SmSAUR18 and negatively correlated with SmSAUR4. The root length showed a positive correlation with SmSAUR28 and SmSAUR37 and a negative correlation with SmSAUR38. The fresh root biomass exhibited a positive correlation with SmSAUR38 and a negative correlation with SmSAUR28. The aforementioned SmSAURs were likely involved in auxin-mediated root development in S. miltiorrhiza. Our study provides a comprehensive overview of SmSAURs and provides the groundwork for elucidating the molecular mechanism underlying root morphogenesis in this species.

Metabolomic and transcriptomic analyses highlight metabolic regulatory networks of Salvia miltiorrhiza in response to replant disease.

BACKGROUND: Salvia miltiorrhiza, a well-known traditional Chinese medicine, frequently suffers from replant diseases that adversely affect its quality and yield. To elucidate S. miltiorrhiza's metabolic adaptations to replant disease, we analyzed its metabolome and transcriptome, comparing normal and replant diseased plants for the first time. RESULTS: We identified 1,269 metabolites, 257 of which were differentially accumulated metabolites, and identified 217 differentially expressed genes. Integrated transcriptomic and metabolomic analyses revealed a significant up-regulation and co-expression of metabolites and genes associated with plant hormone signal transduction and flavonoid biosynthesis pathways in replant diseases. Within plant hormone signal transduction pathway, plants afflicted with replant disease markedly accumulated indole-3-acetic acid and abscisic acid, correlating with high expression of their biosynthesis-related genes (SmAmidase, SmALDH, SmNCED, and SmAAOX3). Simultaneously, changes in hormone concentrations activated plant hormone signal transduction pathways. Moreover, under replant disease, metabolites in the local flavonoid metabolite biosynthetic pathway were significantly accumulated, consistent with the up-regulated gene (SmHTC1 and SmHTC2). The qRT-PCR analysis largely aligned with the transcriptomic results, confirming the trends in gene expression. Moreover, we identified 10 transcription factors co-expressed with differentially accumulated metabolites. CONCLUSIONS: Overall, we revealed the key genes and metabolites of S. miltiorrhiza under replant disease, establishing a robust foundation for future inquiries into the molecular responses to combat replant stress.

Genomic analysis of PIN-FORMED genes reveals the roles of SmPIN3 in root architecture development in Salvia miltiorrhiza.

Salvia miltiorrhiza is a widely utilized medicinal herb in China. Its roots serve as crucial raw materials for multiple drugs. The root morphology is essential for the quality of this herb, but little is known about the molecular mechanism underlying the root development in S. miltiorrhiza. Previous study reveals that the polar auxin transport is critical for lateral root development in S. miltiorrhiza. Whether the auxin efflux carriers PIN-FORMEDs (PINs) are involved in this process is worthy investigation. In this study, we identified nine SmPIN genes in S. miltiorrhiza, and their chromosome localization, physico-chemical properties, and phylogenetic relationship were analyzed. SmPINs were unevenly distributed across four chromosomes, and a variety of hormone responsive elements were detected in their promoter regions. The SmPIN proteins were divided into three branches according to the phylogenetic relationship. SmPINs with close evolutionary distance showed similar conserved motif features. The nine SmPINs showed distinct tissue-specific expression patterns and most of them were auxin-inducible genes. We generated SmPIN3 overexpression S. miltiorrhiza seedlings to investigate the function of SmPIN3 in the root development in this species. The results demonstrated that SmPIN3 regulated the root morphogenesis of S. miltiorrhiza by simultaneously affecting the lateral root development and the root anatomical structure. The root morphology, patterns of root xylem and phloem as well as the expressions of genes in the auxin signaling pathway all altered in the SmPIN3 overexpression lines. Our findings provide new insights for elucidating the regulatory roles of SmPINs in the auxin-mediated root development in S. miltiorrhiza.

Genome-Wide Identification and Functional Analysis of Salvia miltiorrhiza MicroRNAs Reveal the Negative Regulatory Role of Smi-miR159a in Phenolic Acid Biosynthesis.

MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs in plants. They play critical functions in various biological processes during plant growth and development. Salvia miltiorrhiza is a well-known traditional Chinese medicinal plant with significant medicinal, economic, and academic values. In order to elucidate the role of miRNAs in S. miltiorrhiza, six small RNA libraries from mature roots, young roots, stems, mature leaves, young leaves and flowers of S. miltiorrhiza and one degradome library from mixed tissues were constructed. A total of 184 miRNA precursors, generating 137 known and 49 novel miRNAs, were genome-widely identified. The identified miRNAs were predicted to play diversified regulatory roles in plants through regulating 891 genes. qRT-PCR and 5' RLM-RACE assays validated the negative regulatory role of smi-miR159a in SmMYB62, SmMYB78, and SmMYB80. To elucidate the function of smi-miR159a in bioactive compound biosynthesis, smi-miR159a transgenic hairy roots were generated and analyzed. The results showed that overexpression of smi-miR159a caused a significant decrease in rosmarinic acid and salvianolic acid B contents. qRT-PCR analysis showed that the targets of smi-miR159a, including SmMYB62, SmMYB78, and SmMYB80, were significantly down-regulated, accompanied by the down-regulation of SmPAL1, SmC4H1, Sm4CL1, SmTAT1, SmTAT3, SmHPPR1, SmRAS, and SmCYP98A14 genes involved in phenolic acid biosynthesis. It suggests that smi-miR159a is a significant negative regulator of phenolic acid biosynthesis in S. miltiorrhiza.

Changes in secondary metabolites contents and stress responses in Salvia miltiorrhiza via ScWRKY35 overexpression: Insights from a wild relative Salvia castanea.

Salvia castanea Diels, a close wild relative to the medicinal plant, Salvia miltiorrhiza Bunge, primarily grows in high-altitude regions. While the two species share similar active compounds, their content varies significantly. WRKY transcription factors are key proteins, which regulate plant growth, stress response, and secondary metabolism. We identified 46 ScWRKY genes in S. castanea and found that ScWRKY35 was a highly expressed gene associated with secondary metabolites accumulation. This study aimed to explore the role of ScWRKY35 gene in regulating the accumulation of secondary metabolites and its response to UV and cadmium (Cd) exposure in S. miltiorrhiza. It was found that transgenic S. miltiorrhiza hairy roots overexpressing ScWRKY35 displayed upregulated expression of genes related to phenolic acid synthesis, resulting in increased salvianolic acid B (SAB) and rosmarinic acid (RA) contents. Conversely, tanshinone pathway gene expression decreased, leading to lower tanshinone levels. Further, overexpression of ScWRKY35 upregulated Cd transport protein HMA3 in root tissues inducing Cd sequestration. In contrast, the Cd uptake gene NRAMP1 was downregulated, reducing Cd absorption. In response to UV radiation, ScWRKY35 overexpression led to an increase in the accumulation of phenolic acid and tanshinone contents, including upregulation of genes associated with salicylic acid (SA) and jasmonic acid (JA) synthesis. Altogether, these findings highlight the role of ScWRKY35 in enhancing secondary metabolites accumulation, as well as in Cd and UV stress modulation in S. miltiorrhiza, which offers a novel insight into its phytochemistry and provides a new option for the genetic improvement of the plants.

The SmMYC2-SmMYB36 complex is involved in methyl jasmonate-mediated tanshinones biosynthesis in Salvia miltiorrhiza.

The jasmonic acid (JA) signaling pathway plays an important role in promoting the biosynthesis of tanshinones. While individual transcription factors have been extensively studied in the context of tanshinones biosynthesis regulation, the influence of methyl jasmonate (MeJA)-induced transcriptional complexes remains unexplored. This study elucidates the positive regulatory role of the basic helix-loop-helix protein SmMYC2 in tanshinones biosynthesis in Salvia miltiorrhiza. SmMYC2 not only binds to SmGGPPS1 promoters, activating their transcription, but also interacts with SmMYB36. This interaction enhances the transcriptional activity of SmMYC2 on SmGGPPS1, thereby promoting tanshinones biosynthesis. Furthermore, we identified three JA signaling repressors, SmJAZ3, SmJAZ4, and SmJAZ8, which interact with SmMYC2. These repressors hindered the transcriptional activity of SmMYC2 on SmGGPPS1 and disrupted the interaction between SmMYC2 and SmMYB36. MeJA treatment triggered the degradation of SmJAZ3 and SmJAZ4, allowing the SmMYC2-SmMYB36 complex to subsequently activate the expression of SmGGPPS1, whereas SmJAZ8 inhibited MeJA-mediated degradation due to the absence of the LPIARR motif. These results demonstrate that the SmJAZ-SmMYC2-SmMYB36 module dynamically regulates the JA-mediated accumulation of tanshinones. Our results reveal a new regulatory network for the biosynthesis of tanshinones. This study provides valuable insight for future research on MeJA-mediated modulation of tanshinones biosynthesis.

Genome-Wide Identification and Characterization of the PHT1 Gene Family and Its Response to Mycorrhizal Symbiosis in Salvia miltiorrhiza under Phosphate Stress.

Phosphorus (P) is a vital nutrient element that is essential for plant growth and development, and arbuscular mycorrhizal fungi (AMF) can significantly enhance P absorption. The phosphate transporter protein 1 (PHT1) family mediates the uptake of P in plants. However, the PHT1 gene has not yet been characterized in Salvia miltiorrhiza. In this study, to gain insight into the functional divergence of PHT1 genes, nine SmPHT1 genes were identified in the S. miltiorrhiza genome database via bioinformatics tools. Phylogenetic analysis revealed that the PHT1 proteins of S. miltiorrhiza, Arabidopsis thaliana, and Oryza sativa could be divided into three groups. PHT1 in the same clade has a similar gene structure and motif, suggesting that the features of each clade are relatively conserved. Further tissue expression analysis revealed that SmPHT1 was expressed mainly in the roots and stems. In addition, phenotypic changes, P content, and PHT1 gene expression were analyzed in S. miltiorrhiza plants inoculated with AMF under different P conditions (0 mM, 0.1 mM, and 10 mM). P stress and AMF significantly affected the growth and P accumulation of S. miltiorrhiza. SmPHT1;6 was strongly expressed in the roots colonized by AMF, implying that SmPHT1;6 was a specific AMF-inducible PHT1. Taken together, these results provide new insights into the functional divergence and genetic redundancy of the PHT1 genes in response to P stress and AMF symbiosis in S. miltiorrhiza.

Transcriptome sequencing and metabolome analysis reveal the molecular mechanism of Salvia miltiorrhiza in response to drought stress.

Salvia miltiorrhiza is commonly used as a Chinese herbal medicine to treat different cardiovascular and cerebrovascular illnesses due to its active ingredients. Environmental conditions, especially drought stress, can affect the yield and quality of S. miltiorrhiza. However, moderate drought stress could improve the quality of S. miltiorrhiza without significantly reducing the yield, and the mechanism of this initial drought resistance is still unclear. In our study, transcriptome and metabolome analyses of S. miltiorrhiza under different drought treatment groups (CK, A, B, and C groups) were conducted to reveal the basis for its drought tolerance. We discovered that the leaves of S. miltiorrhiza under different drought treatment groups had no obvious shrinkage, and the malondialdehyde (MDA) contents as well as superoxide dismutase (SOD) and peroxidase (POD) activities dramatically increased, indicating that our drought treatment methods were moderate, and the leaves of S. miltiorrhiza began to initiate drought resistance. The morphology of root tissue had no significant change under different drought treatment groups, and the contents of four tanshinones significantly enhanced. In all, 5213, 6611, and 5241 differentially expressed genes (DEGs) were shared in the A, B, and C groups compared with the CK group, respectively. The results of KEGG and co-expression analysis showed that the DEGs involved in plant-pathogen interactions, the MAPK signaling pathway, phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction responded to drought stress and were strongly correlated with tanshinone biosynthesis. Furthermore, the results of metabolism analysis indicated that 67, 72, and 92 differentially accumulated metabolites (DAMs), including fumarate, ferulic acid, xanthohumol, and phytocassanes, which were primarily involved in phenylpropanoid biosynthesis, flavonoid biosynthesis, and diterpenoid biosynthesis pathways, were detected in these groups. These discoveries provide valuable information on the molecular mechanisms by which S. miltiorrhiza responds to drought stress and will facilitate the development of drought-resistant and high-quality S. miltiorrhiza production.

Overexpression of AtMYB2 Promotes Tolerance to Salt Stress and Accumulations of Tanshinones and Phenolic Acid in Salvia miltiorrhiza.

Salvia miltiorrhiza is a prized traditional Chinese medicinal plant species. Its red storage roots are primarily used for the treatment of cardiovascular and cerebrovascular diseases. In this study, a transcription factor gene AtMYB2 was cloned and introduced into Salvia miltiorrhiza for ectopic expression. Overexpression of AtMYB2 enhanced salt stress resistance in S. miltiorrhiza, leading to a more resilient phenotype in transgenic plants exposed to high-salinity conditions. Physiological experiments have revealed that overexpression of AtMYB2 can decrease the accumulation of reactive oxygen species (ROS) during salt stress, boost the activity of antioxidant enzymes, and mitigate oxidative damage to cell membranes. In addition, overexpression of AtMYB2 promotes the synthesis of tanshinones and phenolic acids by upregulating the expression of biosynthetic pathway genes, resulting in increased levels of these secondary metabolites. In summary, our findings demonstrate that AtMYB2 not only enhances plant tolerance to salt stress, but also increases the accumulation of secondary metabolites in S. miltiorrhiza. Our study lays a solid foundation for uncovering the molecular mechanisms governed by AtMYB2 and holds significant implications for the molecular breeding of high-quality S. miltiorrhiza varieties.

Comparative transcriptomics of two Salvia subg. Perovskia species contribute towards molecular background of abietane-type diterpenoid biosynthesis.

Tanshinones, are a group of diterpenoid red pigments present in Danshen - an important herbal drug of Traditional Chinese Medicine which is a dried root of Salvia miltiorrhiza Bunge. Some of the tanshinones are sought after as pharmacologically active natural products. To date, the biosynthetic pathway of tanshinones has been only partially elucidated. These compounds are also present in some of the other Salvia species, i.a. from subgenus Perovskia, such as S. abrotanoides (Kar.) Sytsma and S. yangii B.T. Drew. Despite of the close genetic relationship between these species, significant qualitative differences in their diterpenoid profile have been discovered. In this work, we have used the Liquid Chromatography-Mass Spectrometry analysis to follow the content of diterpenoids during the vegetation season, which confirmed our previous observations of a diverse diterpenoid profile. As metabolic differences are reflected in different transcript profile of a species or tissues, we used metabolomics-guided transcriptomic approach to select candidate genes, which expression possibly led to observed chemical differences. Using an RNA-sequencing technology we have sequenced and de novo assembled transcriptomes of leaves and roots of S. abrotanoides and S. yangii. As a result, 134,443 transcripts were annotated by UniProt and 56,693 of them were assigned as Viridiplantae. In order to seek for differences, the differential expression analysis was performed, which revealed that 463, 362, 922 and 835 genes indicated changes in expression in four comparisons. GO enrichment analysis and KEGG functional analysis of selected DEGs were performed. The homology and expression of two gene families, associated with downstream steps of tanshinone and carnosic acid biosynthesis were studied, namely: cytochromes P-450 and 2-oxoglutarate-dependend dioxygenases. Additionally, BLAST analysis revealed existence of 39 different transcripts related to abietane diterpenoid biosynthesis in transcriptomes of S. abrotanoides and S. yangii. We have used quantitative real-time RT-PCR analysis of selected candidate genes, to follow their expression levels over the vegetative season. A hypothesis of an existence of a multifunctional CYP76AH89 in transcriptomes of S. abrotanoides and S. yangii is discussed and potential roles of other CYP450 homologs are speculated. By using the comparative transcriptomic approach, we have generated a dataset of candidate genes which provides a valuable resource for further elucidation of tanshinone biosynthesis. In a long run, our investigation may lead to optimization of diterpenoid profile in S. abrotanoides and S. yangii, which may become an alternative source of tanshinones for further research on their bioactivity and pharmacological therapy.

Versatile CYP98A enzymes catalyse meta-hydroxylation reveals diversity of salvianolic acids biosynthesis.

Salvianolic acids (SA), such as rosmarinic acid (RA), danshensu (DSS), and their derivative salvianolic acid B (SAB), etc. widely existed in Lamiaceae and Boraginaceae families, are of interest due to medicinal properties in the pharmaceutical industries. Hundreds of studies in past decades described that 4-coumaroyl-CoA and 4-hydroxyphenyllactic acid (4-HPL) are common substrates to biosynthesize SA with participation of rosmarinic acid synthase (RAS) and cytochrome P450 98A (CYP98A) subfamily enzymes in different plants. However, in our recent study, several acyl donors and acceptors included DSS as well as their ester-forming products all were determined in SA-rich plants, which indicated that previous recognition to SA biosynthesis is insufficient. Here, we used Salvia miltiorrhiza, a representative important medicinal plant rich in SA, to elucidate the diversity of SA biosynthesis. Various acyl donors as well as acceptors are catalysed by SmRAS to form precursors of RA and two SmCYP98A family members, SmCYP98A14 and SmCYP98A75, are responsible for different positions' meta-hydroxylation of these precursors. SmCYP98A75 preferentially catalyses C-3' hydroxylation, and SmCYP98A14 preferentially catalyses C-3 hydroxylation in RA generation. In addition, relative to C-3' hydroxylation of the acyl acceptor moiety in RA biosynthesis, SmCYP98A75 has been verified as the first enzyme that participates in DSS formation. Furthermore, SmCYP98A enzymes knockout resulted in the decrease and overexpression leaded to dramatic increase of SA accumlation. Our study provides new insights into SA biosynthesis diversity in SA-abundant species and versatility of CYP98A enzymes catalytic preference in meta-hydroxylation reactions. Moreover, CYP98A enzymes are ideal metabolic engineering targets to elevate SA content.

A high-efficient protoplast transient system for screening gene editing elements in Salvia miltiorrhiza.

KEY MESSAGE: A high-efficiency protoplast transient system was devised to screen genome editing elements in Salvia miltiorrhiza. Medicinal plants with high-value pharmaceutical ingredients have attracted research attention due to their beneficial effects on human health. Cell wall-free protoplasts of plants can be used to evaluate the efficiency of genome editing mutagenesis. The capabilities of gene editing in medicinal plants remain to be fully explored owing to their complex genetic background and shortfall of suitable transformation. Here, we took the Salvia miltiorrhiza as a representative example for developing a method to screen favorable gene editing elements with high editing efficiency in medical plants by a PEG-mediated protoplast transformation. Results indicated that using the endogenous SmU6.1 of S. miltiorrhiza to drive sgRNA and the plant codon-optimized Cas9 driven by the promoter SlEF1α can enhance the efficiency of editing. In summary, we uncover an efficacious transient method for screening editing elements and shed new light on increasing gene editing efficiency in medicinal plants.

Identification and characterization of a novel tyrosine aminotransferase gene (SmTAT3-2) promotes the biosynthesis of phenolic acids in Salvia miltiorrhiza Bunge.

Rosmarinic acid (RA) and salvianolic acid B (SAB) are main phenolic acids in Salvia miltiorrhiza Bunge have been widely used in the treatment of cardiovascular and cerebrovascular diseases due to their excellent pharmacological activity. RA is a precursor of SAB, and tyrosine transaminase (TAT, EC 2.6.1.5) is a crucial rate-limiting enzyme in their metabolism pathway. This study identified a novel TAT gene, SmTAT3-2, and found that it is a new transcript derived from unconventional splicing of SmTAT3. We used different substrates for enzymatic reaction with SmTAT1, SmTAT3 and SmTAT3-2. Subcellular localization of SmTAT1 and SmTAT3-2 was completed based on submicroscopic techniques. In addition, they were overexpressed and CRISPR/Cas9 gene edited in hairy roots of S. miltiorrhiza. Revealed SmTAT3-2 and SmTAT1 showed a stronger affinity for L-tyrosine than SmTAT3, localized in the cytoplasm, and promoted the synthesis of phenolic acid. In overexpressed SmTAT3-2 hairy roots, the content of RA and SAB was significantly increased by 2.53 and 3.38 fold, respectively, which was significantly higher than that of overexpressed SmTAT1 strain compared with EV strain. These findings provide a valuable key enzyme gene for the phenolic acids metabolism pathway and offer a theoretical basis for the clinical application.

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.

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.

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.

Drug monomers from Salvia miltiorrhiza Bge. promoting tight junction protein expression for therapeutic effects on lung cancer.

Salvia miltiorrhiza Bge. is a traditional Chinese medicine (TCM) that has been used for treatment of various diseases, including cancer by activating blood circulation and removing blood stasis. Tanshinone (TanIIA) and cryptotanshinone (CPT) are major lipophilic compounds extracted from the root of Salvia miltiorrhiza Bge., which are considered to be the effective compounds affecting the efficacy of the anti-tumor therapy of Salvia miltiorrhiza Bge. We have explored the mechanism of CPT and TanIIA exerting inhibition in non-small cell lung cancer (NSCLC) to provide experimental data support for guiding the translational development and clinical application of anti-tumor components of TCM. The subcutaneous tumor model and in vitro culture model of A549 cells was constructed to evaluate CPT and TanIIA's tumour-inhibitory effect respectively. RNA sequencing (RNA-seq) and bioinformatics analysis were conducted to identify differentially expressed genes (DEGs) and signalling pathways related to CPT and TanIIA treatment. qRT-PCR and Western blot were used to explore the mechanism of CPT and TanIIA intervention on NSCLC. Both CPT and TanIIA significantly inhibited the proliferation of A549 tumor cells and tumor growth in animal models. After intervention, the migration ability decreased and the level of apoptosis increased. RNA-seq results showed that both CPT and TanIIA could cause gene differential expression, miR-21-5p as one of the most significant gene expression differences between the two groups, and could act on cell connectivity. CPT and TanIIA play a regulatory role in regulating tight junction proteins (Occludin and ZO1), and Occludin mRNA and protein levels were reduced in an in vitro miR-21-5p overexpression A549 cell model. The mechanisms may be related to the reduction of miR-21-5p expression to increase the level of promoted tight junction protein expression for the purpose of inhibiting proliferation and invasion of NSCLC.

Genotype-Controlled Vertical Transmission Exerts Selective Pressure on Community Assembly of Salvia miltiorrhiza.

The plant's endophytic fungi play an important role in promoting host development and metabolism. Studies have shown that the factors affecting the assembly of the endophyte community mainly include host genotype, vertical transmission, and soil origin. However, we do not know the role of vertically transmitted endohytic fungi influences on the host-plant's endophytic community assembly. Salvia miltiorrhiza from three production areas were used as research objects; we constructed three production area genotypes of S. miltiorrhiza regenerated seedlings simultaneously. Based on high-throughput sequencing, we analyzed the effects of genotype, soil origin, and vertical transmission on endophytic fungal communities. The results show that the community of soil origins significantly affected the endophytic fungal community in the regenerated seedlings of S. miltiorrhiza. The influence of genotype on community composition occurs through a specific mechanism. Genotype may selectively screen certain communities into the seed, thereby exerting selection pressure on the community composition process of offspring. As the number of offspring increases gradually, the microbiota, controlled by genotype and transmitted vertically, stabilizes, ultimately resulting in a significant effect of genotype on community composition.Furthermore, we observed that the taxa influencing the active ingredients are also selected as the vertically transmitted community. Moreover, the absence of an initial vertically transmitted community in S. miltiorrhiza makes it more vulnerable to infection by pathogenic fungi. Therefore, it is crucial to investigate and comprehend the selection model of the vertically transmitted community under varying genotypes and soil conditions. This research holds significant implications for enhancing the quality and yield of medicinal plants and economic crops.

Salicylic acid regulates phenolic acid biosynthesis via SmNPR1-SmTGA2/SmNPR4 modules in Salvia miltiorrhiza.

Phenolic acids are the main active ingredients in Salvia miltiorrhiza, which can be used for the treatment of many diseases, particularly cardiovascular diseases. It is known that salicylic acid (SA) can enhance phenolic acid content, but the molecular mechanism of its regulation is still unclear. Nonexpresser of PR genes 1 (NPR1) plays a positive role in the SA signaling pathway. In this study, we identified a SmNPR1 gene that responds to SA induction and systematically investigated its function. We found that SmNPR1 positively affected phenolic acid biosynthesis. Then, we identified a novel TGA transcription factor, SmTGA2, which interacts with SmNPR1. SmTGA2 positively regulates phenolic acid biosynthesis by directly up-regulating SmCYP98A14 expression. After double-gene transgenic analysis and other biochemical assays, it was found that SmNPR1 and SmTGA2 work synergistically to regulate phenolic acid biosynthesis. In addition, SmNPR4 forms a heterodimer with SmNPR1 to inhibit the function of SmNPR1, and SA can alleviate this effect. Collectively, these findings elucidate the molecular mechanism underlying the regulation of phenolic acid biosynthesis by SmNPR1-SmTGA2/SmNPR4 modules and provide novel insights into the SA signaling pathway regulating plant secondary metabolism.