JA-Responsive Transcription Factor SmMYB97 Promotes Phenolic Acid and Tanshinone Accumulation in Salvia miltiorrhiza.

Phenolic acids and tanshinones are active principles in Salvia miltiorrhiza Bunge administered for cardiovascular and cerebrovascular diseases. Jasmonic acid (JA) promotes secondary metabolite accumulation, but the regulatory mechanism is unknown in S. miltiorrhiza. We identified and characterized the JA-responsive gene SmMYB97. Multiple sequence alignment and phylogenetic tree analyses showed that SmMYB97 was clustered with AtMYB11, AtMYB12, and ZmP1 in the subgroup S7 regulating flavonol biosynthesis. SmMYB97 was highly expressed in S. miltiorrhiza leaves and induced by methyl jasmonate (MeJA). SmMYB97 was localized in the nucleus and had strong transcriptional activation activity. SmMYB97 overexpression increased phenolic acid and tanshinone biosynthesis and upregulated the genes implicated in these processes. Yeast one-hybrid and transient transcriptional activity assays disclosed that SmMYB97 binds the PAL1, TAT1, CPS1, and KSL1 promoter regions. SmJAZ8 interacts with SmMYB97 and downregulates the genes that it controls. This study partially clarified the regulatory network of MeJA-mediated secondary metabolite biosynthesis in S. miltiorrhiza.

Core Microbiome of Medicinal Plant Salvia miltiorrhiza Seed: A Rich Reservoir of Beneficial Microbes for Secondary Metabolism?

Seed microbiome includes special endophytic or epiphytic microbial taxa associated with seeds, which affects seed germination, plant growth, and health. Here, we analyzed the core microbiome of 21 Salvia miltiorrhiza seeds from seven different geographic origins using 16S rDNA and ITS amplicon sequencing, followed by bioinformatics analysis. The whole bacterial microbiome was classified into 17 microbial phyla and 39 classes. Gammaproteobacteria (67.6%), Alphaproteobacteria (15.6%), Betaproteobacteria (2.6%), Sphingobacteria (5.0%), Bacilli (4.6%), and Actinobacteria (2.9%) belonged to the core bacterial microbiome. Dothideomycetes comprised 94% of core fungal microbiome in S. miltiorrhiza seeds, and another two dominant classes were Leotiomycetes (3.0%) and Tremellomycetes (2.0%). We found that terpenoid backbone biosynthesis, degradation of limonene, pinene, and geraniol, and prenyltransferases, were overrepresented in the core bacterial microbiome using phylogenetic examination of communities by reconstruction of unobserved states (PICRUSt) software. We also found that the bacterial genera Pantoea, Pseudomonas, and Sphingomonas were enriched core taxa and overlapped among S. miltiorrhiza, maize, bean, and rice, while a fungal genus, Alternaria, was shared within S. miltiorrhiza, bean, and Brassicaceae families. These findings highlight that seed-associated microbiomeis an important component of plant microbiomes, which may be a gene reservoir for secondary metabolism in medicinal plants.

Genome-Wide Identification of the AP2/ERF Gene Family Involved in Active Constituent Biosynthesis in.

Tanshinones and phenolic acids are the major bioactive constituents in the traditional medicinal crop ; however, transcription factors (TFs) are seldom investigated with regard to their regulation of the biosynthesis of these compounds. Here a complete overview of the APETALA2/ethylene-responsive factor (AP2/ERF) transcription factor family in is provided, including phylogeny, gene structure, conserved motifs, and gene expression profiles of different organs (root, stem, leaf, flower) and root tissues (periderm, phloem, xylem). In total, 170 AP2/ERF genes were identified and divided into five relatively conserved subfamilies, including AP2 (25 genes), DREB (61 genes), ethylene responsive factor (ERF; 79 genes), RAV (4 genes), and Soloist (1 gene). According to the distribution of bioactive constituents and the expression patterns of AP2/ERF genes in different organs and root tissues, the genes related to the biosynthesis of bioactive constituents were selected. On the basis of quantitative real-time polymerase chain reaction (qRT-PCR) analysis, coexpression analysis, and the prediction of -regulatory elements in the promoters, we propose that two genes ( and ) regulate tanshinone biosynthesis and two genes ( and ) participate in controlling phenolic acid biosynthesis. The genes related to tanshinone biosynthesis belong to the ERF-B3 subgroup. In contrast, the genes predicted to regulate phenolic acid biosynthesis belong to the ERF-B1 and ERF-B4 subgroups. These results provide a foundation for future functional characterization of AP2/ERF genes to enhance the biosynthesis of the bioactive compounds of .

Functional Analysis of the Isopentenyl Diphosphate Isomerase of Salvia miltiorrhiza via Color Complementation and RNA Interference.

Isopentenyl diphosphate isomerase (IPI) catalyzes the isomerization between the common terpene precursor substances isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) during the terpenoid biosynthesis process. In this study, tissue expression analysis revealed that the expression level of the Salvia miltiorrhiza IPI1 gene (SmIPI1) was higher in the leaves than in the roots and stems. Furthermore, color complementation and RNA interference methods were used to verify the function of the SmIPI1 gene from two aspects. A recombinant SmIPI1 plasmid was successfully constructed and transferred into engineered E. coli for validating the function of SmIPI1 through the color difference in comparison to the control group; the observed color difference indicated that SmIPI1 served in promoting the accumulation of lycopene. Transformant hairy root lines with RNA interference of SmIPI1 were successfully constructed mediated by Agrobacterium rhizogenes ACCC 10060. RNA interference hairy roots had a severe phenotype characterized by withering, deformity or even death. The mRNA expression level of SmIPI1 in the RSi3 root line was only 8.4% of that of the wild type. Furthermore the tanshinone content was too low to be detected in the RNA interference lines. These results suggest that SmIPI1 plays a critical role in terpenoid metabolic pathways. Addition of an exogenous SmIPI1 gene promoted metabolic flow toward the biosynthesis of carotenoids in E. coli, and SmIPI1 interference in S. miltiorrhiza hairy roots may cause interruption of the 2-C-methyl-D-erythritol-4-phosphate metabolic pathway.

[Cloning and prokaryotic expression analysis of squalene synthase 2 (SQS2) from Salvia miltiorrhiza f. alba].

According to the designed specific primers of gene fragment based on the Salvia miltiorrhiza transcriptome data, a full-length cDNA sequence of SQS2 from S. miltiorrhiza f. alba was cloned by the method of reverse transcription polymerase chain reaction (RT-PCR). The SmSQS2 cDNA sequence was obtained, this sequence is named SmSQS2 and its GenBank registration number is KM244731. The full length of SmSQS2 cDNA was 1245 bp, encoding 414 amino acids including 5'UTR 115 bp and 3'UTR 237 bp. Sequence alignment and phylogenetic analysis demonstrated that SmSQS2 had relative close relationship to the SQS2 of S. miltiorrhiza. The induction of E. coli [pET28-SQS2] in different temperature, induction time, IPTG concentrations and density of inducing host bacterium (A600) were performed, Shaking the culture at 30 degrees C until the A600 is approximately 0.6 and add IPTG to final concentration of 0.2 mmol x L(-1), and then the optimal expression of SmSQS2 recombinant protein were accumulated after the induction time of 20 h. The research provided important base for the study of sterol and terpene biosynthesis of SQS2 in S. miltiorrhiza f. alba.

Genome-wide characterization and comparative analysis of R2R3-MYB transcription factors shows the complexity of MYB-associated regulatory networks in Salvia miltiorrhiza.

BACKGROUND: MYB is the largest plant transcription factor gene family playing vital roles in plant growth and development. However, it has not been systematically studied in Salvia miltiorrhiza, an economically important medicinal plant. RESULTS: Here we report the genome-wide identification and characterization of 110 R2R3-MYBs, the largest subfamily of MYBs in S. miltiorrhiza. The MYB domain and other motifs of SmMYBs are largely conserved with Arabidopsis AtMYBs, whereas the divergence of SmMYBs and AtMYBs also exists, suggesting the conservation and diversity of plant MYBs. SmMYBs and AtMYBs may be classified into 37 subgroups, of which 31 include proteins from S. miltiorrhiza and Arabidopsis, whereas 6 are specific to a species, indicating that the majority of MYBs play conserved roles, while others may exhibit species-specialized functions. SmMYBs are differentially expressed in various tissues of S. miltiorrhiza. The expression profiles are largely consistent with known functions of their Arabidopsis counterparts. The expression of a subset of SmMYBs is regulated by microRNAs, such as miR159, miR319, miR828 and miR858. Based on functional conservation of MYBs in a subgroup, SmMYBs potentially involved in the biosynthesis of bioactive compounds were identified. CONCLUSIONS: A total of 110 R2R3-MYBs were identified and analyzed. The results suggest the complexity of MYB-mediated regulatory networks in S. miltiorrhiza and provide a foundation for understanding the regulatory mechanism of SmMYBs.

Transcriptome analysis of medicinal plant Salvia miltiorrhiza and identification of genes related to tanshinone biosynthesis.

Salvia miltiorrhiza Bunge, a perennial plant of Lamiaceae, accumulates abietane-type diterpenoids of tanshinones in root, which have been used as traditional Chinese medicine to treat neuroasthenic insomnia and cardiovascular diseases. However, to date the biosynthetic pathway of tanshinones is only partially elucidated and the mechanism for their root-specific accumulation remains unknown. To identify enzymes and transcriptional regulators involved in the biosynthesis of tanshinones, we conducted transcriptome profiling of S. miltiorrhiza root and leaf tissues using the 454 GS-FLX pyrosequencing platform, which generated 550,546 and 525,292 reads, respectively. RNA sequencing reads were assembled and clustered into 64,139 unigenes (29,883 isotigs and 34,256 singletons). NCBI non-redundant protein databases (NR) and Swiss-Prot database searches anchored 32,096 unigenes (50%) with functional annotations based on sequence similarities. Further assignments with Gene Ontology (GO) terms and KEGG biochemical pathways identified 168 unigenes referring to the terpenoid backbone biosynthesis (including 144 MEP and MVA pathway genes and 24 terpene synthases). Comparative analysis of the transcriptomes identified 2,863 unigenes that were highly expressed in roots, including those encoding enzymes of early steps of tanshinone biosynthetic pathway, such as copalyl diphosphate synthase (SmCPS), kaurene synthase-like (SmKSL) and CYP76AH1. Other differentially expressed unigenes predicted to be related to tanshinone biosynthesis fall into cytochrome P450 monooxygenases, dehydrogenases and reductases, as well as regulatory factors. In addition, 21 P450 genes were selectively confirmed by real-time PCR. Thus we have generated a large unigene dataset which provides a valuable resource for further investigation of the radix development and biosynthesis of tanshinones.

[Cloning and bioinformatics analysis of chorismate mutase gene from Salvia miltiorrhiza].

Chorismate mutase catalyzes the conversion of chorismate to prephenate that is the first committed step in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine. A chorismate mutase gene, designated SmCM1, was isolated from Salvia miltiorrhiza by using RT-PCR. The full length of SmCM1 cDNA consists of 948 nucleotides and has an open reading frame of 765 bp. The deduced amino acid sequence of SmCM1 has 255 amino acid residues which forms a 36.0 kD polypeptide with calculated pI of 6.41 as expected. The putative polypeptide contains a CM_2 super family function domain. Blast W results showed that SmCM1 had 70% of the similarity with Petunia x hybrid CM, 72% of the similarity with Arabidopsis thaliana CM, and 64% of similarity with Populus trichocarpa CM. The transcription level of SmCM1 in root, stem and leaf was analysed by realtime quantitative PCR. The results showed the expression level of the SmCM1 in leaf was highest, and lowest in root. Yeast extract and silver ion joint induction could markedly stimulate the increase of mRNA expression of SmCM1 and its upstream 3-deoxy-7- phosphoheptulonate synthase (DAHPS) and chorismate synthase (CS). It was 7.9, 5.5 and 9.8 times of control on 8 h after induction, respectively.

[Expression analysis and subcellular localization of an ERF transcription factor from Salvia miltiorrhiza].

OBJECTIVE: A SmERF1 gene was isolated from Salvia miltiorrhiza, and expression patterns to different stress condition were analysed in the root tissues of S. miltiorrhiza. METHOD: The cDNA of SmERF1 gene from S. miltiorrhiza was isolated by RTPCR, and the phylogenetic tree using the neighbour-joining tree method in Mega 5 was obtained. To confirm the protein is likely to localize in the nucleus, the SmERF1 coding region was fused to the N-terminus of the GFP gene under the control of the CaMV 35S promoter and transferred into onion epidermal cells using the particle bombardment method. Semi-quantitative RT-PCR analysis revealed different expression pattern of SmERF1 gene in response to exogenous ABA, MeJA and SA. RESULT: The phylogenetic tree analysis revealed that SmERF1 is most similar to AP2/ERF VII subgroup members. The transient expression of the SmERF1::GFP fusion protein indicated that the SmERF1 was exclusively localized to the nucleus. The transcript of SmERF1 highly accumulated when the plants were treated with MeJA, while accumulated slightly in response to exogenous ABA, salicylic acid. CONCLUSION: These results suggest hormone such as ABA, MeJA and SA signaling pathways can be involved in the activation and inhibition of the SmERF1.

Diversity evaluation of Salvia miltiorrhiza using ISSR markers.

Salvia miltiorrhiza is a well-known medicinal plant and functional food in Asia. The range of quality among its germplasms is irregular, which inevitably affects its health and economic benefits. We established a system comprising phenotypic characteristics, ISSR markers, and active constituents to facilitate the comprehensive evaluation of this species. Concerning the phenotypic traits, 55 germplasms were characterized and divided into eight groups. ISSR molecular markers were employed to detect polymorphisms and distinguish germplasms by integrating with phenotypic characteristics. In terms of economic benefits, we were able to screen out the tall-stem and purple-stem types, both with good yields (root biomass) and high contents of active constituents, as members of a preferred-quality group in S. miltiorrhiza. Our study is the first to provide an overall assessment of different S. miltiorrhiza germplasms. The integrated investigation of the phenotypic, genetic, and phytochemical diversity of S. miltiorrhiza germplasms demonstrates the great potential of diverse genotypes to be exploited by plant breeders.

[Cloning and expression analysis of a new 3-hydroxy-3-methylglutaryl coenzyme A reductase gene from Salvia miltiorrhiza (SmHMGR3)].

OBJECTIVE: To clone and analysis a new 3-hydroxy-3methylglutary CoA reductase cDNA from Salvia miltiorrhiza (SmHMGR3). METHOD: Transcription database of S. miltiorrhiza was used and a new regulatory gene from terpene secondary metabolic pathway has been cloned. ORF Finder was used to find the open reading frame of SmHMGR3 cDNA and ClustalW has been performed to analysis the multiple amino acid sequence alignment. Phylogenetic tree has been constructed using MEGA5.0. RT-PCR has been applied to detect the transcription level of SmHMGR3 in roots, stems and leaves from flowering S. miltiorrhiza plant. The mRNA level of SmHMGR3 gene from hairy roots was detected after elicitor Ag+ supplied. RESULT: The SmHMGR3 cDNA sequence was obtained. The total length of SmHMGR3 cDNA was 1,692 bp encoding 563 amino acids. The homology rate was 75.04% and 80.64% comparing with SmHMGR1 and SmHMGR2 respectively. QRT-PCR results showed that the highest mRNA level existed in leaves of S. miltiorrhiza. After induced by Ag for 24h, the transcription level reached the highest value. CONCLUSION: A new SmHMGR3 gene has been obtained for the first time, and which can provide the new target for the further studies about tepenes metabolism.

[Micromorphological comparative identification between several Chinese herbal medicines and their counterfeits].

OBJECTIVE: To identify comparatively several commercial Chinese herbal medicines and their counterfeits. METHOD: The micromorphological characters were identified. The shape, surface, section and other characters of the medicinal materials were identified by using anatomical lens and scanning apparatus. Pictures were taken and saved. RESULT: Main micromorphological differences between several Chinese herbal medicine including Lonicera macranthoides, L. similis, Cuminum cyminum, Plantago asiatica, Cuscuta chinensis, Sinapis alba, Salvia miltiorrhiza and their counterfeits were identified. CONCLUSION: The reference for the authenticity identification of Chinese herbal medicine and helpful experiences for the research of the same subject were provided.

Rational design of core-shell molecularly imprinted polymer based on computational simulation and Doehlert experimental optimization: application to the separation of tanshinone IIA from Salvia miltiorrhiza Bunge.

Computational simulation and Doehlert experimental optimization were done for the rational design of a core-shell molecularly imprinted polymer (CS-MIP) for use in the highly selective separation of Tanshinone IIA (TSIIA) from the crude extracts of Salvia miltiorrhiza Bunge (SMB). The functional monomer layer of the polymer shells directed the selective occurrence of imprinting polymerization at the surface of silica through the copolymerization of vinyl end groups with functional monomers and also drove TSIIA templates into the formed polymer shells through the charge-transfer complex interactions between TSIIA and the functional monomer layer. As a result, the maximum rebinding capacity was achieved with the use of optimal grafting ratio by the Doehlert design. The CS-MIP exhibited high recognition selectivity and binding affinity to TSIIA. When the imprinted particles were used as dispersive solid phase extraction sorbents, the recovery yield of TSIIA reached 93% by a one-step extraction from the crude extracts of SMB, and the purity of TSIIA was larger than 98% by HPLC analysis. These results show the possibility of a highly selective separation and enrichment of TSIIA from the SMB using the TSIIA-imprinted core-shell molecularly imprinted polymers.

Genome-wide identification and characterization of novel genes involved in terpenoid biosynthesis in Salvia miltiorrhiza.

Terpenoids are the largest class of plant secondary metabolites and have attracted widespread interest. Salvia miltiorrhiza, belonging to the largest and most widely distributed genus in the mint family, is a model medicinal plant with great economic and medicinal value. Diterpenoid tanshinones are the major lipophilic bioactive components in S. miltiorrhiza. Systematic analysis of genes involved in terpenoid biosynthesis has not been reported to date. Searching the recently available working draft of the S. miltiorrhiza genome, 40 terpenoid biosynthesis-related genes were identified, of which 27 are novel. These genes are members of 19 families, which encode all of the enzymes involved in the biosynthesis of the universal isoprene precursor isopentenyl diphosphate and its isomer dimethylallyl diphosphate, and two enzymes associated with the biosynthesis of labdane-related diterpenoids. Through a systematic analysis, it was found that 20 of the 40 genes could be involved in tanshinone biosynthesis. Using a comprehensive approach, the intron/exon structures and expression patterns of all identified genes and their responses to methyl jasmonate treatment were analysed. The conserved domains and phylogenetic relationships among the deduced S. miltiorrhiza proteins and their homologues isolated from other plant species were revealed. It was discovered that some of the key enzymes, such as 1-deoxy-D-xylulose 5-phosphate synthase, 4-hydroxy-3-methylbut-2-enyl diphosphate reductase, hydroxymethylglutaryl-CoA reductase, and geranylgeranyl diphosphate synthase, are encoded by multiple gene members with different expression patterns and subcellular localizations, and both homomeric and heteromeric geranyl diphosphate synthases exist in S. miltiorrhiza. The results suggest the complexity of terpenoid biosynthesis and the existence of metabolic channels for diverse terpenoids in S. miltiorrhiza and provide useful information for improving tanshinone production through genetic engineering.

[Cloning and bioinformatics analysis of 2-c-methyl-D-erythritol 2,4-cyclodiphosphate synthase gene in Salvia miltiorrhiza].

OBJECTIVE: To clone and analysis a 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (SmMCS) full-length eDNA from Salvia miltiorrhiza hairy roots. METHOD: A full-length eDNA of SmMCS has been cloned by designing specific primers according to the transcriptome database and using the RACE strategy. ORF Finder was used to find the open reading frame of SmMCS cDNA and ClustalW has been performed to analysis the multiple amino acid sequence alignment. Phylogenetic tree has been constructed using MEGA 5. 1. Real-time quantitative PCR have been applied to detect the transcription level of SmMCS from hairy roots after elicitor Ag+ supplied. RESULT: The SmMCS cDNA sequence was obtained. The full length of SmMCS (DNA was 988 bp encoding 234 amino acids. The deduced protein had isoelectric point (pI) of 8.53 and a calculated molecular weight about 24. 6 kDa. Results of real time PCR indicated that elicitor of Ag+ stimulated the increase of mRNA expression of SmMCS in hairy roots, and were increased dramatically at 12 h. CONCLUSION: The full-length cDNA of SmMCS was cloned from S. miltiorrhiza hairy root,which can provide a gene target for further studies of tanshinones biosynthesis and terpenoid secondary metabolites.

[Molecular cloning and SNP analysis of a acetyl-CoA C-acetyltransferase gene (SmAACT) from Salvia miltiorrhiza].

Acetyl-CoA C-acetyltransferase (AACT) is the first enzyme in the terpene synthesis pathway, catalyzed two units of acetyl-CoA to acetoacetyl-CoA. In order to study the tanshinone biosynthesis in Salvia miltiorrhiza, a novel AACT gene, SmAACT, was cloned using cDNA microarray and RACE strategy. The full length cDNA of SmAACT is 1 623 bp (accession No. EF635969), which contained a 1 200 bp open reading frame (ORF) encoding a 399 amino acid protein. Nine introns were found in the genomic sequence. SmAACT was upregulated by YE and Ag+ elicitors both with cDNA microarray and quantitative RT-PCR analyses along with the accumulation of tanshinones. Sequence homology comparison and phylogenetic analysis all suggested that SmAACT belonged to the class of acetyl-CoA C-acetyltransferase. The transcription level of SmAACT was relatively higher in root than that in stem and leaf tissues. SNP analysis revealed that SmAACT was highly variable in the region of 6 to 9 introns with 33 SNPs in the 600 bp region, there are 5 SNPs in the cDNA region while they are all synonymous cSNPs. Some special genotypes were found in Salvia miltiorrhiza from different areas. SmAACT will be an useful gene for further analyze the mechanism of gene regulation among the tanshinones biosynthesis.

[Comprehensive characterization of main components and microstructures in five different species of Salvia miltiorrhiza bge].

Studied with X-ray fluorescence spectrum analytic (XRF), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR) for five different species of Salvia miltiorrhiza bge grew in Anguo, the intrinsic components and microstructures were determined and comprehensive characterization was carried out. The figure of comprehensive characterization can describe characteristics of intrinsic components from elements, crystal and amorphous active component, it can give an intuitive description for the same components and subtle differences in the intrinsic components of Salvia miltiorrhiza bge, which are different idioplasmatic and same species. It is the ideal method because of the simple preparation of sample, rapid and fine accurate measurement with reproducibility and objectivity, so that it can be used for breeding of fine varieties of Chinese medicinal materials, Chinese medicinal materials GAP guidance of growing conditions, medicinal origin characteristics, the intrinsic composition and microstructure characterization, quality control and authenticity of the identification.

Combined NMR and LC-DAD-MS analysis reveals comprehensive metabonomic variations for three phenotypic cultivars of Salvia Miltiorrhiza Bunge.

Metabonomic analysis is an important molecular phenotyping method for understanding plant ecotypic variations and gene functions. Here, we systematically characterized the metabonomic variations associated with three Salvia miltiorrhiza Bunge (SMB) cultivars using the combined NMR and LC-DAD-MS detections in conjunction with multivariate data analysis. Our results indicated that NMR methods were effective to quantitatively detect the abundant plant metabolites including both the primary and secondary metabolites whereas the LC-DAD-MS methods were excellent for selectively detecting the secondary metabolites. We found that the SMB metabonome was dominated by 28 primary metabolites including sugars, amino acids, and carboxylic acids and 4 polyphenolic secondary metabolites, among which N-acetylglutamate, asparate, fumurate, and yunnaneic acid D were reported for the first time in this plant. We also found that three SMB cultivars growing at the same location had significant metabonomic differences in terms of metabolisms of carbohydrates, amino acids, and choline, TCA cycle, and the shikimate-mediated secondary metabolisms. We further found that the same SMB cultivar growing at different locations differed in their metabonome. These results provided important information on the ecotypic dependence of SMB metabonome on the growing environment and demonstrated that the combination of NMR and LC-MS methods was effective for plant metabonomic phenotype analysis.

Genetic diversity and population structure of Salvia miltiorrhiza Bge in China revealed by ISSR and SRAP.

Salvia miltiorrhiza Bge is a traditional Chinese medicinal herb used as an important drug to cure cardiovascular diseases. In this work, inter simple sequence repeats (ISSR) and sequence related amplified polymorphism (SRAP) markers, were applied to assess the level and pattern of genetic diversity in five important cultivated populations of S. miltiorrhiza. Among these populations, 120 bands were amplified by 5 ISSR primers, of which all were polymorphic, and 110 polymorphic bands (90.16%) were observed in 122 bands amplified by 6 SRAP primers. A high levels of genetic diversity at the species level was detected with Hs = 0.1951, 0.1927 respectively. Analysis of molecular variance revealed that a greater proportion of total genetic variation existed within populations (86.64 and 84.83% respectively) rather than among populations (13.36 and 15.17% respectively). Cluster analysis divided the five populations into two groups. The genetic relationships among populations have low correlation with their geographical distribution (Mantel test; r = 0.4870 and 0.5740 respectively). The study indicated that both ISSR and SRAP markers were effective and reliable for assessing the degree of genetic variation of S. miltiorrhiza. Our results suggested that random collecting, preserving and planting seeds without deliberate selection might be an efficient way to conserve genetic resources of medicinal plants. Their effective use was also discussed on the further breeding.

[Cloning and characterization of geranylgeranyl diphosphate synthase gene of Salvia miltiorrhia].

OBJECTIVE: To obtain geranylgeranyl diphosphate synthase gene of Salvia miltiorrhiza, and conduct bioinformatic and transcript expression analysis of the cloned SmGGPS1 gene. METHOD: The degenerate primers were designed based on the conservative regions of GGPS protein sequences from public databases. The target gene was obtained from root of S. miltiorrhiza by use of homologous cDNA amplification and RACE technologies. The sequence alignment was performed using BLAST. The open reading frame was identified by use of the ORF Finder. The protein domains were defined by use of Prosite software and the signal peptide sequence was predicted by Target P1.1. MEGA4.0 was used to conduct multiple amino acid sequence alignment and construct the phylogenetic tree. Roots and leaves at the seedlings stage and roots, stems, leaves, buds and flowers in the flowering stage were sampled for transcript analysis. Semi-quantitative RT-PCR was used to detect the gene expression level. The complete gene of GGPS was obtained from S. miltiorrhiza genomic DNA by PCR using the cDNA-derived specific primer. The gene structure of GGPS was analyzed by comparison of the genomic DNA and its cDNA. RESULT: The obtained 1 298 bp SmGGPS1 cDNA sequence contains an 1095 bp ORF, encoding 364 amino acids. It is predicted that it has a plastid targeting signal peptide of approximately 52 amino acid at the N-terminal end. It is to believe that this is the polyprenyl synthetase signature, and nucleic acid sequence comparison revealed that SmGGPS1 ORF has more than 60% identity to the reported GGPS. RT-PCR semi-quantitative analysis showed that the gene expresses in the all tested tissues, and with much higher level of expression in the leaves in the flowering stage. SmGGPS1 has a 397 bp intron. CONCLUSION: For the first time the cloning of geranylgeranyl diphosphate synthase gene from S. miltiorrhiza was reported, and it provides a good basis for further functional study of SmGGPS1.