The diversity of plant monoterpenes is largely based on the catalytic activity of monoterpene synthases. Additionally, copy number variation of monoterpene synthase genes may contribute to the ...quantity of transcripts and hence to the essential oil profile.
This study used whole-genome sequencing and digital PCR for the measurement of copy number variation and quantification of gene expression in three closely related Salvia species, namely Salvia officinalis, Salvia pomifera and Salvia fruticosa. Twelve, 13 and 15 monoterpene synthase-encoding open-reading frames were predicted for Salvia officinalis, Salvia pomifera and Salvia fruticosa, respectively. In Salvia officinalis, one of the open reading frames was disrupted indicating a pseudogene. Monoterpene synthase genes were generally single copy per haploid genome, only a few were double or triple copy genes.
Expression levels of monoterpene synthases in leaves corresponded generally well with essential oil composition. In some cases, a higher expression level of a certain monoterpene synthase could be explained by its duplication or triplication. The very high content of thujones in Salvia pomifera, for example, was accompanied by gene duplication and increased gene expression of (+)-sabinene synthase responsible for the thujone precursor sabinene.
In Salvia officinalis, three individuals different in their essential oil profile showed significant differences in their monoterpene synthase expression levels corresponding roughly to the profile of the essential oils.
Transcript expression of monoterpene synthase genes were measured in leaf, calyx and corolla. The corolla differed significantly from leaves, while calyces usually showed a profile intermediary between leaf and corolla.
•Salvia officinalis, S. fruticosa and S. pomifera share the same monoterpenes but with different relation.•In S. officinalis 12 monoterpene synthases (TPS), in S. fruticosa 15 TPS and in S. pomifera 13 TPS identified.•Most TPS are single copy genes, a few with two or three copies.•Good correspondence between TPS expression levels and monoterpene profiles.•In some cases higher expression levels could be explained by copy number variation.
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
...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
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
, and
were enriched core taxa and overlapped among
, maize, bean, and rice, while a fungal genus,
, was shared within
, 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.
alpha-Bisabolol is a commercially important aroma chemical currently obtained from the Candeia tree (Vanillosmopsis erythropappa). Continuous unsustainable harvesting of the Candeia tree has prompted ...the urgent need to identify alternative crops as a source of this commercially important sesquiterpene alcohol. A chemotaxonomic assessment of two Salvia species indigenous to South Africa is presented and recommended as a potential source of alpha-bisabolol. The essential oil obtained by hydrodistillation of the aerial parts was analysed by gas chromatography coupled to mass spectrometry (GCaMS) and mid-infrared spectroscopy (MIRS). Orthogonal projections to latent structuresadiscriminant analysis (OPLSaDA) were used for multivariate classification of the oils based on GCaMS and MIRS data. Partial least squares (PLS) calibration models were developed on the MIRS data for the quantification of alpha-bisabolol using GCaMS as the reference method. A clear distinction between Salvia stenophylla and Salvia runcinata oils was observed using OPLSaDA on both GCaMS and MIRS data. The MIR calibration model showed high coefficient of determination (R2 = 0.999) and low error of prediction (RMSEP = 0.540%) for alpha-bisabolol content.
is a well-known traditional Chinese herb which is used to treat heart disease.
is a substitute product for
in the medicinal field. Previous study has shown that phosphate (Pi) deficiency could ...promote the accumulation of secondary metabolism in herbs, and it has also developed a strategy for saving Pi resources and increasing the yield of active substances in herbs. In the present study, the hairy roots of
and
were used to identify the Pi deficiency response mechanisms of these two
species. The results showed that Pi deficiency increased the accumulation of specifically secondary metabolites, such as phenolic acids and tanshinones, which were caused by promoting the expression levels of key enzyme genes. In addition, Pi deficiency promoted the antioxidant activity in these two
species. The data demonstrated that Pi deficiency increased the quality of the medicinal material in the plant. The hairy roots of
were more adaptive to Pi deficiency than those of
in terms of biomass, secondary metabolism, and antioxidant activity. The results of this study provide insights into breeding herbs that are better adapted to Pi deficiency, which could increase the yield of active ingredients in herbs and save Pi resources.
The genus Salvia includes an enormous assemblage of nearly 1,000 species dispersed around the world. Due to possible threats to this genus, there is an immediate requirement to evaluate the diversity ...of its wild populations. ISSR and RAPD molecular techniques were used to evaluate the genetic relationships among twenty-one ecotypes of eight Salvia species. Amplification of genomic DNA using 23 primers (15 RAPD and eight ISSR) produced 280 bands, of which 91% were polymorphic. The results of marker parameters showed no clear difference between two marker systems. It was generally observed that both ISSR and RAPD markers had similar efficiency in detecting genetic polymorphisms with remarkable ability to differentiate the closely related ecotypes of Salvia. Nei's similarity coefficients for these techniques ranged from 0.48 to 0.98. Based on the results of clustering, PCoA and AMOVA, the genetic diversity between and within species was confirmed. So, conservation and domestication of the genus Salvia must be due to levels of genetic variations.
The chemistry and biological activity of cuticular waxes and the secondary metabolites produced in the indumentum of different plant organs has been attracting the interest of botanists. This work ...was aimed to investigate the chemistry and antibacterial activity of the surface extracts (SE) of different organs of six Salvia species. The cuticles and indumenta of the leaves, calyxes, and stems of Salvia atropatana Bunge., S. lachnocalyx Hedge., S. ceratophylla L., S. palaestina Benth., S. persepolitana Boiss., and S. hydrangea DC. ex Benth. were extracted with dichloromethane. The SEs were analyzed using gas chromatography-mass spectrometry (GC/MS). The antibacterial activity of each extract was assessed against Escherichia coli, Staphylococcus epidermidis, and Bacillus subtilis strains using the agar disc diffusion bioassay. The yields of extracts were in the range from 1.1- 2.3% w/w, while the detected compounds constituted 59.3-95.4% of the total extract composition. All species except S. persepolitana contained the sesquiterpenes, including β-caryophyllene (0.5-19.5%) and germacrene D (0.4-12.9%), while sclareol (2.1-75.6%) was the major labdane diterpenoid in the examined Salvia species excepting S. hydrangea. In addition to terpenoids, the analyzed SEs contained long-chain n-alkanes, fatty acids, alcohols, and aldehydes in the range from 4.8-78.5%. E. coli was the most susceptible microorganism to the tested extracts of S. persepolitana calyxes and stems (20 and 18 mm) and the S. lachnocalyx stems (17 mm), respectively. The antibacterial properties of the SEs of the plants suggested their protective role against pathogenic microorganisms, which can be attributed to their major phytochemicals such as sclareol and abienol.
Abstract
Background and Aims
Salvia is the largest genus within Lamiaceae, with about 980 species currently recognized. East Asia, with approx. 100 species, is one of the three major biodiversity ...centres of Salvia. However, relationships within this lineage remain unclear, and the staminal lever mechanism, which may represent a key innovation within the genus, has been understudied. By using six genetic markers and nearly comprehensive taxon sampling, this study attempts to elucidate relationships and examine evolutionary trends of staminal development within the East Asia (EA) Salvia clade.
Methods
Ninety-one taxa of EA Salvia were sampled and 34 taxa representing all other major lineages of Salvia were included for analysis. Two nuclear internal transcribed spacer (ITS) and external transcribed spacer (ETS) and four chloroplast (psbA–trnH, ycf1–rps15, trnL–trnF and rbcL) DNA markers were used for phylogenetic analysis employing maximum parsimony (MP), maximum likelihood (ML) and BEAST, with the latter also used to estimate divergence times.
Key Results
All Salvia species native to East Asia form a clade, and eight major subclades (A–G) were recognized. Subclade A, comprising two limestone endemics (S. sonchifolia and S. petrophila), is sister to the remainder of EA Salvia. Six distinct stamen types were observed within the EA clade. Stamen type A, with two fully fertile posterior thecae, only occurs in S. sonchifolia and may represent the ancestral stamen type within EA Salvia. Divergence time estimates showed that the crown of EA Salvia began to diversify approx. 17.4 million years ago.
Conclusions
This study supports the adoption of a broadly defined Salvia and treats EA Salvia as a subgenus, Glutinaria, recognizing eight sections within this subgenus. Stamen type A is ostensibly plesiomorphic within EA Salvia, and the other five types may have been derived from it. Staminal morphology has evolved in parallel within the EA Salvia, and staminal structure alone is inadequate to delimit infrageneric categories.
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.
Tanshinones are the bioactive nor-diterpenoid constituents of the Chinese medicinal herb Danshen (Salvia miltiorrhiza). These groups of chemicals have the characteristic furan D-ring, which ...differentiates them from the phenolic abietane-type diterpenoids frequently found in the Lamiaceae family. However, how the 14,16-epoxy is formed has not been elucidated. Here, we report an improved genome assembly of Danshen using a highly homozygous genotype. We identify a cytochrome P450 (CYP71D) tandem gene array through gene expansion analysis. We show that CYP71D373 and CYP71D375 catalyze hydroxylation at carbon-16 (C16) and 14,16-ether (hetero)cyclization to form the D-ring, whereas CYP71D411 catalyzes upstream hydroxylation at C20. In addition, we discover a large biosynthetic gene cluster associated with tanshinone production. Collinearity analysis indicates a more specific origin of tanshinones in Salvia genus. It illustrates the evolutionary origin of abietane-type diterpenoids and those with a furan D-ring in Lamiaceae.
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