ABSTRACT
BACKGROUND: In the past two decades, the impacts of Helium-Neon (He-Ne) laser on stress resistance and secondary metabolism in plants have been studied, but the signaling pathway which by laser regulates this process remains unclear. Therefore, the current study sought to explore the role of RBOH-dependent signaling in He-Ne laser-induced salt tolerance and elicitation of secondary metabolism in Salvia officinalis. Seeds were primed with He-Ne laser (6 J cm- 2) and peroxide hydrogen (H2O2, 5 mM) and 15-old-day plants were exposed to two salinity levels (0, 75 mM NaCl). RESULTS: Salt stress reduced growth parameters, chlorophyll content and relative water content (RWC) and increased malodialdehyde (MDA) and H2O2 contents in leaves of 45-old-day plants. After 48 h of salt exposure, higher transcription levels of RBOH (encoding NADPH oxidase), PAL (phenylalanine ammonia-lyase), and RAS (rosmarinic acid synthase) were recorded in leaves of plants grown from seeds primed with He-Ne laser and/or H2O2. Despite laser up-regulated RBOH gene in the early hours of exposing to salinity, H2O2 and MDA contents were lower in leaves of these plants after 30 days. Seed pretreatment with He-Ne laser and/or H2O2 augmented the accumulation of anthocyanins, total phenol, carnasol, and rosmarinic acid and increased total antioxidant capacity under non-saline and more extensively at saline conditions. Indeed, these treatments improved RWC, and K+/Na+ ratio, enhanced the activities of superoxide dismutase and ascorbate peroxidase and proline accumulation, and significantly decreased membrane injury and H2O2 content in leaves of 45-old-day plants under salt stress. However, applying diphenylene iodonium (DPI as an inhibitor of NADPH oxidase) and N, N-dimethyl thiourea (DMTU as a H2O2 scavenger) after laser priming reversed the aforementioned effects which in turn resulted in the loss of laser-induced salt tolerance and secondary metabolism. CONCLUSIONS: These findings for the first time deciphered that laser can induce a transient RBOH-dependent H2O2 burst, which might act as a downstream signal to promote secondary metabolism and salt stress alleviation in S. officinalis plants.
Subject(s)
Cinnamates , Depsides , Rosmarinic Acid , Salt Tolerance , Salvia officinalis , Signal Transduction , Salvia officinalis/metabolism , Salvia officinalis/physiology , Salvia officinalis/drug effects , Salvia officinalis/genetics , Depsides/metabolism , Cinnamates/metabolism , Abietanes/metabolism , Hydrogen Peroxide/metabolism , Lasers , Plant Proteins/metabolism , Plant Proteins/genetics , Plant Leaves/metabolism , Plant Leaves/drug effects , Gene Expression Regulation, PlantABSTRACT
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.
Subject(s)
Oils, Volatile , Salvia officinalis , Salvia , Salvia officinalis/genetics , Salvia officinalis/metabolism , DNA Copy Number Variations , Monoterpenes/metabolism , Salvia/genetics , Salvia/metabolism , Oils, Volatile/metabolismABSTRACT
Studying the population-genetic and phylogeographic structures of a representative species of a particular geographical region can not only provide us with information regarding its evolutionary history, but also improve our understanding of the evolutionary processes underlying the patterns of species diversity in that area. By analysing eight highly polymorphic microsatellite loci and two chloroplast DNA regions, we have investigated the influence of Pleistocene climate fluctuations on the evolutionary history of Salvia officinalis L. (common sage). The populations with the highest genetic diversity were located in the central parts of the Balkan distribution range. A large group of closely related haplotypes was distributed throughout the Balkans and the central Apennines, while the private lineage occupied the southern Apennines. In addition, two highly differentiated lineages were scattered only over the Balkans. The results suggest that a single refugium of the studied species from the last glacial period was located in the central part of the range in the Balkans. Numerous microrefugia, probably spanning several glaciation cycles, were scattered across the Balkans, while colonisation of the Apennines from the Balkans occurred at least on two occasions.
Subject(s)
Salvia officinalis , Balkan Peninsula , DNA, Chloroplast/genetics , DNA, Mitochondrial/genetics , Genetic Variation , Haplotypes , Microsatellite Repeats/genetics , Phylogeny , Phylogeography , Salvia officinalis/geneticsABSTRACT
Salvia officinalis is one of the most important medicinal and aromatic plants in terms of nutritional and medicinal value because it contains a variety of vital active ingredients. Terpenoid compounds, particularly monoterpenes (C10) and sesquiterpenes, are the most important and abundant among these active substances (C15). Terpenes play a variety of roles and have beneficial biological properties in plants. With these considerations, the current study sought to clone theNAD+-dependent farnesol dehydrogenase (SoFLDH, EC: 1.1.1.354) gene from S. officinalis. Functional analysis revealed that, SoFLDH has an open reading frame of 2,580 base pairs that encodes 860 amino acids.SoFLDH has two conserved domains and four types of highly conserved motifs: YxxxK, RXR, RR (X8) W, TGxxGhaG. However, SoFLDH was cloned from Salvia officinalis leaves and functionally overexpressed in Arabidopsis thaliana to investigate its role in sesquiterpenoid synthases. In comparison to the transgenic plants, the wild-type plants showed a slight delay in growth and flowering formation. To this end, a gas chromatography-mass spectrometry analysis revealed that SoFLDH transgenic plants were responsible for numerous forms of terpene synthesis, particularly sesquiterpene. These results provide a base for further investigation on SoFLDH gene role and elucidating the regulatory mechanisms for sesquiterpene synthesis in S. offcinalis. And our study paves the way for the future metabolic engineering of the biosynthesis of useful terpene compounds in S. offcinalis.
Subject(s)
Alkyl and Aryl Transferases , Arabidopsis , Salvia officinalis , Sesquiterpenes , Alkyl and Aryl Transferases/genetics , Alkyl and Aryl Transferases/metabolism , Arabidopsis/genetics , Arabidopsis/metabolism , Farnesol/metabolism , NAD/metabolism , NAD (+) and NADP (+) Dependent Alcohol Oxidoreductases , Plants, Genetically Modified/metabolism , Salvia officinalis/genetics , Sesquiterpenes/metabolism , Terpenes/metabolismABSTRACT
Enzyme catalysis has emerged as a key technology for developing efficient, sustainable processes in the chemical, biotechnological and pharmaceutical industries. Plants provide large and diverse pools of biosynthetic enzymes that facilitate complex reactions, such as the formation of intricate terpene carbon skeletons, with exquisite specificity. High-resolution structural analysis of these enzymes is crucial in order to understand their mechanisms and modulate their properties by targeted engineering. Although cryo-electron microscopy (cryoEM) has revolutionized structural biology, its applicability to high-resolution structural analysis of comparatively small enzymes has so far been largely unexplored. Here, it is shown that cryoEM can reveal the structures of plant borneol dehydrogenases of â¼120â kDa at or below 2â Å resolution, paving the way for the rapid development of new biocatalysts that can provide access to bioactive terpenes and terpenoids.
Subject(s)
Catalysis , Cryoelectron Microscopy/methods , Enzymes/chemistry , Plants/enzymology , Alcohol Oxidoreductases/chemistry , Models, Molecular , Molecular Structure , Protein Engineering/methods , Salvia/chemistry , Salvia/genetics , Salvia officinalis/chemistry , Salvia officinalis/genetics , Terpenes/chemistryABSTRACT
The individual impact of silicon (Si) and nitric oxide (NO) on secondary metabolism in several plant species has been reported, but their combined effect has never been evaluated yet. Therefore, in this study, single and combined impacts of NO and Si on the biosynthesis of rosmarinic acid (RA) and essential oil (EO) content in leaves of Salvia officinalis were investigated under both non-stress and Cu stress conditions. The results indicated that high Cu concentration decreased biomass and the content of polyphenols, but elevated electrolyte leakage, while lower Cu concentrations, especially 200 µM Cu, increased the content of polyphenols, EO, and antioxidant capacity in leaves of S. officinalis. The foliar application of sodium silicate (1 mM Si) and sodium nitroprusside (200 µM SNP as a NO donor) alone and particularly in combination improved shoot dry biomass, restored chlorophyll and carotenoids, increased EO content, the amounts of flavonoids, and phenolic compounds especially RA, and enhanced antioxidant capacity in the leaves of S. officinalis under both non-stress and Cu stress conditions. Copper treatment increased NO content, upregulated expression of PAL, TAT, and RAS genes, and enhanced phenylalanine ammonia-lyase activity in the leaves, which were responsible for improving the production of phenolic compounds, particularly rosmarinic acid. Foliar spraying with Si and SNP intensified these attributes. All responses were more pronounced when NO and Si were simultaneously applied under Cu stress. These findings suggest that NO and Si synergistically modulate secondary metabolism through upregulation of related gene expression and enzyme activities under both non-stress and Cu stress conditions.
Subject(s)
Oils, Volatile , Salvia officinalis , Antioxidants/metabolism , Cinnamates , Depsides , Nitric Oxide/metabolism , Oils, Volatile/metabolism , Oils, Volatile/pharmacology , Polyphenols/metabolism , Salvia officinalis/genetics , Salvia officinalis/metabolism , Silicon , Rosmarinic AcidABSTRACT
To study the effects of foliar application of putrescine (distilled water (0), 0.75, 1.5, and 2.25 mM) and water deficit stress (20%, 40%, 60%, and 80% available soil water depletion (ASWD)) on the physiological, biochemical, and molecular attributes of Salvia officinalis L., a factorial experiment was performed in a completely randomized design with three replications in the growth chamber. The results of Real-Time quantitative polymerase chain reaction (qRT-PCR) analysis showed that putrescine concentration, irrigation regime, and the two-way interaction between irrigation regime and putrescine concentration significantly influenced cineole synthase (CS), sabinene synthase (SS), and bornyl diphosphate synthase (BPPS) relative expression. The highest concentration of 1,8-cineole, camphor, α-thujone, ß-thujone, CS, SS, and BPPS were obtained in the irrigation regime of 80% ASWD with the application of 0.75 mM putrescine. There was high correlation between expression levels of the main monoterpenes synthase and the concentration of main monoterpenes. The observed correlation between the two enzyme activities of ascorbate peroxidase (APX) and catalase (CAT) strongly suggests they have coordinated action. On the other hand, the highest peroxidase (PO) and superoxide dismutase (SOD) concentrations were obtained with the application of 0.75 mM putrescine under the irrigation regime of 40% ASWD. Putrescine showed a significant increase in LAI and RWC under water deficit stress. There was an increasing trend in endogenous putrescine when putrescine concentration was increased in all irrigation regimes. Overall, the results suggest that putrescine may act directly as a stress-protecting compound and reduced H2O2 to moderate the capacity of the antioxidative system, maintain the membrane stability, and increase secondary metabolites under water deficit stress.
Subject(s)
Putrescine/metabolism , Salvia officinalis/physiology , Stress, Physiological , Water , Gene Expression Regulation, Plant , Salvia officinalis/genetics , Salvia officinalis/metabolism , Terpenes/metabolismABSTRACT
The induction of polyploidy is an efficient technique for creating a diversity of genetic, phenotypic, and phytochemical novelties in plant taxa. Sage (Salvia officinalis L.) is a well-known medicinal plant rich of valuable bioactive molecules such as triterpenic and phenolic acids. In the present study, the effect of in vitro and in vivo polyploidization on morphological characteristics, anatomical structures, phytochemical traits, and expression level of the genes involved in the biosynthesis of major triterpenic acids (ursolic, betulinic, and oleanolic acids) of the plant was studied. The sterile seeds treated with different concentrations (0, 0.05, 0.1, and 0.2%) of colchicine for 24 and 48â¯h were considered for polyploidy induction. Flow cytometry and chromosome counting were used to confirm the ploidy level of diploid (2nâ¯=â¯2xâ¯=â¯14, 2C DNAâ¯=â¯1.10 pg) and tetraploid (2nâ¯=â¯4xâ¯=â¯28, 2C DNAâ¯=â¯2.12 pg) plants after seven months. The highest polyploidy induction was obtained by applying 0.1% (w/v) colchicine for 48â¯h with an efficiency of 19.05% in vitro tetraploidy. Polyploids showed differences in leaf shape and color, leaf and stem thickness, trichrome density, root length, plant height, and number of leaves compared to diploid plants. There was also a significant decrease in rosmarinic acid content in polyploid (plants) as compared to diploid plants. Although a significant decrease in ursolic acid content was observed in polyploids, betulinic acid content associated with the expression levels of genes encoding enzymes being active in triterpene biosynthesis such as squalene epoxidase (SQE) and lupeol synthase (LUS). The expression of SQE and LUS was significantly increased in in vitro tertaploids (2.9-fold) and in vivo mixoploids (2.4-fold). The results confirm the idea that induced polyploidy can randomly alter breeding traits of plants as well as the content of bioactive compounds.
Subject(s)
Plants, Medicinal , Salvia officinalis , Plant Leaves , Polyploidy , Salvia officinalis/genetics , TetraploidyABSTRACT
Rosemary and sage species from Lamiaceae contain high amounts of structurally related but diverse abietane diterpenes. A number of substances from this compound family have potential pharmacological activities and are used in the food and cosmetic industry. This has raised interest in their biosynthesis. Investigations in Rosmarinus officinalis and some sage species have uncovered two main groups of cytochrome P450 oxygenases that are involved in the oxidation of the precursor abietatriene. CYP76AHs produce ferruginol and 11-hydroxyferruginol, while CYP76AKs catalyze oxidations at the C20 position. Using a modular Golden-Gate-compatible assembly system for yeast expression, these enzymes were systematically tested either alone or in combination. A total of 14 abietane diterpenes could be detected, 8 of which have not been reported thus far. We demonstrate here that yeast is a valid system for engineering and reconstituting the abietane diterpene network, allowing for the discovery of novel compounds with potential bioactivity.
Subject(s)
Abietanes/metabolism , Cytochrome P-450 Enzyme System/metabolism , Rosmarinus/metabolism , Saccharomyces cerevisiae/metabolism , Salvia officinalis/chemistry , Salvia officinalis/metabolism , Abietanes/chemistry , Cytochrome P-450 Enzyme System/genetics , Molecular Structure , Oxidation-Reduction , Rosmarinus/chemistry , Saccharomyces cerevisiae/genetics , Salvia officinalis/geneticsABSTRACT
The inheritance of phenotypic, genetic and epigenetic traits in hybridization events is difficult to predict, as numerous evolutionary, ecological, and genetic factors can play a crucial role in the process of hybridization. In the middle Adriatic island of Vis, we investigated hybridization between Salvia officinalis and S. fruticosa at morphological, genetic and epigenetic levels. SSR results revealed that hybrid individuals were characterized by diploid set of chromosomes suggesting homoploid hybridization. A well-defined group that mostly comprised of F1 generation individuals was detected. For the majority of analysed morphological characteristics, hybrids were placed in-between parental taxa, while at the same time, values of different genetic parameters were mostly higher in hybrids than in parental species. The results revealed a high contrast in the levels of phenotypic variability and epigenetic excitation between parental taxa. Environmental niche modelling confirmed that in the studied location S. officinalis experiences optimal climatological conditions, while S. fruticosa struggles with unsuitable conditions. Very low levels of gene flow between the parental species were detected. In addition, contrasting levels of epigenetic excitation in the studied groups clearly demonstrated the importance of an epigenetic response to an altered environment and confirmed the trans-generational nature of the epigenetic changes.
Subject(s)
Chimera/genetics , Epigenesis, Genetic , Gene Expression Regulation , Models, Genetic , Salvia officinalis/geneticsABSTRACT
Tropospheric ozone (O3) is the most important gaseous pollutant and induces a mass of negative impacts on vegetation at functional and genic levels. The aim of the present study was to investigate the role of reactive oxygen species and signalling molecules in sage plants exposed to O3 (200â¯ppb, 5â¯h). Ozone exposure induced only a transient oxidative burst, as confirmed by the rapid peak of anion superoxide during the first hours of exposure (+16% compared to controls). The spontaneous reaction of O3 with membrane fatty acids stimulates peroxidative processes, as demonstrated by the rise of thiobarbituric acid reactive substances concentration starting after 1â¯h of exposure (+25%). The formation of lipid-based signalling molecules (e.g. jasmonic acid) may be regarded as a sort of O3-perception. The concomitant accumulation of salicylic acid suggests that sage responds early to O3 by inducing cellular antioxidants mechanisms in order to minimize O3-oxidative burst. The transient increase of abscisic acid (+25% at the end of the treatment) twinned with the maximal ethylene emission (about two-fold higher than controls) could be interpreted as a first attempt by plants to regulate the signalling responses induced by O3. In order to investigate the involvement of transcription factors in managing oxidative protection, BLASTX analysis against the Salvia miltiorrhiza sequence genome was carried out using Arabidopsis thaliana WRKY sequences as queries. Six gene sequences were identified for sage WRKYs and their relative gene expression analyses were characterized. WRKY4, WRKY5, WRKY11 and WRKY46 were up-regulated by O3 at 2 and 5â¯h of exposure and they showed similarity with AtWRKY48, AtWRKY22 and AtWRKY53 in A. thaliana. These results suggest that WRKYs could play a pivotal role in the signalling mechanisms during the responses of plants to O3.
Subject(s)
Oxidative Stress/drug effects , Ozone/metabolism , Plant Growth Regulators/biosynthesis , Respiratory Burst/drug effects , Salvia officinalis/physiology , Signal Transduction/drug effects , Arabidopsis Proteins/metabolism , Salvia officinalis/drug effects , Salvia officinalis/genetics , Signal Transduction/genetics , Transcription Factors/metabolismABSTRACT
Taxadiene synthase (TXS) catalyzes the formation of natural product taxa-4(5),11(12)-diene (henceforth taxadiene). Taxadiene is the precursor in the formation of Taxol, which is an important natural anticancer agent. In the current study, we present a detailed mechanistic view of the biosynthesis of taxadiene by TXS using a hybrid quantum mechanics-molecular mechanics potential in conjunction with free energy simulation methods. The obtained free-energy landscape displays initial endergonic steps followed by a stepwise downhill profile, which is an emerging free-energy fingerprint for type I terpene synthases. We identify an active-site Trp residue (W753) as a key feature of the TXS active-site architecture and propose that this residue stabilized intermediate cations via π-cation interactions. To validate our proposed active TXS model, we examine a previously reported W753H mutation, which leads to the exclusive formation of side product cembrene A. The simulations of the W753H mutant show that, in the mutant structure, the His side chain is in the perfect position to deprotonate the cembrenyl cation en route to cembrene formation and that this abortive deprotonation is an energetically facile process. On the basis of the current model, we propose that an analogous mutation of Y841 to His could possibly lead to verticillane. The current simulations stress the importance of the precise positioning of key active-site residues in stabilizing intermediate carbocations. In view of the great pharmaceutical importance of taxadiene, a detailed understanding of the TXS mechanism can provide important clues toward a synthetic strategy for Taxol manufacturing.
Subject(s)
Alkenes/metabolism , Diterpenes/metabolism , Isomerases/metabolism , Plant Proteins/metabolism , Salvia officinalis/metabolism , Biosynthetic Pathways , Catalytic Domain , Isomerases/chemistry , Isomerases/genetics , Models, Molecular , Plant Proteins/chemistry , Plant Proteins/genetics , Point Mutation , Protein Conformation , Salvia officinalis/chemistry , Salvia officinalis/enzymology , Salvia officinalis/genetics , ThermodynamicsABSTRACT
Quality control of drugs consists of identifying the raw material to avoid unwanted admixtures or exchange of material as well as looking for abiotic and biotic contaminations. So far, identity and microbial contamination are analyzed by separate processes and separate methods. Species identification by their DNA ("DNA barcoding") has the potential to supplement existing methods of identification. The introduction of next-generation sequencing methods offers completely new approaches like the identification of whole communities in one analysis, termed "DNA metabarcoding". Here we present a next-generation sequencing assessment to identify plants and fungi of two commercial sage samples (Salvia officinalis) using the standard DNA barcoding region "internal transcribed spacer" consisting of internal transcribed spacer 1 and internal transcribed spacer 2, respectively. The main species in both samples was identified as S. officinalis. The spectrum of accompanying plant and fungal species, however, was completely different between the samples. Additionally, the composition between internal transcribed spacer 1 and internal transcribed spacer 2 within the samples was different and demonstrated the influence of primer selection and therefore the need for harmonization. This next-generation sequencing approach does not result in quantitative species composition but gives deeper insight into the composition of additional species. Therefore, it would allow for a better knowledge-based risk assessment than any other method available. However, the method is only economically feasible in routine analysis if a high sample throughput can be guaranteed.
Subject(s)
DNA Barcoding, Taxonomic/methods , Salvia officinalis/genetics , DNA, Plant/genetics , Drug Contamination , High-Throughput Nucleotide Sequencing/methods , Polymerase Chain Reaction/methods , Quality Control , Salvia officinalis/microbiologyABSTRACT
A large number of terpenoid compounds have been extracted from different tissues of S. officinalis. However, the molecular genetic basis of terpene biosynthesis pathways is virtually unknown. In this study, approximately 6.6 Gb of raw data were generated from the transcriptome of S. officinalis leaves using Illumina HiSeq 2000 sequencing. After filtering and removing the adapter sequences from the raw data, the number of reads reached 21 million, comprising 98 million of high-quality nucleotide bases. 48,671 unigenes were assembled de novo and annotated for establishing a valid database for studying terpenoid biosynthesis. We identified 135 unigenes that are putatively involved in terpenoid metabolism, including 70 mevalonate and methyl-erythritol phosphate pathways, terpenoid backbone biosynthesis genes, and 65 terpene synthase genes. Moreover, five terpene synthase genes were studied for their functions in terpenoid biosynthesis by using transgenic tobacco; most transgenic tobacco plants expressing these terpene synthetic genes produced increased amounts of terpenoids compared with wild-type control. The combined data analyses from the transcriptome and metabolome provide new insights into our understanding of the complex metabolic genes in terpenoid-rich sage, and our study paves the way for the future metabolic engineering of the biosynthesis of useful terpene compounds in S. officinalis.
Subject(s)
Biosynthetic Pathways/genetics , Genes, Plant , Metabolomics , Salvia officinalis/genetics , Salvia officinalis/metabolism , Terpenes/metabolism , Transcriptome/genetics , Alkyl and Aryl Transferases/genetics , Alkyl and Aryl Transferases/metabolism , Gene Expression Regulation, Plant , Microsatellite Repeats/genetics , Molecular Sequence Annotation , Oils, Volatile/analysis , Phylogeny , Plant Leaves/genetics , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reproducibility of Results , Nicotiana/genetics , VolatilizationABSTRACT
In previous experiments, we demonstrated that the amount of monoterpenes in sage is increased massively by drought stress. Our current study is aimed to elucidate whether this increase is due, at least in part, to elevated activity of the monoterpene synthases responsible for the biosynthesis of essential oils in sage. Accordingly, the transcription rates of the monoterpene synthases were analyzed. Salvia officinalis plants were cultivated under moderate drought stress. The concentrations of monoterpenes as well as the expression of the monoterpene synthases were analyzed. The amount of monoterpenes massively increased in response to drought stress; it doubled after just two days of drought stress. The observed changes in monoterpene content mostly match with the patterns of monoterpene synthase expressions. The expression of bornyl diphosphate synthase was strongly up-regulated; its maximum level was reached after two days. Sabinene synthase increased gradually and reached a maximum after two weeks. In contrast, the transcript level of cineole synthase continuously declined. This study revealed that the stress related increase of biosynthesis is not only due to a "passive" shift caused by the stress related over-reduced status, but also is due - at least in part-to an "active" up-regulation of the enzymes involved.
Subject(s)
Droughts , Intramolecular Lyases/metabolism , Salvia officinalis/enzymology , Stress, Physiological , Gene Expression Regulation, Plant , Intramolecular Lyases/genetics , Monoterpenes/metabolism , Oils, Volatile/metabolism , Salvia officinalis/genetics , Up-RegulationABSTRACT
MAIN CONCLUSION: As a result of this work, we were able to characterize seven indigenous to Greece Salvia officinalis populations using genetic and metabolomic tools. These tools can be used to select the most promising genotypes, capable to design future breeding programs for high valuable varieties. An initial investigation was carried out to compare the genetic and metabolic diversity in S. officinalis grown in Greece and to discern the relationship between the two sets of data. Analysis of inter-simple sequence repeats (ISSR) revealed significant genetic differences among seven sage populations, which were grouped into three main clusters according to an UPGMA ISSR data-based dendrogram and Principle Coordinate Analysis. 80 loci were scored of which up to 90% were polymorphic at species level. According to the composition of their essential oil, the populations were classified into two chemotypes: 1.8 cineole/α-thujone and α-thujone/1.8 cineole. Additionally, a targeted ultra performance liquid chromatography (UPLC-MS/MS) method was used to qualify and quantify phenolic compounds in methanolic extracts of the seven sage genotypes according to which they were districted in six clusters among the sage populations. The main compounds characterizing the seven genotypes were rosmarinic acid and carnosol, followed by apigenin-7-O-glucoside (Ap7glc), and luteolin-7-O-glucoside (Lu7glc). The correlation between matrices obtained from ISSR data and metabolic profiles was non-significant. However, based on the differences in metabolic fingerprint, we aimed to define populations using as main selection criteria the high polyphenol content and desired essential oil composition, using state to the art analytical tools for the identification of parent lines for breeding programs.
Subject(s)
Genetic Variation , Metabolome , Oils, Volatile/classification , Polyphenols/metabolism , Salvia officinalis/genetics , Bicyclic Monoterpenes , Breeding , Cyclohexanols/classification , Cyclohexanols/metabolism , Eucalyptol , Flavones/classification , Flavones/metabolism , Genetics, Population , Genotype , Glucosides/classification , Glucosides/metabolism , Monoterpenes/classification , Monoterpenes/metabolism , Oils, Volatile/metabolism , Phylogeny , Plant Leaves/genetics , Plant Leaves/metabolism , Salvia officinalis/metabolismABSTRACT
Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1) the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2) species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight into genetic diversity and structure also provide the baseline data for conservation of S. officinalis genetic resources valuable for future breeding programmes.
Subject(s)
Agriculture , Genetic Variation , Salvia officinalis/growth & development , Salvia officinalis/genetics , Balkan Peninsula , Ecosystem , Genetics, Population , Geography , Microsatellite Repeats/genetics , Population DynamicsABSTRACT
Partial fragments of phenylalanine ammonia lyase (PAL) genes were cloned and characterized from Salvia officinalis (SoPAL) and Salvia virgata (SvPAL). Different concentrations (250 and 500 µM) of exogenous salicylic acid (SA) were used when correlation between PAL expression and rosmarinic acid (RA) accumulation was compared. The results showed that the deduced cDNA sequences of the partial genes had high similarities with those of known PAL gene from other plant species. Semi-quantitative reverse transcription PCR (RT-PCR) analysis revealed that exogenous application of SA led to up-regulating of the PAL expression. Further analysis showed that in S. virgata, at higher concentration of SA, higher accumulation of RA was achieved, while in S. officinalis, the higher RA accumulation was observed at lower concentration of SA. It was concluded that there was no positive correlation between the intensity of PAL transcription and the RA accumulation in the studied species. Therefore, despite of the increase in transcription rate of the PAL at the higher concentration of SA, the lower amounts of RA were accumulated in the case of S. officinalis. Consequently, the hypothesis that PAL is the rate-determining step in RA biosynthesis is not always valid and probably some other unknown factors participate in the synthesis of phenolics.
Subject(s)
Cinnamates/metabolism , Depsides/metabolism , Gene Expression Regulation, Plant/drug effects , Phenylalanine Ammonia-Lyase/genetics , Plant Shoots/genetics , Salicylic Acid/pharmacology , Salvia officinalis/drug effects , Salvia officinalis/genetics , Cloning, Molecular , Plant Shoots/drug effects , Salvia officinalis/metabolism , Salvia officinalis/physiology , Stress, Physiological/drug effects , Stress, Physiological/genetics , Rosmarinic AcidABSTRACT
Salvia officinalis is used as a dietary supplement with diverse medicinal activity (e.g. antidiabetic and antiatherosclerotic effects). The plant also exerts profound cytotoxicity toward cancer cells. Here, we investigated possible modes of action to explain its activity toward drug-resistant tumor cells. Log10IC50 values of two constituents of S. officinalis (ursolic acid, pomolic acid) were correlated to the expression of ATP-binding cassette (ABC) transporters (P-glycoprotein/ABCB1/MDR1, MRP1/ABCC1, BCRP/ABCG2) and epidermal growth factor receptor (EGFR) or mutations in RAS oncogenes and the tumor suppressor gene TP53 of the NCI panel of cell lines. Gene expression profiles predicting sensitivity and resistance of tumor cells to these compounds were determined by microarray-based mRNA expressions, COMPARE, and hierarchical cluster analyses. Furthermore, the binding of both plant acids to key molecules of the NF-κB pathway (NF-κB, I-κB, NEMO) was analyzed by molecular docking. Neither expression nor mutation of ABC transporters, oncogenes, or tumor suppressor genes correlated with log10IC50 values for ursolic acid or pomolic acid. In microarray analyses, many genes involved in signal transduction processes correlated with cellular responsiveness to these compounds. Molecular docking indicated that the two plant acids strongly bound to target proteins of the NF-κB pathway with even lower free binding energies than the known NF-κB inhibitor MG-132. They interacted more strongly with DNA-bound NF-κB than free NF-κB, pointing to inhibition of DNA binding by these compounds. In conclusion, the lack of cross-resistance to classical drug resistance mechanisms (ABC-transporters, oncogenes, tumor suppressors) may indicate a promising role of the both plant acids for cancer chemotherapy. Genes involved in signal transduction may contribute to the sensitivity or resistance of tumor cells to ursolic and pomolic acids. Ursolic and pomolic acid may target different steps of the NF-κB pathway to inhibit NF-κB-mediated functions.
Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Oleanolic Acid/analogs & derivatives , Plants, Medicinal/chemistry , Salvia officinalis/chemistry , Triterpenes/isolation & purification , Triterpenes/pharmacology , ATP Binding Cassette Transporter, Subfamily B/metabolism , ATP-Binding Cassette Transporters/metabolism , Antineoplastic Agents, Phytogenic/chemistry , Breast Neoplasms/metabolism , Drug Resistance, Neoplasm/drug effects , Genes, erbB-1 , Humans , Leupeptins , Molecular Structure , NF-kappa B/metabolism , Oleanolic Acid/chemistry , Oleanolic Acid/isolation & purification , Oleanolic Acid/pharmacology , Pharmacogenetics , Plants, Medicinal/genetics , Salvia officinalis/genetics , Signal Transduction/drug effects , Triterpenes/chemistry , Ursolic AcidABSTRACT
Nine new microsatellite markers (SSR) were isolated from Salvia officinalis L. A total of 125 alleles, with 8 to 21 alleles per locus, were detected in a natural population from the east Adriatic coast. The observed heterozygosity, expected heterozygosity, and polymorphic information content ranged from 0.46 to 0.83, 0.73 to 0.93 and 0.70 to 0.92, respectively. New microsatellite markers, as well as previously published markers, were tested for cross-amplification in Salvia brachyodon Vandas, a narrow endemic species known to be present in only two localities on the Balkan Peninsula. Out of 30 microsatellite markers tested on the natural S. brachyodon population, 15 were successfully amplified. To obtain evidence of recent bottleneck events in the populations of both species, observed genetic diversity (H(E)) was compared to the expected genetic diversity at mutation-drift equilibrium (H(EQ)) and calculated from the observed number of alleles using a two-phased mutation model (TPM). Recent bottleneck events were detected only in the S. brachyodon population. This result suggests the need to reconsider the current threat category of this endemic species.