Seasonal influence on gene expression of monoterpene synthases in Salvia officinalis (Lamiaceae)

Water stress modulates terpene biosynthesis and morphophysiology at different ploidal levels in Lippia alba (Mill.) N. E. Brown (Verbenaceae)

Monoterpenes are the main component in essential oils of Lippia alba. In this species, the chemical composition of essential oils varies with genome size: citral (geraniol and neral) is dominant in diploids and tetraploids, and linalool in triploids. Because environmental stress impacts various metabolic pathways, we hypothesized that stress responses in L. alba could alter the relationship between genome size and essential oil composition. Water stress affects the flowering, production, and reproduction of plants. Here, we evaluated the effect of water stress on morphophysiology, essential oil production, and the expression of genes related to monoterpene synthesis in diploid, triploid, and tetraploid accessions of L. alba cultivated in vitro for 40 days. First, using transcriptome data, we performed de novo gene assembly and identified orthologous genes using phylogenetic and clustering-based approaches. The expression of candidate genes related to terpene biosynthesis was estimated by real-time quantitative PCR. Next, we assessed the expression of these genes under water stress conditions, whereby 1% PEG-4000 was added to MS medium. Water stress modulated L. alba morphophysiology at all ploidal levels. Gene expression and essential oil production were affected in triploid accessions. Polyploid accessions showed greater growth and metabolic tolerance under stress compared to diploids. These results confirm the complex regulation of metabolic pathways such as the production of essential oils in polyploid genomes. In addition, they highlight aspects of genotype and environment interactions, which may be important for the conservation of tropical biodiversity.

Effect of Different Genotypes and Harvest Times of Sage (Salvia spp. Labiatae) on Lipid Oxidation of Cooked Meat

Lipid oxidation is the primary non-microbial reason for quality deterioration of meat and meat products. Lipid oxidation can be prevented or delayed by antioxidants. In this study, 15 sage (Salvia spp. Labiatae) extracts (five genotypes, three harvest times) were tested for their ability to reduce lipid oxidation (peroxide value (PV) and thiobarbituric acid reactive substances (TBARS)) in ground, uncured, cooked porcine and bovine meat (60%/40% mixture) during 14 days of refrigerated storage. Additionally, total phenolic content was determined, and the antioxidant capacity of the extracts was measured as radical scavenging activity (2,2-diphenyl-1-picrylhydrazyl assay), reducing power, and superoxide anion scavenging activity. All 15 sage extracts were able to reduce lipid oxidation, though showing expected differences depending on genotype and harvest time. The extracts of S. officinalis accession from Foggia, Italy performed better than the other genotypes when looking at the entire storage period and considering both PV and TBARS. Of the applied methods for determining antioxidant capacity, superoxide anion scavenging activity proved to be the best determinant of the ability of sage to reduce lipid oxidation in the meat sample.

Monoterpene synthases of three closely related sage species (Salvia officinalis, S. fruticosa and S. pomifera, Lamiaceae)

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.

Lamiaceae Essential Oils, Phytochemical Profile, Antioxidant, and Biological Activities

Medicinal and aromatic plants present important active compounds that have potential for use in food, pharmaceutical, and agriculture industries. In this sense, the present work aimed to conduct a literature review on the potential applications of essential oils from Lamiaceae species. Antioxidant, anti-inflammatory, and antimicrobial activities were evaluated. The importance of this study is demonstrated as a way to theoretically provide information on the use of different plants belonging to the Lamiaceae family, especially with regard to the physical, chemical, and biological properties of its essential oils.

Improving water deficit tolerance of Salvia officinalis L. using putrescine

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, β-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.

Water deficit stress responses of monoterpenes and sesquiterpenes in different Iranian cultivars of basil

Ocimum basilicum, a popular aromatic plant, contains aromatic terpenes of terpenoids with in vivo and in vitro verified cytotoxicity. Considering the characteristics and potential of its utilization, it would be attractive to reveal its regulation and biosynthesis, originally at the molecular level under water deficit stress. For this aim, for the first time, the gene encoding the enzyme involved in the end step of the MEP biosynthetic pathways (HDR) was cloned, and the accumulation ratio of linalool, germacrene D and γ-cadinene compounds as well as the expression trait of four critical genes (i.e., HDR, LinS, GerS, and GadS) was assessed under water deficit stress in three Iranian cultivars of basil. The highest value of linalool and γ-cadinene were detected for Cultivar 1 (Cult. 1) under mild stress (W1; 52.6 and 21.1%), while insignificant amounts were obtained for Cultivar 3 (Cult. 3). The germacrene D level of Cultivar 2 (Cult. 2) increased under severe and moderate water stresses as compared with mild water deficit stress. Apart from some expectation, all the studied genes demonstrated divergent transcription ratios under water deficit stress. Principal component analyses (PCA) showed that the relative water content (RWC) and HDR gene expression correlated significantly with essential oil components and gene expression in Cult. 1 and 2, which could represent an elevated demand for corresponding metabolites in the plant tissues. The present work elaborates on the regulation of the mentioned genes, and the results indicate that the production of terpenoids might be a drought stress-dependent and cultivar-dependent procedure.

Phytochemicals for Improving Aspects of Cognitive Function and Psychological State Potentially Relevant to Sports Performance

Subjective alertness and optimal cognitive function, including in terms of attention, spatial/working memory and executive function, are intrinsic to peak performance in many sports. Consumption of a number of plant-derived 'secondary metabolite' phytochemicals can modulate these psychological parameters, although there is a paucity of evidence collected in a sporting context. The structural groups into which these phytochemicals fall-phenolics, terpenes and alkaloids-vary in terms of the ecological roles they play for the plant, their toxicity and the extent to which they exert direct effects on brain function. The phenolics, including polyphenols, play protective roles in the plant, and represent a natural, benign component of the human diet. Increased consumption has been shown to improve cardiovascular function and is associated with long-term brain health. However, whilst short-term supplementation with polyphenols has been shown to consistently modulate cerebral blood-flow parameters, evidence of direct effects on cognitive function and alertness/arousal is currently comparatively weak. Terpenes play both attractant and deterrent roles in the plant, and typically occur less frequently in the diet. Single doses of volatile monoterpenes derived from edible herbs such as sage (Salvia officinalis/lavandulaefolia) and peppermint (Mentha piperita), diterpene-rich Ginkgo biloba extracts and triterpene-containing extracts from plants such as ginseng (Panax ginseng/quinquefolius) and Bacopa monnieri have all been shown to enhance relevant aspects of cognitive function and alertness. The alkaloids play toxic defensive roles in the plant, including via interference with herbivore brain function. Whilst most alkaloids are inappropriate in a sporting context due to toxicity and legal status, evidence suggests that single doses of nicotine and caffeine may be able to enhance relevant aspects of cognitive function and/or alertness. However, their benefits may be confounded by habituation and withdrawal effects in the longer term. The efficacy of volatile terpenes, triterpene-rich extracts and products combining low doses of caffeine with other phytochemicals deserves more research attention.

De novo transcriptome sequencing and metabolite profiling analyses reveal the complex metabolic genes involved in the terpenoid biosynthesis in Blue Anise Sage (Salvia guaranitica L.)

Many terpenoid compounds have been extracted from different tissues of Salvia guaranitica. However, the molecular genetic basis of terpene biosynthesis pathways is virtually unknown. In this study, approximately 4 Gb of raw data were generated from the transcriptome of S. guaranitica leaves using Illumina HiSeq 2000 sequencing. After filtering and removing the adapter sequences from the raw data, the number of reads reached 32 million, comprising 186 million of high-quality nucleotide bases. A total of 61,400 unigenes were assembled de novo and annotated for establishing a valid database for studying terpenoid biosynthesis. We identified 267 unigenes that are putatively involved in terpenoid metabolism (including, 198 mevalonate and methyl-erythritol phosphate (MEP) pathways, terpenoid backbone biosynthesis genes and 69 terpene synthases genes). Moreover, three terpene synthase genes were studied for their functions in terpenoid biosynthesis by using transgenic Arabidopsis; most transgenic Arabidopsis 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 blue anise sage, and our study paves the way for the future metabolic engineering of the biosynthesis of useful terpene compounds in S. guaranitica.

Transcriptome and metabolite analyses reveal the complex metabolic genes involved in volatile terpenoid biosynthesis in garden sage (Salvia officinalis)

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.

Water deficit stress fluctuates expression profiles of 4Cl, C3H, COMT, CVOMT and EOMT genes involved in the biosynthetic pathway of volatile phenylpropanoids alongside accumulation of methylchavicol and methyleugenol in different Iranian cultivars of basil

Here, for the first time, the accumulation ratio of methylchavicol and methyleugenoland compounds together with the expression profiles of five critical genes (i.e., 4Cl, C3H, COMT, CVOMT and EOMT) in three Iranian cultivars of basil were assessed under water deficit stress at flowering stage. The highest value of methylchavicol was detected for Cul. 3 under severe stress (S3; 7.695μg/mg) alongside Cul. 2 under similar circumstances (S3; 4.133μg/mg), while regarding Cul. 1, no detectable amounts were acquired. Considering methyleugenol, Cul. 3 (0.396μg/mg; S0) followed by Cul. 1 (S3; 0.160μg/mg) were the capable plant samples in producing some detectable amounts of methyleugenol. Apart from some expectations, all the genes under study exhibited also different transcription ratios under deficit stress. Our results, overall, demonstrated that the regulation of the above-mentioned genes and production of methychavicol and methyleugenol seems to be a cultivar- and drought stress-dependent mechanism.

Impact of drought stress on specialised metabolism: Biosynthesis and the expression of monoterpene synthases in sage (Salvia officinalis)

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.

Scent from Jasminum grandiflorum flowers: Investigation of the change in linalool enantiomers at various developmental stages using chemical and molecular methods

Jasminum species are among the most preferred fresh cut flowers in India since ancient times. The plant produces small and fragrant flowers, which are of great demand in the preparation of fragrant garlands and also in perfume industries. Floral volatile of Jasminum grandiflorum L. (Family: Oleaceae) was extracted using solid-phase microextraction and analyzed in enantioselective gas chromatography. Chemical classes of identified volatiles revealed the presence of terpenoids, phenylpropanoids, and fatty acid derivatives. Marker constituent of flower volatiles, linalool was selected for analytical characterization on ethyl- and acetyl-β-cyclodextrin stationary phase. (R)-(-)-Linalool was found as major enantiomer in volatiles of floral buds whereas (S)-(+)-linalool predominated in the volatiles of matured flowers. Simultaneously, a quantitative real-time PCR was performed to find the gene expression of linalool synthase to investigate the mechanism of enantiomeric inversion. The emission pattern of (R)-(-)-linalool at different flower developmental stages was well correlated (P = 0.01) with the gene expression of the cloned linalool synthase from J. grandiflorum. We observed that the successive change in (R)- to (S)-linalool ratio from bud to mature flower was mainly due to the enantio- specific transformation and temporal decline of (R)-linalool producing gene in J. grandiflorum. This enantiomeric change also leads to the difference in flower aroma. Furthermore, this is probably the reason behind consumer's acceptance for jasmine buds rather than bloomed flowers in cut flower segments.

Tissue-specific gene-expression patterns of genes associated with thymol/carvacrol biosynthesis in thyme (Thymus vulgaris L.) and their differential changes upon treatment with abiotic elicitors

Thyme (Thymus vulgaris L.) is known to produce a variety of phenolic monoterpenes such as thymol and carvacrol. Thymol and carvacrol are health-promoting, biocide and antitoxin compounds and have been considered as the main constituents of essential oils in T. vulgaris. To improve our understanding of the regulation of monoterpene biosynthesis in thyme, the expression of genes related to thymol and carvacrol biosynthesis in different tissues and in response to abiotic elicitors was analyzed. Methyl jasmonate (MeJA), salicylic acid (SA), trans-cinnamic acid (tCA) and UV-C irradiation were applied to T. vulgare leaves and transcript levels of early (DXR) and late (TvTPS1, CYP71D178 and CYP71D180) biosynthetic genes of thymol and carvacrol were measured. The results showed that early step and late step genes in thymol/carvacrol biosynthesis are differentially regulated. DXR was not found to be exclusively expressed in glandular trichomes; in contrast, biosynthetic genes including γ-terpinene synthase (TvTPS1) and two cytochrome P450s, CYP71D178 and CYP71D180, were preferentially expressed in glandular secretory trichomes. The high expression of late biosynthetic genes in glandular trichomes, which also contain the highest concentration of thymol and carvacrol, suggests that glandular trichomes are the structure in which thymol/carvacrol biosynthesis and accumulation occur. Our results indicate that in addition to abiotic elicitors, developmental and spatial factors also play a key role in the biosynthesis of thymol and carvacrol, most likely relating to glandular trichome density and/or activity. Hence optimization of these factors could be considered as a useful strategy to achieve high yield of valuable compounds in T. vulgare or other closely related plant species.

Essential Oil of Thymus munbyanus subsp. coloratus from Algeria: Chemotypification and in vitro Biological Activities

Thymus munbyanus subsp. coloratus (Lamiaceae) is a small shrub endemic to Algeria and Morocco where is found in lawns, rockeries and mountainous regions. From a phytochemical point of view this taxon has never been characterized. In this work we have analysed the chemical compositions of the essential oils obtained from inflorescences and vegetative parts by GC/MS. A new chemotype, i.e. borneol-chemotype, was characterized for the first time in the species. Furthermore, we assessed the biological activities of essential oils, namely the antioxidant, antimicrobial and cytotoxicity on tumor cells that were evaluated by the DPPH, ABTS, and FRAP, disc diffusion, and MTT methods, respectively. Biological assays highlighted a moderate inhibitory effect on Staphylococcus aureus, Escherichia coli and Candida albicans (inhibition zone diameter in the range 9 - 10 mm), and noteworthy cytotoxicity on A375 human melanoma cells (IC₅₀ of 46.95 μg/ml).

Transcriptome Sequencing Analysis Reveals a Difference in Monoterpene Biosynthesis between Scented Lilium 'Siberia' and Unscented Lilium 'Novano'

Lilium is a world famous fragrant bulb flower with high ornamental and economic values, and significant differences in fragrance are found among different Lilium genotypes. In order to explore the mechanism underlying the different fragrances, the floral scents of Lilium 'Sibeia', with a strong fragrance, and Lilium 'Novano', with a very faint fragrance, were collected in vivo using a dynamic headspace technique. These scents were identified using automated thermal desorption-gas chromatography/mass spectrometry (ATD-GC/MS) at different flowering stages. We used RNA-Seq technique to determine the petal transcriptome at the full-bloom stage and analyzed differentially expressed genes (DEGs) to investigate the molecular mechanism of floral scent biosynthesis. The results showed that a significantly higher amount of Lilium 'Siberia' floral scent was released compared with Lilium 'Novano'. Moreover, monoterpenes played a dominant role in the floral scent of Lilium 'Siberia'; therefore, it is believed that the different emissions of monoterpenes mainly contributed to the difference in the floral scent between the two Lilium genotypes. Transcriptome sequencing analysis indicated that ~29.24 Gb of raw data were generated and assembled into 124,233 unigenes, of which 35,749 unigenes were annotated. Through a comparison of gene expression between these two Lilium genotypes, 6,496 DEGs were identified. The genes in the terpenoid backbone biosynthesis pathway showed significantly different expression levels. The gene expressions of 1-deoxy-D-xylulose 5-phosphate synthase (DXS), 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), 4-hydroxy-3-methylbut-2-enyl diphosphate synthase (HDS), 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR), isopentenyl diphosphate isomerase (IDI), and geranyl diphosphate synthase (GPS/GGPS), were upregulated in Lilium 'Siberia' compared to Lilium 'Novano', and two monoterpene synthase genes, ocimene synthase gene (OCS) and myrcene synthase gene (MYS), were also expressed at higher levels in the tepals of Lilium 'Siberia', which was consistent with the monoterpene release amounts. We demonstrated that the high activation levels of the pathways contributed to monoterpene biosynthesis in Lilium 'Siberia' resulting in high accumulations and emissions of monoterpenes, which led to the difference in fragrance between these two Lilium genotypes.

Seasonal variability of the essential oil of Hesperozygis ringens (Benth.) Epling

This study was developed to evaluate the effect of seasonality on the yield and chemical composition of the essential oil (EO) of Hesperozygis ringens (Benth.) Epling, a native species from the Brazilian Pampa. Leaves were collected from four specimens of a single population in each of the four seasons for a year and were extracted in triplicate by hydro-distillation for 2 hours. The yield of EO (% w/w) was calculated on fresh weight basis (FWB), and the 16 oil samples were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were used as statistical tools to evaluate differences in chemical composition. The highest yields were obtained in autumn, spring and summer (2.32-4.38%), while the lowest yields were detected in winter, ranging from 1.15 to 1.91%. Oxygenated monoterpenoids were the predominant class of chemical constituents in the EO obtained in all seasons, showing the highest contents in autumn and summer, and pulegone was identified as a major compound, whose contents varied between 54.13 and 81.17%. The EO samples were divided into three chemical groups by HCA and PCA and were assigned to the same group, except for the three samples gathered in winter. The results showed a seasonal influence on the yield and chemical composition of the EO.

Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition

Sage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample.

Ca²⁺ signal contributing to the synthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia'

The floral scent is an important part of plant volatile compounds, and is influenced by environmental factors. The emission of monoterpenes of Lilium 'siberia' is regulated by light intensity, but the mechanism is large unknown. In this study, the expression of Li-mTPS, a monoterpene synthase gene in the tepals of Lilium 'siberia', and net Ca(2+) flux were investigated after exposure to different levels of light intensity (0, 100, 300, 600, 1000, and 1500 μmol m(-2) s(-1)). Moreover the effect of LaCl3 and ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) on the Li-mTPS expression, monoterpene emission, and net Ca(2+) flux were examined at 600 μmol m(-2) s(-1). The results showed that along with the enhancement of light intensity, the expression level of Li-mTPS increased gradually, and the net Ca(2+) influx was also enhanced showing a similar pattern. It was found that LaCl3 and EGTA effectively inhibited the increase in expression of Li-mTPS and the net Ca(2+) influx induced by light treatment. Moreover, the release amounts of monoterpenes decreased significantly after treatment with LaCl3 and EGTA. So it can be concluded that Ca(2+) signal contributed to the biosynthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia' tepals. The increased light intensity firstly triggered the Ca(2+) influx to cytoplasm, and then the gene expression of monoterpene synthases downstream was activated to regulate the biosynthesis and emission of monoterpenes. But in the signaling pathway other mechanisms were thought to be involved in the emission of monoterpenes regulated by light intensity, which need to be investigated in future research.

Protective properties of Salvia lavandulifolia Vahl. essential oil against oxidative stress-induced neuronal injury

Salvia lavandulifolia Vahl., known as "Spanish sage", has potential value in dementia for its sedative, antioxidant, anti-inflammatory and anticholinesterase properties. This work aimed to evaluate the in vitro neuroprotective activity of S. lavandulifolia essential oils, obtained from plants at different phenological stages (vegetative and flowering phases) and plants grown at different densities, against H2O2-induced oxidative stress in PC12 cells. The effect on cell viability and morphology, lipid peroxidation, GSH/GSSG ratio, intracellular ROS levels, antioxidant enzymes (CAT, SOD, GR, GPx, HO-1) and apoptotic enzymes was investigated. Comparing with H2O2-treated PC12 cells, pretreatments with essential oil samples attenuated morphological changes and loss of cell viability, decreased MDA levels and intracellular ROS production and increased GSH/GSSG ratio. Moreover, Spanish sage increased antioxidant status as evidenced in an increase of antioxidant enzyme activity and protein expression and inhibited caspase-3 activity. Furthermore, our results suggest that S. lavandulifolia essential oils are able to activate Nrf2 transcription factor. Collectively, the sample of essential oil obtained with the highest densities of planting and at flowering phase exerted the major neuroprotective activity. Our findings demonstrate that S. lavandulifolia essential oils may have therapeutic value for the prevention and treatment of neurodegenerative diseases associated with oxidative stress-induced neuronal injury.

Deciphering the language of plant communication: volatile chemotypes of sagebrush

Volatile communication between sagebrush (Artemisia tridentata) individuals has been found previously to reduce herbivory and to be more effective between individuals that are genetically identical or related relative to between strangers. The chemical nature of the cues involved in volatile communication remains unknown for this and other systems. We collected headspace volatiles from sagebrush plants in the field and analyzed these using GC-MS. Volatile profiles were highly variable among individuals, but most individuals could be characterized as belonging to one of two chemotypes, dominated by either thujone or camphor. Analyses of parents and offspring revealed that chemotypes were highly heritable. The ecological significance of chemotypes and the genetic mechanisms that control them remain poorly understood. However, we found that individuals of the same chemotype communicated more effectively and experienced less herbivory than individuals of differing chemotypes. Plants may use chemotypes to distinguish relatives from strangers.

Seasonal Influence on the Essential Oil of Eucalyptus microcorys

The chemical composition of the essential oil, phenolic contents, and foliar nutrients of Eucalyptus microcorys leaves, cultivated in Brazil, was analysed on a monthly basis for one year. Canonical redundancy analysis correlated results with climate conditions (rainfall, humidity, and mean temperature), allowing three groups to be distinguished as regards temperature, flavonoids, and the content of some metals. Strong correlations between Mn, Cu, Zn, Ca, P, and K with some monoterpenes and phenolic compounds were observed. Oxygenated monoterpenes were predominant in all sampling months. Oil chemovariation may be influenced by climatic factors as well as by foliar nutrient variation.

Differences in shoot and root terpenoid profiles and plant responses to fertilisation in Tanacetum vulgare

Intraspecific chemical diversity is a common phenomenon especially found in shoots of essential oil-accumulating plant species. Abiotic factors can influence the concentration of essential oils, but the effects are inconsistent and little is known in how far these may vary within an individual and within species between chemotypes. Tanacetum vulgare L. occurs in various chemotypes that differ in the composition of mono- and sesquiterpenoids in their shoot tissues. We investigated how far shoot chemotype grouping is mirrored in root terpenoid profiles. Furthermore, we studied whether different fertilisation amounts influence the plant growth and morphological traits as well as the constitutive terpenoid concentration of leaves and roots of three chemotypes, trans-carvyl acetate, β-thujone, and camphor, to different degrees. Shoot terpenoids were dominated by monoterpenoids, while the roots contained mainly sesquiterpenoids. The clear grouping in three chemotypes based on leaf chemistry was weakly mirrored in the root terpenoid composition. Furthermore, the leaf C/N ratio and the stem height differed between chemotypes. All plants responded to increased nutrient availability with increased total biomass and specific leaf area but decreased C/N and root/shoot ratios. Leaf terpenoid concentrations decreased with increasing fertiliser supply, independent of chemotype. In contrast to the leaves, the terpenoid concentrations of the roots were unaffected by fertilisation. Our results demonstrate that aboveground and belowground organs within a species can be under different selection pressures.

Essential oil of common sage (Salvia officinalis L.) from Jordan: assessment of safety in mammalian cells and its antifungal and anti-inflammatory potential

Salvia officinalis L. (Lamiaceae) is a Mediterranean species, naturalized in many countries. In Jordan, it is used in traditional medicine as antiseptic, antiscabies, antisyphilitic, and anti-inflammatory, being frequently used against skin diseases. This study aimed the assessment of the antifungal and anti-inflammatory potential of its essential oils, and their cytotoxicity on macrophages and keratinocytes. The oils were investigated by gas chromatography and gas chromatography-mass spectrometry and the antifungal activity was evaluated against yeasts, dermatophyte and Aspergillus strains. Assessment of cell viability was made by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and the in vitro anti-inflammatory potential was evaluated by measuring nitric oxide production using lipopolysaccharide-stimulated mouse macrophages. The main compounds of S. officinalis oils were 1,8-cineole (39.5–50.3%) and camphor (8.8–25.0%). The oils revealed antifungal activity against dermatophyte strains and significantly inhibited NO production stimulated by LPS in macrophages, without affecting cell viability, in concentrations up to 0.64 μL/mL. This is the first report addressing the in vitro anti-inflammatory potential of S. officinalis oil. These findings demonstrated that bioactive concentrations of S. officinalis oils do not affect mammalian macrophages and keratinocytes viability making them suitable to be incorporated in skin care formulations for cosmetic and pharmaceutical purposes.

Evaluation of PCR-ELISA as a tool for monitoring transmission of Wuchereria bancrofti in District of Gampaha, Sri Lanka

OBJECTIVE

To compare Wuchereria bancrofti (W. bancrofti) infection rates of Culex quinquefasciatus, using dissection and PCR-ELISA in two consecutive time periods (from 2007 to 2008 and from 2008 to 2009).

METHODS

Mosquitoes were collected in 30 sentinel and 15 non-sentinel sites in 15 Medical Officer of Health areas of Gampaha District known for the presence of W. bancrofti transmission in two consecutive time period of 2007 to 2008 and 2008 to 2009. Captured mosquitoes were dissected to determine the W. bancrofti larvae (L1, L2, L3). PCR was carried out using DNA extracted from mosquito pools (15 body parts/pool) utilizing the primers specific for Wb-SspI repeat. PCR products were analyzed by hybridization ELISA using fluorescein-labeled wild type specific probes. The prevalence of infected/infective mosquitoes in PCR pools (3 pools/site) was estimated using the PoolScreen™ algorithm and a novel probability-based method.

RESULTS

Of 45 batches of mosquitoes dissected, W. bancrofti infected mosquitoes were found in 19 and 13 batches, with an infection rate of 13.29% and 3.10% with mean larval density of 8.7 and 1.0 larvae per mosquito for two study periods in the Gampaha District. Total of 405 pools of head, thorax and abdomen were processed by PCR-ELISA for each year. Of these, 51 and 31 pools were positive for W. bancrofti in the two study periods respectively. The association of dissection based prevalence rates with PCR based rates as determined by the Pearson correlation coefficient were 0.176 and 0.890 respectively for the two periods.

CONCLUSIONS

Data indicate that PCR-ELISA is more sensitive than the traditional dissection techniques for monitoring transmission intensity.