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Soheil S. Mahmoud - One of the best experts on this subject based on the ideXlab platform.
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rna seq in the discovery of a sparsely expressed scent determining monoterpene synthase in lavender Lavandula
Planta, 2019Co-Authors: Ayelign M. Adal, Lukman S Sarker, Radesh P N Malli, Ping Liang, Soheil S. MahmoudAbstract:Using RNA-Seq, we cloned and characterized a unique monoterpene synthase responsible for the formation of a scent-determining S-linalool constituent of lavender oils from Lavandula × intermedia. Several species of Lavandula produce essential oils (EOs) consisting mainly of monoterpenes including linalool, one of the most abundant and scent-determining oil constituents. Although R-linalool dominates the EOs of lavenders, varying amounts (depending on the species) of the S-linalool enantiomer can also be found in these plants. Despite its relatively low abundance, S-linalool contributes a sweet, pleasant scent and is an important constituent of lavender EOs. While several terpene synthase genes including R-linalool synthase have been cloned from lavenders many important terpene synthases including S-linalool synthase have not been described from these plants. In this study, we employed RNA-Seq and other complementary sequencing data to clone and functionally characterize the sparsely expressed S-linalool synthase cDNA (LiS-LINS) from Lavandula × intermedia. Recombinant LiS-LINS catalyzed the conversion of the universal monoterpene precursor geranyl diphosphate to S-linalool as the sole product. Intriguingly, LiS-LINS exhibited very low (~ 30%) sequence similarity to other Lavandula terpene synthases, including R-linalool synthase. However, the predicted 3D structure of this protein, including the composition and arrangement of amino acids at the active site, is highly homologous to known terpene synthase proteins. LiS-LINS transcripts were detected in flowers, but were much less abundant than those corresponding to LiR-LINS, paralleling enantiomeric composition of linalool in L. × intermedia oils. These data indicate that production of S-linalool is at least partially controlled at the level of transcription from LiS-LINS. The cloned LiS-LINS cDNA may be used to enhance oil composition in lavenders and other plants through metabolic engineering.
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isolation and functional characterization of a methyl jasmonate responsive 3 carene synthase from Lavandula x intermedia
Plant Molecular Biology, 2017Co-Authors: Ayelign M. Adal, Lukman S Sarker, Ashley D Lemke, Soheil S. MahmoudAbstract:Key message A methyl jasmonate responsive 3-carene synthase (Li3CARS) gene was isolated from Lavandula x intermedia and functionally characterized in vitro.
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Identification, validation and cross-species transferability of novel Lavandula EST-SSRs.
Planta, 2014Co-Authors: Ayelign M. Adal, Zerihun A. Demissie, Soheil S. MahmoudAbstract:We identified and characterized EST-SSRs with strong discrimination power against Lavandula angustifolia and Lavandula x intermedia . The markers also showed considerable cross-species transferability rate into six related Lavandula species. Lavenders (Lavandula) are important economical crops grown around the globe for essential oil production. In an attempt to develop genetic markers for these plants, we analyzed over 13,000 unigenes developed from L. angustifolia and L. x intermedia EST databases, and identified 3,459 simple sequence repeats (SSR), which were dominated by trinucleotides (41.2 %) and dinucleotides (31.45 %). Approximately, 19 % of the unigenes contained at least one SSR marker, over 60 % of which were localized in the UTRs. Only 252 EST-SSRs were 18 bp or longer from which 31 loci were validated, and 24 amplified discrete fragments with 85 % polymorphism in L. x intermedia and L. angustifolia. The average number of alleles in L. x intermedia and L. angustifolia were 3.42 and 3.71 per marker with average PIC values of 0.47 and 0.52, respectively. These values suggest a moderate to strong level of informativeness for the markers, with some loci producing unique fingerprints. The cross-species transferability rate of the markers ranges 50–100 % across eight species. The utility of these markers was assessed in eight Lavandula species and 15 L. angustifolia and L. x intermedia cultivars, and the dendrogram deduced from their similarity indexes successfully delineated the species into their respective sections and the cultivars into their respective species. These markers have potential for application in fingerprinting, diversity studies and marker-assisted breeding of Lavandula.
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molecular cloning and functional characterization of borneol dehydrogenase from the glandular trichomes of Lavandula x intermedia
Archives of Biochemistry and Biophysics, 2012Co-Authors: Lukman S Sarker, Zerihun A. Demissie, Mariana Galata, Soheil S. MahmoudAbstract:Several varieties of Lavandula x intermedia (lavandins) are cultivated for their essential oils (EOs) for use in cosmetic, hygiene and personal care products. These EOs are mainly constituted of monoterpenes including camphor, which contributes an off odor reducing the olfactory appeal of the oil. We have recently constructed a cDNA library from the glandular trichomes (the sites of EO synthesis) of L. x intermedia plants. Here, we describe the cloning of a borneol dehydrogenase cDNA (LiBDH) from this library. The 780 bp open reading frame of the cDNA encoded a 259 amino acid short chain alcohol dehydrogenase with a predicted molecular mass of ca. 27.5 kDa. The recombinant LiBDH was expressed in Escherichia coli, purified by Ni-NTA agarose affinity chromatography, and functionally characterized in vitro. The bacterially produced enzyme specifically converted borneol to camphor as the only product with K(m) and k(cat) values of 53 μM and 4.0 × 10(-4) s(-1), respectively. The LiBDH transcripts were specifically expressed in glandular trichomes of mature flowers indicating that like other Lavandula monoterpene synthases the expression of this gene is regulated in a tissue-specific manner. The cloning of LiBDH has far reaching implications in improving the quality of Lavandula EOs through metabolic engineering.
Maria Graça Miguel - One of the best experts on this subject based on the ideXlab platform.
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Essential oils of spontaneous species of the genus Lavandula from Portugal: a brief review
Zeitschrift für Naturforschung C, 2020Co-Authors: Jessica Vairinhos, Maria Graça MiguelAbstract:Spontaneous lavender growing in uncultivated fields in Portugal have been used in traditional medicine for internal and external uses. The essential oils (EOs) of Lavandula stoechas subsp. luisieri are characterized by the presence of trans-α-necrodyl acetate and trans-necrodol. These EOs are able to prevent the generation and deposition of neurotoxic β-amyloid peptide in Alzheimer's disease. The EOs also present antibacterial, anti-fungal, anti-Leishmania, antioxidant, anti-inflammatory and antifeedant effects. In the case of hydrodistillation, the predominant compound of Lavandula viridis EO was 1,8-cineole, nevertheless in the case of supercritical fluid extraction, the main constituent was camphor. In in vitro shoots EOs, 1,8-cineole and α-pinene were the most important compounds. The EOs presented anti-fungal activity particularly against Cryptococcus neoformans and dermatophytes. The antioxidant and anti-protozoal activities of L. viridis EOs were lower than L. stoechas subsp. luisieri EOs, with hydrodistillation being the best method for obtaining samples with higher antioxidant and anti-acetylcholinesterase activities. The presence of fenchone, 1,8-cineole and camphor was a common trace of the Lavandula pedunculata subsp. pedunculata EOs and in in vitro axillary shoots EOs. Lavandula pedunculata subsp. lusitanica EOs were predominantly constituted of fenchone and camphor. The antioxidant activity of L. pedunculata subsp. lusitanica EOs was poorer than other Lavandula EOs from Portugal.
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comparative study of gc ms characterization antioxidant activity and hyaluronidase inhibition of different species of Lavandula and thymus essential oils
Flavour and Fragrance Journal, 2016Co-Authors: Alejandro Carrasco, Virginia Tomas, Jose Tudela, Maria Graça MiguelAbstract:The chemical compositions of essential oils of Lavandula angustifolia, Lavandula latifolia, Lavandula hybrida cultivar Grosso and cultivar Super, Thymus zygis with high proportions of thymol and linalool and Thymus hyemalis, from Murcia country (Spain), were studied in relative (%), absolute (mM) and chiral concentrations by GC/MS. Hyaluronidase inhibition and antioxidant activities of the essential oils were evaluated using ABTS•+, DPPH•, ORAC, chelating power, hydroxyl radical, nitric oxide, TBARS and reducing power assays. Linalool and linalyl acetate were the most abundant components in the Lavandula genus whereas thymol, linalool and 1,8-cineole were the most abundant molecules in the respective Thymus species. Chiral determination of the main components showed (+)-enantiomers like terpinen-4-ol, β-pinene, borneol and α-terpineol and (−)-enantiomers like linalool, linalyl acetate and camphene in Lavandula sp. In the case of Thymus sp. (+)-enantiomers like α-pinene, limonene, terpinen-4-ol and α-terpineol and (−)-enantiomers like borneol were found. Essential oils containing thymol were found especially powerful in all assays but chelating power, ORAC and hydroxyl radical scavenging assays. The capacity for inhibiting hyaluronidase showed that T. zygis with a high proportion of thymol was the most effective inhibitor. Essential oils containing thymol and linalool/linalyl acetate have a potential use as antioxidant agents. Thymol shows strong inhibition of hyaluronidase. Copyright © 2015 John Wiley & Sons, Ltd.
Mitra Taghizadeh - One of the best experts on this subject based on the ideXlab platform.
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comparison of Lavandula angustifolia mill tincture and imipramine in the treatment of mild to moderate depression a double blind randomized trial
Progress in Neuro-psychopharmacology & Biological Psychiatry, 2003Co-Authors: Shahin Akhondzadeh, Ladan Kashani, Akbar Fotouhi, Soghra Jarvandi, Mansour Mobaseri, Mahdiyeh Moin, M Khani, A H Jamshidi, Kambiz Baghalian, Mitra TaghizadehAbstract:Depression is a major health problem and is not only underrecognized and undertreated but is associated with significant morbidity and mortality. Lavandula angustifolia Mill. (Lamiacae) is used to treat depression. Many medicinal plant textbooks refer to this indication, whereas there is no evidence-based document. Our objective was to compare the efficacy of tincture of L. angustifolia with imipramine in the treatment of mild to moderate depression and to evaluate the possible adjuvant effect of this tincture in a 4 week double-blind, randomized trial. Forty-five adult outpatients who met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for major depression based on the structured clinical interview for DSM IV participated in the trial. Patients have a baseline Hamilton Rating Scale for Depression score of at least 18. In this double-blind, single-center trial, patients were randomly assigned to receive Lavandula tincture (1:5 in 50% alcohol ) 60 drops/day plus placebo tablet (Group A), tablet imipramine 100 mg/day plus placebo drop (Group B) and tablet imipramine 100 mg/day plus Lavandula tincture 60 drops/day (Group C) for a 4-week study. In this small preliminary double-blind and randomized trial, Lavandula tincture at this concentration was found to be less effective than imipramine in the treatment of mild to moderate depression (F=13.16, df=1, P=.001). In the imipramine group, anticholinergic effects such as dry mouth and urinary retention were observed more often that was predictable, whereas headache was observed more in the Lavandula tincture group. A combination of imipramine and Lavandula tincture was more effective than imipramine alone (F=20.83, df=1, P<.0001). As this study indicates, one of the advantages of this combination is a better and earlier improvement. The main overall finding from this study is that Lavandula tincture may be of therapeutic benefit in the management of mild to moderate depression as adjuvant therapy. A large-scale trial is justified.
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Comparison of Lavandula angustifolia Mill. tincture and imipramine in the treatment of mild to moderate depression: a double-blind, randomized trial
Progress in Neuro-psychopharmacology & Biological Psychiatry, 2003Co-Authors: Shahin Akhondzadeh, Ladan Kashani, Akbar Fotouhi, Soghra Jarvandi, Mansour Mobaseri, Mahdiyeh Moin, M Khani, A H Jamshidi, Kambiz Baghalian, Mitra TaghizadehAbstract:Depression is a major health problem and is not only underrecognized and undertreated but is associated with significant morbidity and mortality. Lavandula angustifolia Mill. (Lamiacae) is used to treat depression. Many medicinal plant textbooks refer to this indication, whereas there is no evidence-based document. Our objective was to compare the efficacy of tincture of L. angustifolia with imipramine in the treatment of mild to moderate depression and to evaluate the possible adjuvant effect of this tincture in a 4 week double-blind, randomized trial. Forty-five adult outpatients who met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for major depression based on the structured clinical interview for DSM IV participated in the trial. Patients have a baseline Hamilton Rating Scale for Depression score of at least 18. In this double-blind, single-center trial, patients were randomly assigned to receive Lavandula tincture (1:5 in 50% alcohol ) 60 drops/day plus placebo tablet (Group A), tablet imipramine 100 mg/day plus placebo drop (Group B) and tablet imipramine 100 mg/day plus Lavandula tincture 60 drops/day (Group C) for a 4-week study. In this small preliminary double-blind and randomized trial, Lavandula tincture at this concentration was found to be less effective than imipramine in the treatment of mild to moderate depression (F=13.16, df=1, P=.001). In the imipramine group, anticholinergic effects such as dry mouth and urinary retention were observed more often that was predictable, whereas headache was observed more in the Lavandula tincture group. A combination of imipramine and Lavandula tincture was more effective than imipramine alone (F=20.83, df=1, P
Lukman S Sarker - One of the best experts on this subject based on the ideXlab platform.
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rna seq in the discovery of a sparsely expressed scent determining monoterpene synthase in lavender Lavandula
Planta, 2019Co-Authors: Ayelign M. Adal, Lukman S Sarker, Radesh P N Malli, Ping Liang, Soheil S. MahmoudAbstract:Using RNA-Seq, we cloned and characterized a unique monoterpene synthase responsible for the formation of a scent-determining S-linalool constituent of lavender oils from Lavandula × intermedia. Several species of Lavandula produce essential oils (EOs) consisting mainly of monoterpenes including linalool, one of the most abundant and scent-determining oil constituents. Although R-linalool dominates the EOs of lavenders, varying amounts (depending on the species) of the S-linalool enantiomer can also be found in these plants. Despite its relatively low abundance, S-linalool contributes a sweet, pleasant scent and is an important constituent of lavender EOs. While several terpene synthase genes including R-linalool synthase have been cloned from lavenders many important terpene synthases including S-linalool synthase have not been described from these plants. In this study, we employed RNA-Seq and other complementary sequencing data to clone and functionally characterize the sparsely expressed S-linalool synthase cDNA (LiS-LINS) from Lavandula × intermedia. Recombinant LiS-LINS catalyzed the conversion of the universal monoterpene precursor geranyl diphosphate to S-linalool as the sole product. Intriguingly, LiS-LINS exhibited very low (~ 30%) sequence similarity to other Lavandula terpene synthases, including R-linalool synthase. However, the predicted 3D structure of this protein, including the composition and arrangement of amino acids at the active site, is highly homologous to known terpene synthase proteins. LiS-LINS transcripts were detected in flowers, but were much less abundant than those corresponding to LiR-LINS, paralleling enantiomeric composition of linalool in L. × intermedia oils. These data indicate that production of S-linalool is at least partially controlled at the level of transcription from LiS-LINS. The cloned LiS-LINS cDNA may be used to enhance oil composition in lavenders and other plants through metabolic engineering.
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isolation and functional characterization of a methyl jasmonate responsive 3 carene synthase from Lavandula x intermedia
Plant Molecular Biology, 2017Co-Authors: Ayelign M. Adal, Lukman S Sarker, Ashley D Lemke, Soheil S. MahmoudAbstract:Key message A methyl jasmonate responsive 3-carene synthase (Li3CARS) gene was isolated from Lavandula x intermedia and functionally characterized in vitro.
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molecular cloning and functional characterization of borneol dehydrogenase from the glandular trichomes of Lavandula x intermedia
Archives of Biochemistry and Biophysics, 2012Co-Authors: Lukman S Sarker, Zerihun A. Demissie, Mariana Galata, Soheil S. MahmoudAbstract:Several varieties of Lavandula x intermedia (lavandins) are cultivated for their essential oils (EOs) for use in cosmetic, hygiene and personal care products. These EOs are mainly constituted of monoterpenes including camphor, which contributes an off odor reducing the olfactory appeal of the oil. We have recently constructed a cDNA library from the glandular trichomes (the sites of EO synthesis) of L. x intermedia plants. Here, we describe the cloning of a borneol dehydrogenase cDNA (LiBDH) from this library. The 780 bp open reading frame of the cDNA encoded a 259 amino acid short chain alcohol dehydrogenase with a predicted molecular mass of ca. 27.5 kDa. The recombinant LiBDH was expressed in Escherichia coli, purified by Ni-NTA agarose affinity chromatography, and functionally characterized in vitro. The bacterially produced enzyme specifically converted borneol to camphor as the only product with K(m) and k(cat) values of 53 μM and 4.0 × 10(-4) s(-1), respectively. The LiBDH transcripts were specifically expressed in glandular trichomes of mature flowers indicating that like other Lavandula monoterpene synthases the expression of this gene is regulated in a tissue-specific manner. The cloning of LiBDH has far reaching implications in improving the quality of Lavandula EOs through metabolic engineering.
Begona Peco - One of the best experts on this subject based on the ideXlab platform.
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lack of recruitment in Lavandula stoechas subsp pedunculata a case of safe site limitation
Acta Oecologica-international Journal of Ecology, 2007Co-Authors: A Sanchez, Begona PecoAbstract:Lavandula stoechas subsp. pedunculata regeneration depends exclusively on the establishment of new individuals. Seed availability and seedling emergence and survival are therefore critical life stages and processes for species regeneration. In this study, seedling emergence and survival was monitored for two years in the scrub, both in clearings and adjacent to adult plants, and the surrounding perennial grassland, at 1, 3 and 5 m from the scrub. Soil seed bank spatial distribution was also studied for one year in the same two habitats, using the same sampling design. Soil seed availability in the scrub is high regardless of the distance from the adult individuals. On the contrary, the adjacent grassland shows a drastic fall in seed density, and almost no seedlings were observed there. In the scrub, seedling density was negatively related to distance from the three nearest adult plants in the clearings, and positively related to adult plant size beneath the adult Lavandula plants. There was also a negative relationship between seedling density and the percentage of bare soil. Only one seedling survived the first drought period, with no detection of effects of either position with respect to adult individuals or seedling density. We hypothesized that the study populations suffer a lack of appropriate safe sites within the scrubland while in the adjacent perennial grassland, observed low seed availability was added to safe-site limitation. That results in a lack of successful seedling establishments and a poor expansion potential of Lavandula scrublands, whose edges remain static in the short and medium term. As found in other Mediterranean scrubland, recruitment may only occur in years with particularly favourable weather, under disturbance regimes that increase seedling survival probability or when external dispersal agents increased seed availability in adequate places for Lavandula establishment.
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effects of harvester ants on seed availability and dispersal of Lavandula stoechas subsp pedunculata in a mediterranean grassland scrubland mosaic
Plant Ecology, 2006Co-Authors: A Sanchez, Francisco M Azcarate, Begona PecoAbstract:The role of harvester ants in Mediterranean grassland and scrubland has mostly focused on seed consumption. However, recent studies have reported their role as accidental dispersal agents of some of the collected seeds via refuse piles. The objective of this study is to examine the effect of the ant Messor barbarus on seed availability and dispersal of one of its major diet components, Lavandula stoechas subsp. pedunculata, in scrubland, grassland and the ecotones between them. After confirming and quantifying the Lavandula contribution to M. barbarus diet, we described the spatial and temporal patterns of pre- and post-dispersal seed predation, seed content and seedling occurrence in the refuse piles. Our results show that: (1) Lavandula propagules constitute a high proportion of the prey items collected by M. barbarus, with particularly intense collection activity in mid-summer, spring and autumn, in decreasing order. (2) Pre-dispersal predation rate was significantly higher in the ecotone than in the scrubland (76% and 13.5% of total seed production lost respectively). (3) Season and propagule type (seed vs. fruit) were the most significant variables explaining the post-dispersal predation probability, which approached 100% of seeds after 48 h in mid-summer. (4) Viable Lavandula seeds were found in refuse piles at densities of 0.06–0.2 per g of refuse pile material, or 58.8–207.2 per refuse pile. On the one hand, these results indicate that the ecotones are most affected by M. barbarus pre-dispersal consumption, which may locally limit Lavandula colonisation. On the other hand, the small proportion of consumed seeds that is dispersed to refuse piles may be relevant at the population level, as this dispersal implies arrival at potentially favourable sites for establishment.
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interference between perennial grassland and Lavandula stoechas subsp pedunculata seedlings a case of spatial segregation cause by competition
Acta Oecologica-international Journal of Ecology, 2004Co-Authors: A Sanchez, Begona PecoAbstract:This paper analyses the relationship between Lavandula stoechas subsp. pedunculata, a common Mediterranean scrub species in central Iberia, and perennial grasslands. While Lavandula gives rise to almost monospecific formations in intermediate and upper hill zones, perennial grasses occupy the low areas. The proposed explanatory hypothesis for this spatial distribution is that the scrub is unable to establish itself in grasslands with heavy spatial occupation. We designed two experiments to test this hypothesis, one which analysed the effect of perennial grass cover on Lavandula establishment, and another which focused on its influence on previously implanted seedling survival and growth, distinguishing the effect of shoot and root interference. The results show negative interference during establishment and later in the use of light and nutrients. This results in a very low overall survival probability, with only 1.4% of seedlings surviving the first growth period. This low success rate explains the existence of a clear spatial segregation between scrub patches and perennial-dominated grasslands.
