Metabolic engineering of terpene metabolism in lavender.

Background: Several members of the Lamiaceae family of plants produce large amounts of essential oil [EO] that find extensive applications in the food, cosmetics, personal hygiene, and alternative medicine industries. There is interest in enhancing EO metabolism in these plants.

Main Body: Lavender produces a valuable EO that is highly enriched in monoterpenes, the C class of the isoprenoids or terpenoids.

Cloning, functional characterization and evaluating potential in metabolic engineering for lavender ( +)-bornyl diphosphate synthase.

We isolated and functionally characterized a new ( +)-bornyl diphosphate synthase (( +)-LiBPPS) from Lavandula x intermedia. The in planta functions of ( +)-LiBPPS were evaluated in sense and antisense transgenic plants. The monoterpene ( +)-borneol contributes scent and medicinal properties to some plants.

Expression of lavender AGAMOUS-like and SEPALLATA3-like genes promote early flowering and alter leaf morphology in Arabidopsis thaliana.

The expression of full-length cDNAs encoding lavender AGAMOUS-like (LaAG-like) and SEPALLATA3-like (LaSEP3-like) transcription factors induces early flowering and impacts the leaf morphology at a strong expression level in Arabidopsis. Lavandula angustifolia is widely cultivated as an ornamental plant due to its attractive flower structure, and as a source of valuable essential oils for use in cosmetics, alternative medicines, and culinary products. We recently employed RNA-Seq and transcript profiling to describe a number of transcription factors (TFs) that potentially control flower development in this plant.

Isoprenoid Metabolism and Engineering in Glandular Trichomes of .

The isoprenoids play important ecological and physiological roles in plants. They also have a tremendous impact on human lives as food additives, medicines, and industrial raw materials, among others. Though some isoprenoids are highly abundant in nature, plants produce many at extremely low levels.

Comparative RNA-Seq analysis reveals genes associated with masculinization in female Cannabis sativa.

Using RNA profiling, we identified several silver thiosulfate-induced genes that potentially control the masculinization of female Cannabis sativa plants. Genetically female Cannabis sativa plants normally bear female flowers, but can develop male flowers in response to environmental and developmental cues. In an attempt to elucidate the molecular elements responsible for sex expression in C.

Short-chain isoprenyl diphosphate synthases of lavender (Lavandula).

We reported the functional characterization of cDNAs encoding short-chain isoprenyl diphosphate synthases that control the partitioning of precursors for lavender terpenoids. Lavender essential oil is composed of regular and irregular monoterpenes, which are derived from linear precursors geranyl diphosphate (GPP) and lavandulyl diphosphate (LPP), respectively. Although this plant strongly expresses genes responsible for the biosynthesis of both monoterpene classes, it is unclear why regular monoterpenes dominate the oil.

Cloning and functional characterization of a floral repressor gene from Lavandula angustifolia.

Using RNA-Seq, we identified genes involved in floral development in lavenders and functionally characterized the floral repressor LaSVP. The molecular aspects of flower initiation and development have not been adequately investigated in lavender (Lavandula). In order to identify genes that control these processes, we employed RNA-Seq to obtain sequence information for transcripts originating from the vegetative shoot apical meristem (SAM) and developing inflorescence tissues of Lavandula angustifolia and Lavandula × intermedia plants, and assemble a comprehensive transcriptome of 105,294 contigs.

Diverse transcription factors control monoterpene synthase expression in lavender (Lavandula).

We cloned eight transcription factors that activate lavender monoterpene synthase promoters. In this study, we employed the Yeast One-Hybrid (Y1H) assay system to identify transcription factors that control promoters for two Lavandula × intermedia monoterpene synthase genes, linalool synthase (LiLINS) and 1,8-cineole synthase (LiCINS). The bait sequences used in the assay were either a 768-bp LiLINS, or a 1087-bp LiCINS promoter.

A lavender ABC transporter confers resistance to monoterpene toxicity in yeast.

Functional expression of a multidrug resistance-type ABC transporter from Lavandulaangustifolia improved yeast resistance to geraniol, a monoterpene constituent of lavender essential oil. Plant ATP-binding cassette (ABC) transporters are a large family of membrane proteins involved in active and selective transport of structurally diverse compounds. In this study, we functionally evaluated LaABCB1, a multidrug resistance (MDR)-type ABC transporter strongly expressed in the secretory cells of lavender glandular trichomes, where monoterpene essential oil constituents are synthesized and secreted.

De novo sequencing of the Lavandula angustifolia genome reveals highly duplicated and optimized features for essential oil production.

The first draft genome for a member of the genus Lavandula is described. This 870 Mbp genome assembly is composed of over 688 Mbp of non-gap sequences comprising 62,141 protein-coding genes. Lavenders (Lavandula: Lamiaceae) are economically important plants widely grown around the world for their essential oils (EOs), which contribute to the cosmetic, personal hygiene, and pharmaceutical industries.

RNA-Seq in the discovery of a sparsely expressed scent-determining monoterpene synthase in lavender (Lavandula).

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.

Isolation and functional characterization of a methyl jasmonate-responsive 3-carene synthase from Lavandula x intermedia.

A methyl jasmonate responsive 3-carene synthase (Li3CARS) gene was isolated from Lavandula x intermedia and functionally characterized in vitro. Lavenders produce essential oils consisting mainly of monoterpenes, including the potent antimicrobial and insecticidal monoterpene 3-carene. In this study we isolated and functionally characterized a leaf-specific, methyl jasmonate (MeJA)-responsive monoterpene synthase (Li3CARS) from Lavandula x intermedia.

Antifungal Screening of Lavender Essential oils and Essential Oil Constituents on three Post-harvest Fungal Pathogens.

A growing body of literature indicates that many synthetic pesticides have adverse effects on human, animal, and environmental health. As a result, plant-derived natural products are quickly gaining momentum as safer and less ecologically damaging alternatives due to their low toxicity, high biodegradability, and good specificity. Essential oils of Lavandula angustifolia, Lavandula x intermedia cv Grosso, and Lavandida x intermedia cv Provence as well as various mono- and sesquiterpene essential oil constituents were tested in order to assess their antifungal potential on three important agricultural pathogens: Botrytis cinerea, Mucor piriformis, and Penicillium expansum.

Cloning and functional characterization of two monoterpene acetyltransferases from glandular trichomes of L. x intermedia.

Two alcohol acetyltransferases, LiAAT-3 and LiAAT-4, from L. x intermedia were cloned, expressed in bacteria, and functionally characterized. Two monoterpene acetyltransferase cDNA clones (LiAAT-3 and LiAAT-4) were isolated from L.

Identification, validation and cross-species transferability of novel Lavandula EST-SSRs.

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.

Transcriptome profiling, and cloning and characterization of the main monoterpene synthases of Coriandrum sativum L.

Terpenoids are a large and diverse class of specialized metabolites that are essential for the growth and development of plants, and have tremendous industrial applications. The mericarps of Coriandrum sativum L. (coriander) produce an essential oil (EO) rich in monoterpenes, volatile C10 terpenoids.

Cloning of a sesquiterpene synthase from Lavandula x intermedia glandular trichomes.

The essential oil (EO) of Lavandula is dominated by monoterpenes, but can also contain small amounts of sesquiterpenes, depending on species and environmental conditions. For example, the sesquiterpene 9-epi-caryophyllene can make up to 8 % of the EO in a few species, including those commercially propagated for EO production. Here, we report the cloning and functional characterization of 9-epi-caryophyllene synthase (LiCPS) from the glandular trichomes of Lavandula x intermedia, cv.

The biosynthetic origin of irregular monoterpenes in Lavandula: isolation and biochemical characterization of a novel cis-prenyl diphosphate synthase gene, lavandulyl diphosphate synthase.

Lavender essential oils are constituted predominantly of regular monoterpenes, for example linalool, 1,8-cineole, and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including lavandulyl diphosphate synthase (LPPS)) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described.

Molecular cloning and functional characterization of borneol dehydrogenase from the glandular trichomes of Lavandula x intermedia.

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.

Cloning, functional characterization and genomic organization of 1,8-cineole synthases from Lavandula.

Several members of the genus Lavandula produce valuable essential oils (EOs) that are primarily constituted of the low molecular weight isoprenoids, particularly monoterpenes. We isolated over 8,000 ESTs from the glandular trichomes of L. x intermedia flowers (where bulk of the EO is synthesized) to facilitate the discovery of genes that control the biosynthesis of EO constituents.

Improving peppermint essential oil yield and composition by metabolic engineering.

Peppermint (Mentha × piperita L.) was transformed with various gene constructs to evaluate the utility of metabolic engineering for improving essential oil yield and composition. Oil yield increases were achieved by overexpressing genes involved in the supply of precursors through the 2C-methyl-D-erythritol 4-phosphate (MEP) pathway.

Cloning and functional characterization of β-phellandrene synthase from Lavandula angustifolia.

En route to building genomics resources for Lavandula, we have obtained over 14,000 ESTs for leaves and flowers of L. angustifolia, a major essential oil crop, and identified a number of previously uncharacterized terpene synthase (TPS) genes. Here we report the cloning, expression in E.

A genomics resource for investigating regulation of essential oil production in Lavandula angustifolia.

We are developing Lavandula angustifolia (lavender) as a model system for investigating molecular regulation of essential oil (a mixture of mono- and sesquiterpenes) production in plants. As an initial step toward building the necessary 'genomics toolbox' for this species, we constructed two cDNA libraries from lavender leaves and flowers, and obtained sequence information for 14,213 high-quality expressed sequence tags (ESTs). Based on homology to sequences present in GenBank, our EST collection contains orthologs for genes involved in the 1-deoxy-D: -xylulose-5-phosphate (DXP) and the mevalonic acid (MVA) pathways of terpenoid biosynthesis, and for known terpene synthases and prenyl transferases.

Suppression of linalool acetate production in Lavandula x intermedia.

Linalool acetate, one of the major constituent of several essential oils, is heat-labile and decomposes upon exposure to the high injector temperature during gas chromatography. Here we report the development of an improved method for detection of this compound by gas chromatography mass spectrometry (GCMS) using cold on-column injection of the sample. By using this sensitive method, it has been demonstrated that a lavandin (L.

Cosuppression of limonene-3-hydroxylase in peppermint promotes accumulation of limonene in the essential oil.

cDNA clones encoding limonene synthase and limonene-3-hydroxylase, both driven by the CaMV 35S promoter, were independently transformed into peppermint (Menthaxpiperita) to alter the production and disposition of (-)-limonene, the first committed intermediate of essential oil biosynthesis in this species. Although both genes were constitutively expressed in leaves of transformed plants, the corresponding enzyme activities were not significantly increased in the glandular trichome sites of essential oil biosynthesis; thus, there was no effect on oil yield or composition in the regenerated plants. Cosuppression of the hydroxylase gene, however, resulted in the accumulation of limonene (up to 80% of the essential oil compared to about 2% of the oil in wild type plants), without influence on oil yield.