caryophyllene and jasmonic-acid

The effect of exogenous application of jasmonic acid (JA) on the concentration of main terpenes and density of glandular trichomes was investigated in the Mexican oregano, propagated from seeds from 3 localities. JA 1 mM was applied locally and to the whole plant. JA locally applied increased the number of trichomes, with a mean of 20 trichomes more with respect to the controls in plants from Tecomavaca and Zapotitlán Salinas, and significantly increased the thymol concentration by 185% systemically and 255% locally, compared to the control. JA applied to the whole plant decreased the number of trichomes and increased the concentration of caryophyllene from 0.79 to 1.7 mg g

Topics: Cyclopentanes; Lippia; Mexico; Monocyclic Sesquiterpenes; Monoterpenes; Origanum; Oxylipins; Polycyclic Sesquiterpenes; Terpenes; Thymol; Trichomes; Verbenaceae

The aim of the present study was to determine the effect of jasmonic acid added to the culture medium on composition of Lavandula angustifolia essential oils. The chemical composition was determined by gas chromatography coupled to mass detector (GC/MS). The experiment was conducted with the use of MS medium supplemented with increasing concentration of JA (0.2, 0.5, 1, 1.5 mg∙dm

Topics: Acetates; Acyclic Monoterpenes; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Cell Culture Techniques; Culture Media; Cyclohexanols; Cyclopentanes; Eucalyptol; Gas Chromatography-Mass Spectrometry; Lavandula; Monoterpenes; Oils, Volatile; Oxylipins; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes

Insect resistance against root herbivores like the western corn rootworm (WCR, Diabrotica virgifera virgifera) is not well understood in non-transgenic maize. We studied the responses of two American maize inbreds, Mp708 and Tx601, to WCR infestation using biomechanical, molecular, biochemical analyses, and laser ablation tomography. Previous studies performed on several inbreds indicated that these two maize genotypes differed in resistance to pests including fall armyworm (Spodoptera frugiperda) and WCR. Our data confirmed that Mp708 shows resistance against WCR, and demonstrates that the resistance mechanism is based in a multi-trait phenotype that includes increased resistance to cutting in nodal roots, stable root growth during insect infestation, constitutive and induced expression of known herbivore-defense genes, including ribosomal inhibitor protein 2 (rip2), terpene synthase 23 (tps23) and maize insect resistance cysteine protease-1 (mir1), as well high constitutive levels of jasmonic acid and production of (E)-β-caryophyllene. In contrast, Tx601 is susceptible to WCR. These findings will facilitate the use of Mp708 as a model to explore the wide variety of mechanisms and traits involved in plant defense responses and resistance to herbivory by insects with several different feeding habits.

Topics: Alkyl and Aryl Transferases; Animals; Coleoptera; Cyclopentanes; Gene Expression Regulation, Plant; Herbivory; Oxylipins; Plant Proteins; Plant Roots; Polycyclic Sesquiterpenes; RNA, Plant; Sesquiterpenes; Zea mays

Various pests, such as those in the order Lepidoptera, frequently feed on young maize (Zea mays) plants and pose a significant threat to plant development and survival. To manage this problem, maize generates a wide variety of responses to attack by pests, from activation of wound-response pathways to the release of volatile compounds. Mp708, an inbred line resistant to feeding by the larvae of the fall armyworm (Spodoptera frugiperda J.E. Smith Lepidoptera: Noctuidae), has been developed through traditional breeding methods, but its underlying mechanisms of resistance are still not completely understood. Mp708 has been shown to have a moderately high constitutive expression of jasmonic acid (JA) before infestation by fall armyworm. However, Tx601, a genotype susceptible to feeding by fall armyworm, activates JA pathway only in response to feeding, suggesting that Mp708 is "primed" to respond swiftly to an attack. Current research indicates that fall armyworm show a lack of preference to feeding on Mp708, leading to the hypothesis that volatiles constitutively released by the plant may also play an important role in its resistance. Analysis of volatiles released by Mp708 and Tx601 in the presence and absence of fall armyworm larvae identified (E)-beta-caryophyllene, a terpenoid associated with resistance, released constitutively in Mp708. Fall armyworm fed samples of both Mp708 and Tx601 showed high transcript number of tps23, the gene responsible for the synthesis of (E)-beta-caryophyllene. In addition, fall armyworm larvae show a preference for Tx601 whorl tissue over Mp708 tissue, and the dosage of Tx601 whorl with (E)-beta-caryophyllene repels the fall armyworm.

Topics: Alkyl and Aryl Transferases; Animals; Cyclopentanes; Food Preferences; Herbivory; Larva; Oxylipins; Plant Leaves; Polycyclic Sesquiterpenes; Real-Time Polymerase Chain Reaction; Sesquiterpenes; Spodoptera; Zea mays

Arabidopsis thaliana flowers emit volatile terpenes, which may function in plant-insect interactions. Here, we report that Arabidopsis MYC2, a basic helix-loop-helix transcription factor, directly binds to promoters of the sesquiterpene synthase genes TPS21 and TPS11 and activates their expression. Expression of TPS21 and TPS11 can be induced by the phytohormones gibberellin (GA) and jasmonate (JA), and both inductions require MYC2. The induction of TPS21 and TPS11 results in increased emission of sesquiterpene, especially (E)-β-caryophyllene. DELLAs, the GA signaling repressors, negatively affect sesquiterpene biosynthesis, as the sesquiterpene synthase genes were repressed in plants overaccumulating REPRESSOR OF GA1-3 (RGA), one of the Arabidopsis DELLAs, and upregulated in a penta DELLA-deficient mutant. Yeast two-hybrid and coimmunoprecipitation assays demonstrated that DELLAs, represented by RGA, directly interact with MYC2. In yeast cells, the N terminus of MYC2 was responsible for binding to RGA. MYC2 has been proposed as a major mediator of JA signaling and crosstalk with abscisic acid, ethylene, and light signaling pathways. Our results demonstrate that MYC2 is also connected to GA signaling in regulating a subset of genes. In Arabidopsis inflorescences, it integrates both GA and JA signals into transcriptional regulation of sesquiterpene synthase genes and promotes sesquiterpene production.

Topics: Alkyl and Aryl Transferases; Arabidopsis; Arabidopsis Proteins; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Cyclopentanes; Gene Expression Regulation, Plant; Gibberellins; Inflorescence; Light; Mutation; Oxylipins; Plants, Genetically Modified; Polycyclic Sesquiterpenes; Promoter Regions, Genetic; Repressor Proteins; Sesquiterpenes; Signal Transduction; Two-Hybrid System Techniques

Induced plant responses to insect attack include the release of volatile chemicals. These volatiles are used as host-location signals by foraging parasitoids, which are natural enemies of insect herbivores. A plant's response to herbivory can be influenced by factors present in insect oral secretions. Volicitin (N-(17-hydroxylinolenoyl)-L-glutamine), identified in beet armyworm (Spodoptera exigua) oral secretions, stimulates volatile release in corn (Zea mays L.) seedlings in a manner similar to beet armyworm herbivory. Volicitin is hypothesized to trigger release of induced volatiles, at least in part, by modulating levels of the wound hormone, jasmonic acid (JA). We compare the sesquiterpene volatile release of damaged leaves treated with aqueous buffer only or with the same buffer containing volicitin or JA. Leaves were damaged by scratching with a razor and test solutions were applied to the scratched area. The leaves were either excised from the plant or left intact shortly after this treatment. Plants were treated at three different times (designated as Evening, Midnight, and Morning) and volatiles were collected in the subsequent photoperiod. JA and volicitin treatments stimulated the release of volatile sesquiterpenes, namely beta-caryophyllene, (E)-alpha-bergamotene, and (E)-beta-farnesene. In all cases, JA stimulated significant sesquiterpene release above mechanical damage alone. Volicitin induced an increase in sesquiterpene volatiles for all excised-leaf bioassays and the Midnight intact plants. Volicitin treatments in the Evening and Morning intact plants produced more sesquiterpenes than the untreated controls, while mechanical damage alone produced an intermediate response that did not differ from either treatment group. Excised leaves produced a 2.5- to 8.0-fold greater volatile response than similarly treated intact plants. Excision also altered the ratio of JA-and volicitin-induced sesquiterpene release by preferentially increasing (E)-beta-farnesene levels relative to beta-caryophyllene. The inducibility of volatile release varied with time of treatment. On average, sesquiterpene release was highest in the Midnight excised leaves and lowest in the Morning intact plants. The duration of induced volatile release also differed between treatments. On average, JA produced a sustained release of sesquiterpenes over time, with over 20% of the combined sesquiterpenes released in the third and final volatile collection period. In contrast, less

Topics: alpha-Linolenic Acid; Animals; Biological Assay; Bridged Bicyclo Compounds; Cyclopentanes; Glutamine; Host-Parasite Interactions; Oxylipins; Plant Leaves; Plants; Polycyclic Sesquiterpenes; Sesquiterpenes; Signal Transduction; Spodoptera; Time Factors; Volatilization; Zea mays