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1.
Derivatives of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid (chrysanthemic acid) are classic natural pyrethroids discovered in pyrethrum plants and show insecticidal activity. Chrysanthemic acid, with two asymmetric carbons, has four possible stereoisomers, and most natural pyrethroids have the (1R,3R)-trans configuration. Interestingly, chrysanthemic acid–related structures are also found in insect sex pheromones; carboxylic esters of (1R,3R)-trans-(2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl)methanol (chrysanthemyl alcohol) have been reported from two mealybug species. In the present study, another ester of chrysanthemyl alcohol was discovered from the striped mealybug, Ferrisia virgata (Cockerell), as its pheromone. By means of gas chromatography–mass spectrometry, nuclear magnetic resonance spectrometry, and high-performance liquid chromatography analyses using a chiral stationary phase column and authentic standards, the pheromone was identified as (1S,3R)-(?)-cis-chrysanthemyl tiglate. The (1S,3R)-enantiomer strongly attracted adult males in a greenhouse trapping bioassay, whereas the other enantiomers showed only weak activity. The cis configuration of the chrysanthemic acid–related structure appears to be relatively scarce in nature, and this is the first example reported from arthropods.  相似文献   

2.
Cuticular wax, abdominal and cephalic extracts of foraging workers and males of Nannotrigona testaceicornis and Plebeia droryana, from the “Aretuzina” farm in São Simão, SP, Brazil, were analyzed by GC-MS. The principal constituents were hydrocarbons, terpenes, aldehydes, esters, steroids, alcohols, and fatty acids. Interspecific differences for both cuticular wax and cephalic extracts were found. The composition of cuticular wax and cephalic extracts was similar at the intraspecific level, with minor component differences between males and workers. Abdominal extracts differentiated sexes (male and worker) at the intraspecific and interspecific levels. The main chemical components in abdominal extracts of N. testaceicornis workers and males were geranylgeranyl acetate and (Z)-9-nonacosene, respectively. The principal components of abdominal extracts from P. droryana workers and males were tetradecanal and unsaturated fatty acids (linoleic and linolenic acids), respectively. A secondary alcohol, (S)-2-nonanol, was detected in Plebeia droryana males only, but not in workers. Preliminary field experiments showed that (S)-(+)-2-heptanol and (S)-(+)-2-heptanol/ (S)-(+)-2-nonanol (1:1) attracted workers of P. droryana, N. testaceicornis, and Frieseomelitta silvestrii. However, males did not respond suggesting that these compounds do not function as alarm or recruitment pheromones . In addition, racemic mixtures were inactive.  相似文献   

3.
Delta (Δ) 5 desaturase is a key enzyme for the biosynthesis of health-beneficial long chain polyunsaturated fatty acids such as arachidonic acid (ARA, C20:4n-6), eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) via the “desaturation and elongation” pathways. A full length Δ5 desaturase gene from Euglena gracilis (EgΔ5D) was isolated by cloning the products of polymerase chain reaction with degenerate oligonucleotides as primers, followed by 5′ and 3′ rapid amplification of cDNA ends. The whole coding region of EgΔ5D was 1,350 nucleotides in length and encoded a polypeptide of 449 amino acids. BlastP search showed that EgΔ5D has about 39 % identity with a Δ5 desaturase of Phaeodactylum tricornutum. In a genetically modified dihomo-gamma-linoleic acid (DGLA, C20:3n-6) producing Yarrowia lipolytica strain, EgΔ5D had strong Δ5 desaturase activity with DGLA to ARA conversion of more than 24 %. Functional dissection of its HPGG and HDASH motifs demonstrated that both motifs were important, but not necessary in the exact form as encoded for the enzyme activity of EgΔ5D. A double mutant EgΔ5D-34G158G with altered sequences within both HPGG and HDASH motifs was generated and exhibited Δ5 desaturase activity similar to the wild type EgΔ5D. Codon optimization of the N-terminal region of EgΔ5D-34G158G and substitution of the arginine with serine at residue 347 improved substrate conversion to 27.6 %.  相似文献   

4.
Atractylodes rhizome is widely used in traditional Chinese herbal medicine. Although the chemical composition of the root has been studied in detail, the oil content and fatty acid composition of the seeds of Atractylodes species have not been reported. Fatty acyl composition of seeds from Atractylodes lancea and A. macrocephala was determined by gas chromatography and mass spectrometry of fatty acid methyl esters and 3-pyridylcarbinol esters. The predominant fatty acid in the seeds of both species was linolenic acid, but the unusual acetylenic fatty acid, crepenynic acid (cis-9-octadecen-12-ynoic acid), was also observed at levels of 18% in A. lancea and 13–15% in A. macrocephala. Fatty acid content was 24% for the samples of A. lancea and 16–17% for samples from A. macrocephala. sn-1,3 regioselective lipase digestion of seed lipids revealed that crepenynic acid was absent from the sn-2 position of the seed triacylglycerol. Crepenynic acid was also found in the seed oil of Jurinea mollis at 24% and was not present in the sn-2 position of the TAG. A contrasting distribution of crepenynic acid was found in the oil of Crepis rubra, suggesting differences in crepenynic acid synthesis or TAG assembly between these species.  相似文献   

5.
Isoflavonoids are a characteristic family of natural products in legumes known to mediate a range of plant-biotic interactions. For example, in soybean (Glycine max: Fabaceae) multiple isoflavones are induced and accumulate in leaves following attack by Spodoptera litura (Lepidoptera: Noctuidae) larvae. To quantitatively examine patterns of activated de novo biosynthesis, soybean (Var. Enrei) leaves were treated with a combination of plant defense elicitors present in S. litura gut content extracts and L-α-[13C9, 15N]phenylalanine as a traceable isoflavonoid precursor. Combined treatments promoted significant increases in 13C-labeled isoflavone aglycones (daidzein, formononetin, and genistein), 13C-labeled isoflavone 7-O-glucosides (daidzin, ononin, and genistin), and 13C-labeled isoflavone 7-O-(6″-O-malonyl-β-glucosides) (malonyldaidzin, malonylononin, and malonylgenistin). In contrast levels of 13C-labeled flavones and flavonol (4′,7-dihydroxyflavone, kaempferol, and apigenin) were not significantly altered. Curiously, application of fatty acid-amino acid conjugate (FAC) elicitors present in S. litura gut contents, namely N-linolenoyl-L-glutamine and N-linoleoyl-L-glutamine, both promoted the induced accumulation of isoflavone 7-O-glucosides and isoflavone 7-O-(6″-O-malonyl-β-glucosides), but not isoflavone aglycones in the leaves. These results demonstrate that at least two separate reactions are involved in elicitor-induced soybean leaf responses to the S. litura gut contents: one is the de novo biosynthesis of isoflavone conjugates induced by FACs, and the other is the hydrolysis of the isoflavone conjugates to yield isoflavone aglycones. Gut content extracts alone displayed no hydrolytic activity. The quantitative analysis of isoflavone de novo biosynthesis, with respect to both aglycones and conjugates, affords a useful bioassay system for the discovery of additional plant defense elicitor(s) in S. litura gut contents that specifically promote hydrolysis of isoflavone conjugates.  相似文献   

6.
JH Kim  J Kim  Y Park 《Lipids》2012,47(9):855-863
The supplementation of conjugated linoleic acid (CLA) has been shown to improve endurance by enhancing fat oxidation during exercise in rodents and humans. This study was designed to investigate the isomer-specific effects of CLA on endurance capacity and energy metabolism in mice during exercise. Male 129Sv/J mice were divided into three dietary groups and fed treatment diet for 6 weeks; control, 0.5 % cis-9,trans-11 (c9,t11) CLA, or 0.5 % trans-10,cis-12 (t10,c12) CLA. Dietary t10,c12 CLA induced a significant increase in maximum running time and distance until exhaustion with a dramatic reduction of total adipose depots compared to a control group, but there were no significant changes in endurance with the c9,t11 CLA treatment. Serum triacylglycerol and non-esterified fatty acid concentrations were significantly lower in the t10,c12 fed mice after exercise compared to control and the c9,t11 CLA fed-animals. Glycogen contents in livers of the t10,c12 fed-mice were higher than those in control mice, concomitant with reduction of serum l-lactate level. There were no differences in non-exercise physical activity among all treatment groups. In addition, the mRNA expression levels of carnitine palmitoyl transferase 1β, uncoupling protein 2 and peroxisome proliferator-activated receptor δ (PPARδ) in skeletal muscle during exercise were significantly up-regulated by the t10,c12 CLA but not the c9,t11 CLA. These results suggest that the t10,c12 CLA is responsible for improving endurance exercise capacity by promoting fat oxidation with a reduction of the consumption of stored liver glycogen, potentially mediated via PPARδ dependent mechanisms.  相似文献   

7.
A series of well-defined novel amphiphilic temperature-responsive graft copolymers containing PCL analogues P(αClεCL-co-εCL) as the hydrophobic backbone, and the hydrophilic side-chain PEG analogues P(MEO2MA-co-OEGMA), designated as P(αClεCL-co-εCL)-g-P(MEO2MA-co-OEGMA) have been prepared via a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The composition and structure of these copolymers were characterized by 1H NMR and GPC analyses. The self-assembly behaviors of these amphiphilic graft copolymers were investigated by UV transmittance, a fluorescence probe method, dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses. The results showed that the graft copolymers exhibited the good solubility in water, and was given the low critical temperature (LCST) at 35(±1) °C, which closed to human physiological temperature. The critical micelle concentrations (CMC) of P(αClεCL-co-εCL)-g-P(MEO2MA-co-OEGMA) in aqueous solution were investigated to be 2.0 × 10?3, 9.1 × 10?4 and 1.5 × 10?3 mg·mL?1, respectively. The copolymer could self-assemble into sphere-like aggregates in aqueous solution with diverse sizes when changing the environmental temperature. The vial inversion test demonstrated that the graft copolymers could trigger the sol-gel transition which also depended on the temperature.  相似文献   

8.
In this study, we isolated and identified an aggregation-sex pheromone from Monochamus saltuarius, the major insect vector of the pine wood nematode in Korea. Adult males of M. saltuarius produce 2-undecyloxy-1-ethanol, which is known as an aggregation-sex pheromone in other Monochamus species. We performed field experiments to determine the attractiveness of the pheromone and other synergists. More M. saltuarius adult beetles were attracted to traps baited with the pheromone than to unbaited traps. Ethanol and (?)-α-pinene interacted synergistically with the pheromone. Traps baited with the pheromone + (?)-α-pinene +ethanol were more attractive to M. saltuarius adults than traps baited with the pheromone, (?)-α-pinene, or ethanol alone. Ipsenol, ipsdienol, and limonene were also identified as synergists of the aggregation-sex pheromone for M. saltuarius adults. In field experiments, the proportion of females was much higher in the beetles caught in traps than among the beetles emerging from naturally-infested logs in the laboratory. Our results suggest that a combination of aggregation-sex pheromone and synergists could be very effective for monitoring and managing M. saltuarius.  相似文献   

9.
Small catalase-related hemoproteins with a facility to react with fatty acid hydroperoxides were examined for their potential mono-oxygenase activity when activated using iodosylbenzene. The proteins tested were a Fusarium graminearum 41 kD catalase hemoprotein (Fg-cat, gene FGSG_02217), a Pseudomonas fluorescens Pfl01 catalase (37.5 kD, accession number WP_011333788.1), and a Mycobacterium avium ssp. paratuberculosis 33 kD catalase (gene MAP-2744c). 13-Hydroxy-octadecenoic acids (which are normally unreactive) were selected as substrates because these enzymes react specifically with the corresponding 13S-hydroperoxides (Pakhomova et al. 18:2559–2568, 5; Teder et al. 1862:706–715, 14). In the presence of iodosylbenzene Fg-cat converted 13S-hydroxy-fatty acids to two products: the 15,16-double bond of 13S-hydroxy α-linolenic acid was oxidized stereospecifically to the 15S,16R-cis-epoxide or the 13-hydroxyl was oxidized to the 13-ketone. Products were identified by UV, HPLC, LC–MS, NMR and by comparison with authentic standards prepared for this study. The Pfl01-cat displayed similar activity. MAP-2744c oxidized 13S-hydroxy-linoleic acid to the 13-ketone, and epoxidized the double bonds to form the 9,10-epoxy-13-hydroxy, 11,12-epoxy-13-hydroxy, and 9,10-epoxy-13-keto derivatives; equivalent transformations occurred with 9S-hydroxy-linoleic acid as substrate. In parallel incubations in the presence of iodosylbenzene, human catalase displayed no activity towards 13S-hydroxy-linoleic acid, as expected from the highly restricted access to its active site. The results indicated that with suitable transformation to Compound I, monooxygenase activity can be demonstrated by these catalase-related hemoproteins with tyrosine as the proximal heme ligand.  相似文献   

10.
Elicitation of plant defense signaling that results in altered emission of volatile organic compounds (VOCs) offers opportunities for protecting plants against arthropod pests. In this study, we treated potato, Solanum tuberosum L., with the plant defense elicitor cis-jasmone (CJ), which induces the emission of defense VOCs and thus affects the behavior of herbivores. Using chemical analysis, electrophysiological and behavioral assays with the potato-feeding aphid Macrosiphum euphorbiae, we showed that CJ treatment substantially increased the emission of defense VOCs from potatoes compared to no treatment. Coupled GC-electroantennogram (GC-EAG) recordings from the antennae of M. euphorbiae showed robust responses to 14 compounds present in induced VOCs, suggesting their behavioral role in potato/aphid interactions. Plants treated with CJ and then challenged with M. euphorbiae were most repellent to alate M. euphorbiae. Principal component analysis (PCA) of VOC collections suggested that (E)-2-hexenal, (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), (E)-β-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate (MeSA), CJ, and methyl benzoate (MeBA) were the main VOCs contributing to aphid behavioral responses, and that production of TMTT, (E)-β-farnesene, CJ, and DMNT correlated most strongly with aphid repellency. Our findings confirm that CJ can enhance potato defense against aphids by inducing production of VOCs involved in aphid-induced signalling.  相似文献   

11.
The specific and equivalent conductivity of the diluted aqueous solutions of diallyammonium polyelectrolytes, initial monomers (N,N-diallylammonium trifluoroacetate, N,N-diallyl-N-methylammonium trifluoroacetate, N,N-diallyl-N,N-dimethylammonium chloride), and also potassium trifluoroacetate and trifluoroacetic acid solutions are studied. The limiting ionic mobility of diallylammonium cations and trifluoroacetate anion are found. The regularities of concentration changes in the equivalent conductance of polyelectolytes solutions are established. The degree of dissociation of diallyammonium polymers is shown to depend both on the counterion nature and on the amine structure.  相似文献   

12.
We previously reported that the trans-18:2 fatty acid trans-10, cis-12 conjugated linoleic acid (t10,c12-CLA) stimulates mammary gland development independent of estrogen and its receptor. Given the negative consequences of dietary trans-fatty acids on various aspects of human health, we sought to establish whether other trans-fatty acids could similarly induce ovary-independent mammary gland growth in mice. Prepubertal BALB/cJ mice were ovariectomized at 21 days of age then were fed diets enriched with cis-9, trans-11 CLA (c9,t11-CLA), or mixtures of trans-18:1 fatty acids supplied by partially hydrogenated sunflower, safflower, or linseed oil. The resultant mammary phenotype was evaluated 3 weeks later and compared to the growth response elicited by t10,c12-CLA, or the defined control diet. Whereas partially hydrogenated safflower oil increased mammary gland weight, none of the partially hydrogenated vegetable oils promoted mammary ductal growth. Similarly, the c9,t11-CLA supplemented diet was without effect on mammary development. Taken together, our data emphasize a unique effect of t10,c12-CLA in stimulating estrogen-independent mammary gland growth manifest as increased mammary ductal area and elongation that was not recapitulated by c9,t11-CLA or the partially hydrogenated vegetable oil diets.  相似文献   

13.
Mesoporous nickel oxide (NiO) nanoparticles were synthesized by the thermal decomposition reaction of Ni(NO3)2·9H2O using oxalic acid dihydrate as the mesoporous template reagent. The pore structure of nanocrystals could be controlled by the precursor to oxalic acid dihydrate molar ratio, thermal decomposition temperature and thermal decomposition time. The structural characteristic and textural properties of resultant nickel oxide nanocrytals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption–desorption isotherm and temperature programmed reduction. The results showed that the most excellently mesoporous nickel oxide particles (m-Ni-1-4) with developed wormlike pores were prepared under the conditions of the mixed equimolar precursor and oxalic acid and calcined for 4 h at 400 °C. The specific surface area and pore volume of m-Ni-1-4 are 236 m2 g?1 and 0.42 cm3 g?1, respectively. Over m-Ni-1-4 at space velocity = 20,000 mL g?1 h?1, the conversions of toluene and formaldehyde achieved 90 % at 242 and 160 °C, respectively. It is concluded that the reactant thermal decomposition with oxalic acid assist is a key step to improve the mesoporous quality of the nickel oxide materials, the developed mesoporous architecture, high surface area, low temperature reducibility and coexistence of multiple oxidation state nickel species for the excellent catalytic performance of m-Ni-1-4.  相似文献   

14.
Cholic acid is a class of biological compounds that exhibit valuable properties, and have been applied in many fields due to its special chemical structures for many areas. In this study, poly[(methacrylic acid tert-butyl cholate ester)-co-(acetoxy styrene)] [P(MATC-co-AS)] was synthesized from cholic acid, then the final copolymer poly[(methacrylic acid tert-butyl cholate ester)-co-(p-hydrostyrene)] [P(MATC-co-HS)] was obtained after P(MATC-co-AS) was hydrolysized. The structure and properties of the copolymers were determined through nuclear magnetic resonance, gel permeation chromatography, UV spectrometry, thermogravimetric analysis, and differential scanning calorimetry. The ultraviolet spectra of the copolymers indicate that they exhibit excellent optical transmittance at 248 nm. Moreover, the photolithography performance of a positive-tone photoresist based on the copolymers were evaluated using an KrF laser exposure system. The results indicate that a resolution of 0.25 μm could be achieved at a low exposure dose.  相似文献   

15.
L-lactic acid, as a monomer of polylactic acid, has attracted much attention because of the growing market for biodegradable bioplastics to reduce landfill waste. As an industrial L-lactic acid producer, Saccharomyces cerevisiae is generally used because it survives in low pH. However, in S. cerevisiae, production of L-lactic acid causes a decrease in intracellular pH, which leads to slow glycolytic flux, and consequently results in a lower productivity of L-lactic acid. For this reason, yeast strains that maintain their growth and the activities of metabolic enzymes during lactic acid production need to be developed for industrial applications. Herein, acid stable enzymes from acidophilic archaea Picrophilus torridus were expressed in L-lactic acid producing S. cerevisiae to increase glycolytic flux at low intracellular pH conditions for a higher L-lactic acid titer. Enzymes of lower glycolysis including phosphoglycerate kinase, phosphoglycerate mutase, enolase, and pyruvate kinase from P. torridus were introduced to develop a novel L-lactic acid producing strain. It was clearly shown that the production of lactic acid in the developed strain increased by 20% compared to the parental strain. To the best of our knowledge, this is the first report of P. torridus enzymes used in metabolic engineering to enhance the metabolic flux at a lower intracellular pH. Moreover, it is expected that the new strain will have an enhanced glycolytic flux at a low pH expressing acid stable enzymes that could be used to produce other valuable organic acids with increased titers.  相似文献   

16.
Vernolic acid (cis-12,13-epoxy-cis-9-oetadece-noic acid) occurs as the triglyceride in the seed ofVernonia anthelmintica. Incubation of the seed produces a 1,3-divernolin. To determine whether the structure of trivernolin is responsible for the apparent secondary ester position specificity of the natural enzyme, trivernolin and tri-olein, were incubated with pancreatic lipase and the free fatty acids and monoglycerides were determined after 5 and 15 min digestion periods. The preponderance of 2-monoglyceride produced by the action of pancreatic lipase was interpreted to indicate that the structure of trivernolin was not solely responsible for the secondary position specificity of theV. anthelmintica lipase toward trivernolin.  相似文献   

17.
The fatty acid composition of 27 samples of commercial hydrogenated vegetable oils and 23 samples of refined oils such as sunflower oil, rice bran oil, soybean oil and RBD palmolein marketed in India were analyzed. Total cis, trans unsaturated fatty acids (TFA) and saturated fatty acids (SFA) were determined. Out of the 27 hydrogenated fats, 11 % had TFA about 1 % where as 11 % had more than 5 % TFA with an average value of about 13.1 %. The 18:1 trans isomers, elaidic acid was the major trans contributor found to have an average value of about 10.8 % among the fats. The unsaturated fatty acids like cis-oleic acid, linoleic acid and α-linolenic acid were in the range of 21.8–40.2, 1.9–12.2, 0.0–0.7 % respectively. Out of the samples, eight fats had fatty acid profiles of low TFA (less than 10 %) and high polyunsaturated fatty acids (PUFA) such as linoleic and α-linolenic acid. They had a maximum TFA content of 7.3 % and PUFA of 11.7 %. Among the samples of refined oils, rice bran oil (5.8 %) and sunflower oil (4.4 %) had the maximum TFA content. RBD palmolein and rice bran oils had maximum saturated fatty acids content of 45.1 and 24.4 % respectively. RBD palmolein had a high monounsaturated fatty acids (MUFA) content of about 43.4 %, sunflower oil had a high linoleic acid content of about 56.1 % and soybean oil had a high α-linolenic acid content of about 5.3 %.  相似文献   

18.
The stability of anionic-cationic surfactant solutions and the antimicrobial properties of novel N,N-dimethyl-N-[3-(gluconamide/lactobionamide)]propyl-N-alkylammonium bromides (CnDGPB and CnDLPB), N-methyl-N-hydroxyethyl group-N-[3-(gluconamide)-propyl]-N-alkylammonium bromide (CnMHGPB) and star-shaped gluconamide-type cationic surfactants N-dodecyl-N,N-bis[(3-d-gluconylamido)propyl]-N-alkylammonium bromide (CnDBGB) were investigated. Mixed stability in combination with sodium n-alkylbenzenesulfonate (LAS) was determined via transmittance; stability is achieved when percent transmittance was greater than 90 %. Transmittance results suggest that these cationic surfactants can form stable solutions with anionic surfactants over a broad concentration range. The inhibition activity of C n DBGB is the best among the three kinds of glucocationic surfactants. Antimicrobial activity of C12 surfactants was the best, C14 was the second and C10 was the worst. Moreover, antibacterial activity of glucose-based cationic surfactants was greater than lactose-based cationic surfactants.  相似文献   

19.
Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of interest because it is the primary vector of the causal pathogen of citrus greening disease. Non-pesticidal control methods for D. citri remain a high priority for the citrus industry. While searching for semiochemicals that may be involved in orientation to host plants, we previously identified a blend of formic and acetic acids that stimulated substrate probing by D. citri. Here, we applied geometric mixture designs and response surface modeling to identify and optimize a 3-component blend that further increased the number of salivary sheaths produced by D. citri on a wax substrate containing a 3.5:1.6:1 blend of formic acid, acetic acid, and p-cymene, respectively. No evidence was found for remote orientation by D. citri adults through olfaction to the phagostimulant blends. Increased probing in response to the presence of phagostimulants in the wax matrix occurred after contact with the substrate. Yellow wax beads always attracted more D. citri adults and received more probes compared with white wax beads. Yellow beads containing the 3-component blend of phagostimulants were probed by D. citri 2 to 3 times more often compared with yellow beads alone. The phagostimulant effect also was tested by covering wax beads containing the 3-component blend with a plastic film to minimize olfaction or contact chemoreception by antennation. The plastic film did not affect the probing response, thus suggesting that chemosensation was associated with mouthparts and not olfactory receptors. Salivary sheaths produced in wax beads containing the phagostimulant blend were 4.5 times longer than sheaths produced in beads without tastants. This phenomenon might be used to improve a trap, design an attract-and-kill product, or enhance other means of managing D. citri and citrus greening disease.  相似文献   

20.
Diaphorina citri is a vector of the bacterial causative agent of Huanglongbing (HLB?=?Citrus greening), a severe disease affecting citrus crops. As there is no known control for HLB, manipulating insect behaviour through deployment of semiochemicals offers a promising opportunity for protecting citrus crops. The behavioural responses of D. citri to plant volatiles, and the identity of these plant volatiles were investigated. Volatiles were collected from host plants Murraya paniculata, Citrus sinensis, C. reshni, C. limettioides, Poncirus trifoliata, and from non-host plants Psidium guajava, Mangifera indica, Anacardium occidentale. In behavioural assays, female D. citri spent more time in the arms containing volatiles from either M. paniculata or C. sinensis compared to the control arms. When D. citri was exposed to volatiles collected from A. occidentale, they preferred the control arm. Volatiles emitted from the other studied plants did not influence the foraging behaviour of D. citri. Chemical analyses of volatile extracts from C. sinensis, M. paniculata, and A. occidentale revealed the presence of the terpenoids (E)-4,8-dimethylnona-1,3,7–triene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in higher amounts in A. occidentale. In further behavioural bioassays, female D. citri spent less time in arms containing a synthetic blend of DMNT and TMTT compared to the control arms. Female D. citri also spent less time in arms containing the synthetic blend in combination with volatile extracts from either M. paniculata or C. sinensis compared to the control arms. Results suggest that higher release of the two terpenoids by A. occidentale make this species unattractive to D. citri, and that the terpenoids could be used in reducing colonisation of citrus plants and therefore HLB infection.  相似文献   

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