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1.
Food Chem ; 335: 127512, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32745837

RESUMO

To reveal the potential of core bacterial and fungal communities for aroma formation in the fermentation of chili pepper, shifts in microbial diversity and volatile metabolites during the 32-day fermentation process were measured using high-throughput sequencing and gas chromatography-mass spectrometry. Rosenbergiella and Staphylococcus were the dominant bacterial genera, where Hyphopichia and Kodamaea were the most abundant fungi, in fermented chili pepper. Sixteen differential volatile metabolites were detected in fermented and unfermented samples using differential metabolomics analysis. Nine strains from the genera Hyphopichia, Staphylococcus, Rosenbergiella, and Bacillus were isolated from fermented chili pepper. The correlation of dominant microorganisms with key odorants by Spearman correlation and two-way orthogonal partial least squares analysis indicated that Hyphopichia exhibited a significant positive correlation with the formation of 11 key odorants. These findings enhance our understanding of the core functional bacterial and fungal genera involved in the production of desirable flavors in fermented chili pepper.


Assuntos
Bactérias/metabolismo , Biodiversidade , Capsicum/metabolismo , Capsicum/microbiologia , Fermentação , Compostos Orgânicos Voláteis/metabolismo , Bactérias/classificação , Paladar
2.
Int J Food Microbiol ; 334: 108839, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32906081

RESUMO

Flavourzyme is known to promote protein decomposition, resulting in more peptides and amino acids which can improve the quality of fermented foods. In this study, the effects of flavourzyme addition on the fermentation of Suanzhayu fish were investigated. The results showed that the addition of 50 U/g flavourzyme reduced the water activity (aw) of products and promoted the release of trichloroacetic acid (TCA)-soluble peptides and free amino acids (FAAs). Thus, the stability of the product was improved and its nutritional value was increased. In addition, with the addition of flavourzyme, Lactobacillus and Saccharomyces more quickly became the dominant genera in the fermentation. Furthermore, the formation of alcohols, aldehydes, and esters was promoted in flavourzyme addition group. Redundant analysis (RDA) indicated that Lactobacillus and Lactococcus play important roles in the formation of flavors, especially for the characteristic flavors of Suanzhayu. Flavourzyme addition may be a novel method to greatly improve the properties of Suanzhayu and shorten the fermentation time.


Assuntos
Endopeptidases/metabolismo , Alimentos e Bebidas Fermentados , Peixes , Microbiota , Compostos Orgânicos Voláteis/química , Aminoácidos/metabolismo , Animais , Fermentação , Alimentos e Bebidas Fermentados/análise , Alimentos e Bebidas Fermentados/microbiologia , Lactobacillales/classificação , Lactobacillales/metabolismo , Peptídeos/metabolismo , Saccharomyces/metabolismo , Paladar , Compostos Orgânicos Voláteis/metabolismo
3.
Sci Rep ; 10(1): 11746, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678173

RESUMO

Category A and B biothreat agents are deemed to be of great concern by the US Centers for Disease Control and Prevention (CDC) and include the bacteria Francisella tularensis, Yersinia pestis, Burkholderia mallei, and Brucella species. Underscored by the impact of the 2020 SARS-CoV-2 outbreak, 2016 Zika pandemic, 2014 Ebola outbreak, 2001 anthrax letter attacks, and 1984 Rajneeshee Salmonella attacks, the threat of future epidemics/pandemics and/or terrorist/criminal use of pathogenic organisms warrants continued exploration and development of both classic and alternative methods of detecting biothreat agents. Volatile organic compounds (VOCs) comprise a large and highly diverse group of carbon-based molecules, generally related by their volatility at ambient temperature. Recently, the diagnostic potential of VOCs has been realized, as correlations between the microbial VOC metabolome and specific bacterial pathogens have been identified. Herein, we describe the use of microbial VOC profiles as fingerprints for the identification of biothreat-relevant microbes, and for differentiating between a kanamycin susceptible and resistant strain. Additionally, we demonstrate microbial VOC profiling using a rapid-throughput VOC metabolomics method we refer to as 'simultaneous multifiber headspace solid-phase microextraction' (simulti-hSPME). Finally, through VOC analysis, we illustrate a rapid non-invasive approach to the diagnosis of BALB/c mice infected with either F. tularensis SCHU S4 or Y. pestis CO92.


Assuntos
Metabolômica/métodos , Tularemia/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Animais , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Surtos de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Feminino , Francisella tularensis/efeitos dos fármacos , Francisella tularensis/isolamento & purificação , Francisella tularensis/metabolismo , Canamicina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Microextração em Fase Sólida , Tularemia/microbiologia , Tularemia/patologia , Tularemia/veterinária , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Yersinia pestis/efeitos dos fármacos , Yersinia pestis/isolamento & purificação , Yersinia pestis/metabolismo
4.
PLoS One ; 15(7): e0235630, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32628739

RESUMO

In several phytophagous hemipterans, behavior appears to be mediated by both visual and chemical cues. For the Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera: Liviidae), olfactometric assays are generally difficult to interpret owing to the low proportion of individuals responding to odors (~30-40%), which compromises the efficiency and reliability of the results of behavioral tests. In the present study, the ACP behavioral response to emitted odors from sweet orange (Citrus sinensis L. Osbeck) flushes in a 4-arm olfactometer using different colors (four white-, two white- and two yellow- on opposite sides, or four yellow-colored fields), and the role of the airflow in the concentration of volatile organic compounds (VOCs) were assessed at two airflows [0.4 and 0.1 L/min (LPM)]. Exposure to 'Pera' sweet orange or clean air in treatments with four yellow-colored-fields increased the response rate of ACP females to the odor sources compared with exposure to 'Pera' sweet orange or clean air in treatments with four white-colored-fields, independently of the odor source and airflow tested. For the assays using two white- and two yellow-colored fields on opposite sides and 0.4 or 0.1 LPM airflow, the residence time of ACP females to odors ('Pera' sweet orange or clean air) was similar or higher in treatments using yellow- than those using white-colored fields. For both assays (VOCs and olfactometric behavioral parameters), the reduction in airflow from 0.4 to 0.1 LPM greatly changed the airborne concentration and ACP behavior. Quantitative chemical analyses revelead that the concentration of most compounds emitted by 'Pera' sweet orange flushes for the headspace using 0.1 LPM airflow were greater than the concentrations measured using 0.4 LPM airflow. Therefore, this treatment design provides an useful tool to assess the ACP behavioral response to the odors from citrus plants, and it can also help in the discrimination of dose-response screenings for VOCs or conspecific insects.


Assuntos
Ar , Comportamento Animal/efeitos dos fármacos , Citrus/metabolismo , Hemípteros/efeitos dos fármacos , Hemípteros/fisiologia , Olfato , Compostos Orgânicos Voláteis/farmacologia , Animais , Cor , Relação Dose-Resposta a Droga , Compostos Orgânicos Voláteis/metabolismo
5.
J Food Sci ; 85(7): 2069-2079, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32602125

RESUMO

Triggered by the development of lactic acid bacteria (LAB) during the production of Scotch whisky, this study examined the influence of yeast and LAB inoculation on whisky flavor. Four new spirits were produced using the same process. LAB were added as a form of a Greek yogurt's live culture. In each category (barley and rye), one sample was fermented with Greek yogurt while the other was fermented without it. The spirits were matured and analyzed at five different points. Results from gas chromatography-mass spectrometry (GC-MS) analysis showed basic volatile compounds, along with some important extra compounds with yogurt culture. The most obvious differences were observed in the concentration of butanoic acid, a characteristic acid in spirits undergoing lactic acid fermentation: to identify esters such as ethyl butanoate, ethyl isobutanoate, isoamyl butanoate, and 2-phenylethyl butanoate, they are not typical compounds in whisky.


Assuntos
Bebidas Alcoólicas/análise , Aromatizantes/química , Manipulação de Alimentos/métodos , Iogurte/análise , Bebidas Alcoólicas/microbiologia , Meios de Cultura/análise , Meios de Cultura/metabolismo , Fermentação , Aromatizantes/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hordeum/metabolismo , Hordeum/microbiologia , Humanos , Lactobacillales/metabolismo , Odorantes/análise , Secale/metabolismo , Secale/microbiologia , Paladar , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Leveduras/metabolismo , Iogurte/microbiologia
6.
Food Chem ; 333: 127549, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683266

RESUMO

Enzymatic tenderization is extensively applied in the meat industry, whereas its influence on meat flavor has seldom been evaluated. Proteinase K, papain, bromelain and Flavourzyme® were used to treat beef muscle, and the changes in volatile compounds and odors were subsequently analyzed. Proteolysis by proteinase K was found to elevate the average bitterness of the identified peptides by generating peptides with high Q values, whereas proteolysis by papain generated the highest level of amino acids. Enzymatic treatment by Flavourzyme and bromelain significantly elevated the levels of ketones and odors, whereas excessive proteolysis by papain and proteinase K largely reduced the levels of esters and aldehydes. The level of amino acids and degree of hydrolysis were found to be predominant factors that regulated the level of volatiles and odors. These results highlighted the huge influence of enzymatic tenderization on meat flavor, depending on degree of hydrolysis and cleavage pattern of applied proteases.


Assuntos
Proteínas Musculares/metabolismo , Odorantes , Peptídeo Hidrolases/metabolismo , Proteólise , Carne Vermelha/análise , Compostos Orgânicos Voláteis/metabolismo , Aminoácidos/metabolismo , Animais , Bovinos , Hidrólise , Paladar
7.
PLoS One ; 15(6): e0235442, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598404

RESUMO

In this study, we were challenging to identify characteristic compounds in breast cancer cell lines. GC analysis of extracts from the culture media of breast cancer cell lines (MCF-7, SK-BR-3, and YMB-1) using a solid-phase Porapak Q extraction revealed that two compounds of moderate volatility, 1-hexadecanol and 5-(Z)-dodecenoic acid, were detected with markedly higher amount than those in the medium of fibroblast cell line (KMST-6). Furthermore, LC-TOF/MS analysis of the extracts clarified that in addition to the above two fatty acids, the amounts of five unsaturated fatty acids [decenoic acid (C10:1), decadienoic acid (C10:2), 5-(Z)-dodecenoic acid (C12:1), 5-(Z)-tetradecenoic acid (C14:1), and tetradecadienoic acid (C14:2)] in MCF-7 medium were higher than those in medium of KMST-6. Interestingly, H2O2-oxidation of 5-(Z)-dodecenoic acid and 5-(Z)-tetradecenoic acid produced volatile aldehydes that were reported as specific volatiles in breath from various cancer patients, such as heptanal, octanal, nonanal, decanal, 2-(E)-nonenal, and 2-(E)-octenal. Thus, we concluded that these identified compounds over-produced in breast cancer cells in this study could serve as potential precursors producing reported cancer-specific volatiles.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ácidos Graxos/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Ácidos Graxos/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Oxirredução , Microextração em Fase Sólida , Células Tumorais Cultivadas , Compostos Orgânicos Voláteis/análise
8.
Food Chem ; 330: 127316, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569933

RESUMO

Dynamics of microbial community and changes of metabolites during production of type Ι sourdough steamed bread made by retarded sponge-dough method (SSB) were studied. Lactobacillus sanfranciscensis and Lactobacillus pontis were the dominant bacterial species. Particularly, relative abundances of Lactobacillus sanfranciscensis were significantly higher than that of other sub-dominant bacterial species. The dominant fungal species were Saccharomyces cerevisiae and Kazachstania humilis, and the latter was the most predominant. A stable bacterial and fungal consortia was established in sponge dough retarded from 12 to 24 h and main dough proofed from 30 to 60 min. Metabolism preference for maltose of Lactobacillus sanfranciscensis favoured a mutualistic association with maltose-negative Kazachstania humilis, and hence contributing to their competitiveness and dominance. Volatile compounds became more abundant with much more esters as sponge retarding time extended. Probably, the accumulation of organic acids and ethanol contributed mostly to formation of ethyl esters in sponge dough during retarding.


Assuntos
Pão/microbiologia , Microbiota , Pão/análise , Fermentação , Microbiologia de Alimentos , Lactobacillus/genética , Lactobacillus/metabolismo , Maltose/metabolismo , Microbiota/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Vapor , Simbiose , Compostos Orgânicos Voláteis/metabolismo
9.
Food Chem ; 331: 127286, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32562978

RESUMO

Nowadays, novel tools have been developed for efficient analysis and visualization of large-scale metabolite profile data associated with metabolic pathways. A high-throughput platform using PathVisio 3 combined with multivariate analysis is proposed for the first time. Additionally, this is the first analysis of the relationships among terpenoids monoterpene, sesquiterpene, triterpene, and tetraterpene during pepper fruit ripening, and their changes. This platform was successfully applied to interpret large-scale data related to 131 metabolites from mature and immature fruits of 13 pepper phenotypes. The carotenoid-derived volatiles, such as dihydroactinidiolide and ß-ionone were closely correlated with carotenoids, indicating that the synthesis and degradation of carotenoids occurred in pepper fruit mature stage. Using PathVisio 3, the metabolic changes in pathway could be presented quickly, revealing the accumulation of stress-related metabolites, such as proline, capsaicin, and phenylalanine, in the mature stage. This approach could provide useful information about comprehensive biochemical regulation of fruit ripening.


Assuntos
Capsicum/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Metabolômica/métodos , Capsaicina/análise , Capsaicina/metabolismo , Capsicum/química , Capsicum/crescimento & desenvolvimento , Carotenoides/análise , Carotenoides/metabolismo , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Ensaios de Triagem em Larga Escala , Metabolômica/estatística & dados numéricos , Análise Multivariada , Fenótipo , Terpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
10.
J Oleo Sci ; 69(7): 759-765, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32522943

RESUMO

The current investigation reports the chemical composition of volatile organic compounds emitted from the different aerial organs of two populations of Salvia dominica L. from Jordan collected from Mediterranean and Irano-Turanian bio-geographical zones. Oxygenated monoterpenes dominated the emission profiles of most organs from the two populations but with variable qualitative and quantitative differences. Mediterranean samples contained higher content of oxygenated monoterpenes (stems: 88.37%, leaves 89.95%, pre-flowering buds 67.14%, fully opened flowers 79.43%, sepals 90.93% and petals 92.25%) as compared to those from Irano-Turanian origin (range 39.85% to 75.06%). trans-Sabinene hydrate dominated the emission profiles of all organs from Irano-Turanian zone (range 38.54% to 73.24%) in addition to the stem, sepal and petal samples from the Mediterranean zone (51.37% to 86.98%). The other organs from the Mediterranean zone were dominated by α-terpenyl acetate (27.66-54.87%). Cluster and Principle Component statistical analysis classified the two populations into two clusters based on their origin. The current study evidenced the different VOCs composition in the two populations, that was mainly related to climatic and environmental conditions and suggested the presence of two ecotypes of S. dominica L.in Jordan.


Assuntos
Monoterpenos Bicíclicos/metabolismo , Monoterpenos/metabolismo , Salvia/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Monoterpenos Bicíclicos/análise , Clima , Meio Ambiente , Jordânia , Monoterpenos/análise , Oxirredução , Salvia/anatomia & histologia , Salvia/classificação
11.
J Breath Res ; 14(4): 046002, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32512549

RESUMO

Volatile organic compounds (VOCs) emitted by organisms and cell metabolism have demonstrated great physiological and pathological values. At present, there is a great interest in the study of volatile metabolome to determine whether VOCs can serve as potential diagnostic biomarkers. In view of the sensitivity of VOCs to physiological changes, the aim of this study was to investigate alterations in VOC profiles in the in vitro headspace of HepG2 cells after exposure to triclosan (TCS). Since the in vivo biological effects of TCS are clearly defined, several TCS-related VOCs may potentially be traced back to common cellular processes. In this study, HepG2 cells were cultured in TCS-containing medium for 2 h, and the emitted VOCs in the headspace of the culture flask were detected using a single photon ionization time-of-flight mass spectrometry instrument. The control group and the TCS-treated group could be well separated by differential VOC profiles, which were related to the physiological states of the HepG2 cells. Compared to the control group, eleven and ten specific VOCs were identified in the 20 µm and 50 µm TCS-treated groups, respectively. Among them, five specific VOCs (m/z 62, 64, 70, 121 and 146) were commonly observed in these two TCS-treated groups. These results indicate that TCS can cause changes in cellular metabolic VOCs, and different concentrations of TCS lead to different VOCs profiles. Based on the findings of the study, the detection of VOCs in cell metabolism can be used as an auxiliary tool to explore the mechanism of drug action, and also as an exploratory method to determine whether drugs play a role in disease treatment.


Assuntos
Espectrometria de Massas/métodos , Triclosan/farmacologia , Compostos Orgânicos Voláteis/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Glutationa/metabolismo , Células Hep G2 , Humanos , Metaboloma , Peso Molecular , Reprodutibilidade dos Testes
12.
Chemosphere ; 256: 127093, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470731

RESUMO

Bio-trickling filters (BTFs) can be used for the treatment of hydrophobic VOC-contaminated air. To improve treatment performance, two novel polydimethylsiloxane (PDMS) packing media were produced and trialled in BTFs inoculated with Cladophialophora fungus. The BTF packed with PDMS/foam ceramic composite filler showed superior performance: rapid start-up within 3 days, rapid restart within 7 days after starvation for 1 month, a maximum toluene elimination capacity (EC) of 264.4 g m-3·h-1 at an empty bed residence time of 10 s, and a pressure drop that was controllable by adjusting the nutrient supply regime. High-throughput sequencing was used to analyse the effect of spatial position on the microbial communities in the top and bottom filler layers. Meanwhile, by investigating the EC in the vertical direction of the BTF, spatial heterogeneity in the fungal degradation of a hydrophobic VOC was preliminarily explored.


Assuntos
Biodegradação Ambiental , Reatores Biológicos , Siloxanas/química , Compostos Orgânicos Voláteis/metabolismo , Aerossóis , Poluentes Atmosféricos/metabolismo , Cerâmica , Dimetilpolisiloxanos , Filtração , Fungos/metabolismo , Tolueno , Compostos Orgânicos Voláteis/análise
13.
J Food Sci ; 85(6): 1642-1650, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32430953

RESUMO

The effects of different mucor strains (Mucor racemosus, Actinomucor, and Mucor wutungkiao) on aroma and taste profiles based on proteolysis, lipolysis, and their catabolism in oil furu were studied. Gas chromatography-mass spectrometry and relative odor activity were used to monitor the changes of key volatile compounds and the differences in the characteristic aroma contents of oil furu. Using principal component analysis, the different fermentation strains had an effect on aroma profiles. The volatile compounds from metabolism of protein and fatty acid contributed to the aroma of oil furu with different contribution from the different strains, presumably due to their different enzymes. The electronic tongue and free amino acid profiles also showed strain differences of taste. Based on these results, optimization of the amount of each of the different mucor strains during cofermentation might achieve better flavor.


Assuntos
Aromatizantes/química , Mucor/metabolismo , Odorantes/análise , Alimentos de Soja/microbiologia , Soja/química , Soja/microbiologia , Aminoácidos/química , Aminoácidos/metabolismo , Nariz Eletrônico , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Fermentação , Aromatizantes/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Mucorales/metabolismo , Alimentos de Soja/análise , Soja/metabolismo , Paladar , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo
14.
Food Chem ; 320: 126610, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32234655

RESUMO

This paper presents a study of the influence of the harvesting date on concentrations of odorants in Moristel wines of two vintages. The wine made from grapes harvested early facilitated the accumulation of acetaldehyde (associated with low polyphenols concentrations) and higher concentrations of branched acids. A reason for these greater levels could be the lack of reduction factors (NADH or NADPH). Other changes with potential sensory consequences are the decrease of the branched acid/branched alcohol, branched ester/branched acid and branched ester/branched alcohol ratios that occurs as the grapes ripen. Besides, the variations of varietal or typical maturation markers did not have sensory importance. These results suggest that the characteristics of wines associated to the degree of maturity of grapes are mostly related to the changes in the profiles of fermentative compounds (especially acetaldehyde) induced by changes in the polyphenolic content and in the medium in which the yeast develops.


Assuntos
Fermentação , Manipulação de Alimentos , Compostos Orgânicos Voláteis/análise , Vinho/análise , Acetaldeído/análise , Acetaldeído/metabolismo , Álcoois/análise , Álcoois/metabolismo , Ésteres/análise , Ésteres/metabolismo , Odorantes/análise , Saccharomyces cerevisiae/metabolismo , Estações do Ano , Vitis/química , Compostos Orgânicos Voláteis/metabolismo
15.
Plant Mol Biol ; 103(3): 287-302, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32240472

RESUMO

Volatile components in fresh leaves are involved in the regulation of many stress responses, such as insect damage, fungal infection and high temperature. However, the potential function of volatile components in hyperosmotic response is largely unknown. Here, we found that 7-day hyperosmotic treatment specifically led to the accumulation of (Z)-3-hexen-1-ol, (E)-2-hexenal and methyl salicylate. Transcriptome and qRT-PCR analyses suggested the activation of linolenic acid degradation and methyl salicylate processes. Importantly, exogenous (Z)-3-hexen-1-ol pretreatment dramatically enhanced the hyperosmotic stress tolerance of tea plants and decreased stomatal conductance, whereas (E)-2-hexenal and methyl salicylate pretreatments did not exhibit such a function. qRT-PCR analysis revealed that exogenous ABA induced the expressions of related enzyme genes, and (Z)-3-hexen-1-ol could up-regulate the expressions of many DREB and RD genes. Moreover, exogenous (Z)-3-hexen-1-ol tremendously induced the expressions of specific LOX and ADH genes within 24 h. Taken together, hyperosmotic stress induced (Z)-3-hexen-1-ol accumulation in tea plant via the activation of most LOX, HPL and ADH genes, while (Z)-3-hexen-1-ol could dramatically enhance the hyperosmotic stress tolerance via the decrease of stomatal conductance and MDA, accumulation of ABA and proline, activation of DREB and RD gene expressions, and probably positive feedback regulation of LOXs and ADHs. KEY MESSAGE: Hyperosmotic stress induced (Z)-3-hexen-1-ol accumulation in Camellia sinensis via the up-regulation of most LOX, HPL and ADH genes, while (Z)-3-hexen-1-ol could dramatically enhance the hyperosmotic stress tolerance via the decrease of stomatal conductance, accumulation of proline, activation of DREB and RD gene expressions, and probably positive feedback regulation of LOXs and ADHs.


Assuntos
Camellia sinensis/efeitos dos fármacos , Camellia sinensis/metabolismo , Hexanóis/metabolismo , Estresse Fisiológico/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Água , Aldeídos/farmacologia , Tabaco/efeitos dos fármacos , Tabaco/metabolismo
16.
PLoS One ; 15(4): e0231005, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32243466

RESUMO

Silicon (Si) supplementation is well-known for enhancing plant resistance to insect pests, however, only recently studies revealed that Si accumulation in the plant not only confers a mechanical barrier to insect feeding, but also primes jasmonic acid-dependent defenses. Here, we examined whether Si supplementation alters wheat volatile emissions that influence the bird cherry-oat aphid (Rhopalosiphum padi) olfactory preference and the aphid parasitoid Lysiphlebus testaceipes. Even though Si accumulation in wheat did not impact aphid performance, we found that R. padi preferred constitutive volatiles from-Si wheat over those emitted by +Si wheat plants. In Y-tube olfactometer bioassays, the parasitoid was attracted to volatiles from +Si uninfested wheat, but not to those from-Si uninfested wheat. +Si and-Si aphid-infested plants released equally attractive blends to the aphid parasitoid; however, wasps were unable to distinguish +Si uninfested plant odors from those of aphid-infested treatments. GC-MS analyses revealed that +Si uninfested wheat plants emitted increased amounts of a single compound, geranyl acetone, compared to -Si uninfested wheat, but similar to those emitted by aphid-infested treatments. By contrast, Si supplementation in wheat did not alter composition of aphid-induced plant volatiles. Our results show that changes in wheat volatile blend induced by Si accumulation mediate the non-preference behavior of the bird cherry-oat aphid and the attraction of its parasitoid L. testaceipes. Conversely to the literature, Si supplementation by itself seems to work as an elicitor of induced defenses in wheat, and not as a priming agent.


Assuntos
Afídeos , Silício/farmacologia , Triticum/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Vespas , Animais , Afídeos/fisiologia , Controle de Insetos/métodos , Silício/metabolismo , Olfato , Triticum/efeitos dos fármacos , Triticum/metabolismo
17.
Plant Mol Biol ; 103(4-5): 489-505, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32306368

RESUMO

KEY MESSAGE: Cucumber plants adapt their transcriptome and metabolome as result of spider mite infestation with opposite consequences for direct and indirect defences in two genotypes. Plants respond to arthropod attack with the rearrangement of their transcriptome which lead to subsequent phenotypic changes in the plants' metabolome. Here, we analysed transcriptomic and metabolite responses of two cucumber (Cucumis sativus) genotypes to chelicerate spider mites (Tetranychus urticae) during the first 3 days of infestation. Genes associated with the metabolism of jasmonates, phenylpropanoids, terpenoids and L-phenylalanine were most strongly upregulated. Also, genes involved in the biosynthesis of precursors for indirect defence-related terpenoids were upregulated while those involved in the biosynthesis of direct defence-related cucurbitacin C were downregulated. Consistent with the observed transcriptional changes, terpenoid emission increased and cucurbitacin C content decreased during early spider-mite herbivory. To further study the regulatory network that underlies induced defence to spider mites, differentially expressed genes that encode transcription factors (TFs) were analysed. Correlation analysis of the expression of TF genes with metabolism-associated genes resulted in putative identification of regulators of herbivore-induced terpenoid, green-leaf volatiles and cucurbitacin biosynthesis. Our data provide a global image of the transcriptional changes in cucumber leaves in response to spider-mite herbivory and that of metabolites that are potentially involved in the regulation of induced direct and indirect defences against spider-mite herbivory.


Assuntos
Cucumis sativus/imunologia , Cucumis sativus/metabolismo , Metaboloma , Infestações por Ácaros/imunologia , Infestações por Ácaros/metabolismo , Tetranychidae , Transcriptoma , Animais , Vias Biossintéticas/genética , Cucumis sativus/genética , Cucumis sativus/parasitologia , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Genoma de Planta , Genótipo , Herbivoria , Oxilipinas/metabolismo , Fenilalanina/metabolismo , Fenilpropionatos/metabolismo , Doenças das Plantas , Folhas de Planta/metabolismo , Metabolismo Secundário/genética , Terpenos/metabolismo , Fatores de Transcrição/genética , Triterpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
18.
J Chem Ecol ; 46(4): 397-409, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32240482

RESUMO

The oviposition behavior of mosquitoes is mediated by chemical cues. In the malaria mosquito Anopheles gambiae, conspecific larvae produce infochemicals that affect this behavior. Emanations from first instar larvae proved strongly attractive to gravid females, while those from fourth instars caused oviposition deterrence, suggesting that larval developmental stage affected the oviposition choice of the female mosquito.We examined the nature of these chemicals by headspace collection of emanations of water in which larvae of different stages were developing. Four chemicals with putative effects on oviposition behavior were identified: dimethyldisulfide (DMDS) and dimethyltrisulfide (DMTS) were identified in emanations from water containing fourth instars; nonane and 2,4-pentanedione (2,4-PD) were identified in emanations from water containing both first and fourth instars. Dual-choice oviposition studies with these compounds were done in the laboratory and in semi-field experiments in Tanzania.In the laboratory, DMDS and DMTS were associated with oviposition-deterrent effects, while results with nonane and 2,4-PD were inconclusive. In further studies DMDS and DMTS evoked egg retention, while with nonane and 2,4-PD 88% and 100% of female mosquitoes, respectively, laid eggs. In dual-choice semi-field trials DMDS and DMTS caused oviposition deterrence, while nonane and 2,4-PD evoked attraction, inducing females to lay more eggs in bowls containing these compounds compared to the controls. We conclude that oviposition of An. gambiae is mediated by these four infochemicals associated with conspecific larvae, eliciting either attraction or deterrence. High levels of egg retention occurred when females were exposed to chemicals associated with fourth instar larvae.


Assuntos
Anopheles/fisiologia , Quimiotaxia , Percepção Olfatória , Oviposição , Compostos Orgânicos Voláteis/metabolismo , Fatores Etários , Animais , Anopheles/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/metabolismo
19.
J Chem Ecol ; 46(4): 387-396, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32274623

RESUMO

Attractive Toxic Sugar Baits (ATSB) are used in a "lure-and-kill" approach for management of the malaria vector Anopheles gambiae, but the active chemicals were previously unknown. Here we collected volatiles from a mango, Mangifera indica, juice bait which is used in ATSBs in Tanzania and tested mosquito responses. In a Y-tube olfactometer, female mosquitoes were attracted to the mango volatiles collected 24-48 h, 48-72 h and 72-96 h after preparing the bait but volatiles collected at 96-120 h were no longer attractive. Volatile analysis revealed emission of 23 compounds in different chemical classes including alcohols, aldehydes, alkanes, benzenoids, monoterpenes, sesquiterpenes and oxygenated terpenes. Coupled GC-electroantennogram (GC-EAG) recordings from the antennae of An. gambiae showed robust responses to 4 compounds: humulene, (E)-caryophyllene, terpinolene and myrcene. In olfactometer bioassays, mosquitoes were attracted to humulene and terpinolene. (E)-caryophyllene was marginally attractive while myrcene elicited an avoidance response with female mosquitoes. A blend of humulene, (E)-caryophyllene and terpinolene was highly attractive to females (P < 0.001) when tested against a solvent blank. Furthermore, there was no preference when this synthetic blend was offered as a choice against the natural sample. Our study has identified the key compounds from mango juice baits that attract An. gambiae and this information may help to improve the ATSBs currently used against malaria vectors.


Assuntos
Anopheles/fisiologia , Controle de Insetos , Mangifera/química , Feromônios/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Animais , Quimiotaxia , Comportamento Alimentar , Feminino , Cadeia Alimentar
20.
J Chem Ecol ; 46(4): 363-377, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125582

RESUMO

Insects have evolved highly sensitive olfactory sensory systems to detect plant hosts and mates, with plant volatiles playing an important role in informing insect behavior. Chemosensory proteins (CSPs) are thought to play a key role in this process, but in this respect, there is limited information on brown planthopper Nilaparvata lugens, one of the most destructive pests of rice. To expand our understanding of CSP function in N. lugens we explored expression profiles and binding characteristics of NlugCSP3. The ligands with higher binding affinity were also validated by molecular docking and behavioral assays. NlugCSP3 mRNA was expressed at relatively higher levels in antennae and abdomen of 3-day-old unmated macropterous males as well as in antennae of 3-day mated macropterous and brachypterous females. Fluorescence competitive binding assays revealed that 5 out of 25 candidate volatiles are strong binders (Ki < 10 µM). Behavioral assays revealed that nonadecane and 2-tridecanone, which have high binding affinities in fluorescence competition-binding assays, displayed strong attractiveness to N. lugens. Pursuing this further, molecular docking analysis identified key amino acid residues involved in binding volatile compounds. Overall, our data provide a base for further investigation of the potential physiological functions of CSP3 in Nilaparvata lugens, and extend the function of NlugCSP3 in chemoreception of N. lugens.


Assuntos
Expressão Gênica , Hemípteros/genética , Proteínas de Insetos/genética , Compostos Orgânicos Voláteis/metabolismo , Fatores Etários , Aminoácidos/metabolismo , Animais , Antenas de Artrópodes/metabolismo , Feminino , Perfilação da Expressão Gênica , Hemípteros/química , Hemípteros/metabolismo , Proteínas de Insetos/metabolismo , Ligantes , Masculino , Simulação de Acoplamento Molecular , Reprodução , Fatores Sexuais , Asas de Animais/anatomia & histologia
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