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1.
J Chem Ecol ; 45(1): 50-60, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30523520

RESUMO

Cardenolides are classically studied steroidal defenses in chemical ecology and plant-herbivore coevolution. Although milkweed plants (Asclepias spp.) produce up to 200 structurally different cardenolides, all compounds seemingly share the same well-characterized mode of action, inhibition of the ubiquitous Na+/K+ ATPase in animal cells. Over their evolutionary radiation, milkweeds show a quantitative decline of cardenolide production and diversity. This reduction is contrary to coevolutionary predictions and could represent a cost-saving strategy, i.e. production of fewer but more toxic cardenolides. Here we test this hypothesis by tandem cardenolide quantification using HPLC (UV absorption of the unsaturated lactone) and a pharmacological assay (in vitro inhibition of a sensitive Na+/K+ ATPase) in a comparative study of 16 species of Asclepias. We contrast cardenolide concentrations in leaf tissue to the subset of cardenolides present in exuding latex. Results from the two quantification methods were strongly correlated, but the enzymatic assay revealed that milkweed cardenolide mixtures often cause stronger inhibition than equal amounts of a non-milkweed reference cardenolide, ouabain. Cardenolide concentrations in latex and leaves were positively correlated across species, yet latex caused 27% stronger enzyme inhibition than equimolar amounts of leaf cardenolides. Using a novel multiple regression approach, we found three highly potent cardenolides (identified as calactin, calotropin, and voruscharin) to be primarily responsible for the increased pharmacological activity of milkweed cardenolide mixtures. However, contrary to an expected trade-off between concentration and toxicity, later-diverging milkweeds had the lowest amounts of these potent cardenolides, perhaps indicating an evolutionary response to milkweed's diverse community of specialist cardenolide-sequestering insect herbivores.


Assuntos
Asclepias/fisiologia , Borboletas/fisiologia , Cardenolídeos/metabolismo , Herbivoria , Látex/metabolismo , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Animais , Asclepias/química , Asclepias/genética , Borboletas/efeitos dos fármacos , Borboletas/enzimologia , Cardenolídeos/análise , Cardenolídeos/toxicidade , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/toxicidade , Látex/química , Látex/toxicidade , Filogenia , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Suínos
2.
PLoS One ; 13(12): e0209047, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30586439

RESUMO

Coordinated social behaviour is fundamental for ant ecological success. However, even distantly-related organisms, such as plants, have evolved the ability to manipulate ant collective performances to their own advantage. In the parasitic system encompassing Maculinea butterflies, Myrmica ants, and Origanum vulgare plants, the ant-plant interaction elicits the release of a volatile terpenoid compound (carvacrol) which is used by the gravid butterfly to locate the ideal oviposition site. Here we show that this ant-plant association is maintained by the effect of O. vulgare terpenoids on ant behaviour and that food plants might gain protection by Myrmica ants by chemically manipulating workers to forage in their surroundings. The variation in the locomotor ability of three ant species (Formica cinerea, Tetramorium caespitum, and Myrmica scabrinodis) was studied after treatment with the two major O. vulgare terpenoid volatile compounds (i.e., carvacrol and thymol). The brain levels of three biogenic amines (dopamine, tyramine and serotonin) were analysed in ants exposed to the O. vulgare terpenoids by HPLC-ESI-MS/MS. Carvacrol and thymol increased the locomotor activity of all ant species tested, but if blended reduced the movement propensity of Myrmica scabrinodis. Dopamine and tyramine production was positively correlated with the worker locomotor activity. In Myrmica ants, both brain biogenic ammines were negatively correlated with the aggressive behaviour. Blends of O. vulgare volatiles affected the locomotor ability while increased the aggressiveness of Myrmica workers by altering the aminergic regulation in the ant brains. This behavioural manipulation, might enhance partner fidelity and plant protection. Our findings provide new insights supporting a direct role of plant volatiles in driving behavioural changes in social insects through biogenic amine modulation.


Assuntos
Formigas/fisiologia , Comportamento Animal/efeitos dos fármacos , Aminas Biogênicas/metabolismo , Encéfalo/metabolismo , Borboletas/efeitos dos fármacos , Origanum/química , Terpenos/farmacologia , Animais , Formigas/efeitos dos fármacos , Aminas Biogênicas/análise , Encéfalo/efeitos dos fármacos , Borboletas/metabolismo , Cromatografia Líquida de Alta Pressão , Locomoção/efeitos dos fármacos , Origanum/metabolismo , Espectrometria de Massas em Tandem , Terpenos/química , Tiramina/análise
3.
Integr Comp Biol ; 58(5): 1008-1017, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30010963

RESUMO

Heavy metal pollution is a major problem in urban and industrial environments, and has a myriad of negative effects on animals. Quantifying the amount of population-level variation that exists for heavy metal tolerance and how plastic responses to heavy metals play out across generations are essential for understanding how animals respond to pollution. As an initial step toward studying transgenerational effects and population-level variation in concert, we brought cabbage white butterflies (Pieris rapae) from two populations-collected from St. Paul, MN, and Davis, CA-into common conditions and fed them a diet dosed with nickel. To measure transgenerational effects, we reared a second generation in a fully factorial design, within each population, to achieve all combinations of parent and offspring exposure to nickel or control diets. Across both generations, we quantified survival and other fitness-related traits, including development time, body size, and egg size and number. We found both population differences and complex transgenerational effects, including a positive effect of nickel on survival and development time in one of the populations. Overall, nickel exposure was stressful in one population, mainly after two generations of exposure, and had neutral or slightly positive effects on the other. We found no evidence for costs of mismatch between parental and offspring environments. While the reasons for the differences observed between the two populations are unclear, the variation in nickel tolerance observed in this species suggests that some organisms may be less affected by low levels of heavy metal pollution in urban and industrial areas than expected.


Assuntos
Borboletas/fisiologia , Meio Ambiente , Exposição Ambiental , Poluentes Ambientais/efeitos adversos , Aptidão Genética , Níquel/efeitos adversos , Animais , Borboletas/efeitos dos fármacos , Borboletas/genética , California , Cidades , Feminino , Masculino , Minnesota , Distribuição Aleatória , Urbanização
4.
Sci Rep ; 8(1): 5516, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29615771

RESUMO

Certain butterflies utilize plant-acquired alkaloids for their own chemical defense and/or for producing male sex pheromone; a trait known as pharmacophagy. Males of the danaine butterfly, Parantica sita, have been reported to ingest pyrrolizidine alkaloids (PAs) as adults to produce two PA-derived sex pheromone components, viz. danaidone (major) and 7R-hydroxydanaidal. We found, however, that not all PAs that can be precursors for the pheromone serve for mating success of males. Here we show that although the sex pheromone is regarded as a requisite for successful mating, uptake of specific PA(s) (lycopsamine-type PAs) is also imperative for the males to achieve copulation. The increase in the levels of two biogenic amines, octopamine and/or serotonin, in the brain and thoracic ganglia of males fed with specific PA(s) suggested that these alkaloids most likely enhance male mating activity. The results can present new evidence for the evolutionary provenance of pharmacophagous acquisition of PAs in PA-adapted insects.


Assuntos
Borboletas/metabolismo , Copulação , Plantas/metabolismo , Alcaloides de Pirrolizidina/metabolismo , Animais , Transporte Biológico , Borboletas/efeitos dos fármacos , Borboletas/fisiologia , Copulação/efeitos dos fármacos , Masculino , Atrativos Sexuais/biossíntese , Atrativos Sexuais/farmacologia
5.
Am J Bot ; 105(4): 677-686, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29683473

RESUMO

PREMISE OF THE STUDY: Pachypodium (Apocynaceae) is a genus of iconic stem-succulent and poisonous plants endemic to Madagascar and southern Africa. We tested hypotheses about the mode of action and macroevolution of toxicity in this group. We further hypothesized that while monarch butterflies are highly resistant to cardenolide toxins (a type of cardiac glycoside) from American Asclepias, they may be negatively affected by Pachypodium defenses, which evolved independently. METHODS: We grew 16 of 21 known Pachypodium spp. and quantified putative cardenolides by HPLC and also by inhibition of animal Na+ /K+ -ATPase (the physiological target of cardiac glycosides) using an in vitro assay. Pachypodium extracts were tested against monarch caterpillars in a feeding bioassay. We also tested four Asclepias spp. and five Pachypodium spp. extracts, contrasting inhibition of the cardenolide-sensitive porcine Na+ /K+ -ATPase to the monarch's resistant form. KEY RESULTS: We found evidence for low cardenolides by HPLC, but substantial toxicity when extracts were assayed on Na+ /K+ -ATPases. Toxicity showed phylogenetic signal, and taller species showed greater toxicity (this was marginal after phylogenetic correction). Application of Pachypodium extracts to milkweed leaves reduced monarch growth, and this was predicted by inhibition of the sensitive Na+ /K+ -ATPase in phylogenetic analyses. Asclepias extracts were 100-fold less potent against the monarch compared to the porcine Na+ /K+ -ATPase, but this difference was absent for Pachypodium extracts. CONCLUSIONS: Pachypodium contains potent toxicity capable of inhibiting sensitive and cardenolide-adapted Na+ /K+ -ATPases. Given the monarch's sensitivity to Pachypodium, we suggest that these plants contain novel cardiac glycosides or other compounds that facilitate toxicity by binding to Na+ /K+ -ATPases.


Assuntos
Apocynaceae/toxicidade , Cardenolídeos/toxicidade , Animais , Apocynaceae/química , Asclepias/toxicidade , Bioensaio , Borboletas/efeitos dos fármacos , Cardenolídeos/isolamento & purificação , Glicosídeos Cardíacos/toxicidade , Cromatografia Líquida de Alta Pressão , Larva/efeitos dos fármacos , Filogenia , Extratos Vegetais/toxicidade , Folhas de Planta/química , Folhas de Planta/toxicidade , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
6.
Arch Insect Biochem Physiol ; 98(1): e21455, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29532954

RESUMO

The small white butterfly, Pieris rapae (Lepidoptera: Pieridae), is an important pest on Brassicaceae plants, causing heavy crop loss each year. Cytochrome P450 monooxygenase (CYP) is a superfamily of enzymes involved in the detoxification of various xenobiotic compounds, including insecticides. However, little is known about the role of CYP genes in P. rapae. In this study, we identified 63 CYP genes in P. rapae, and analyzed their phylogenetic relationships, exon-intron structures and genomic locations. Moreover, our insecticide-response transcription profiling showed that LD5 doses of lambda-cyhalothrin, chlorantraniliprole, and abamectin significantly increased expression of five (CYP4M59, CYP6AE119, CYP6AE120, CYP6AE121, and CYP6BD18), three (CYP4AU1, CYP6AE120, and CYP6AW1), and five (CYP4L40, CYP4AU1, CYP6AE119, CYP6AW1, and CYP6BD19) CYP genes, respectively; and LD20 doses of the three pesticides significantly upregulated six (CYP4M59, CYP6AE119, CYP6AE120, CYP6AE121, CYP4AU1, and CYP6BD18), six (CYP4G168, CYP4L40, CYP4AU1, CYP6AE120, CYP6AW1, and CYP6BD19), and five (CYP4L40, CYP4AU1, CYP6AB108, CYP6AE119, and CYP6BD19) genes, respectively. When we used LD50 doses of the three insecticides, we reported significantly elevated expression levels of five (CYP4M59, CYP6AE119, CYP6AE120, CYP6BD17, and CYP6BD18), eight (CYP4G168, CYP4L40, CYP4AU1, CYP6AE120, CYP6AE121, CYP6AW1, CYP6BD18, and CYP6BD19), and six (CYP4L40, CYP4S34, CYP6AB108, CYP6AE119, CYP6AE120, and CYP6BD19) genes, respectively. Our expression analysis also revealed that five (CYP4G168, CYP4G169, CYP4S34, CYP6AW1, and CYP6CT3) and three (CYP4L40, CYP6AN33, and CYP6BD17) CYP genes were mainly expressed in the midgut and fat body, respectively, and one CYP gene (CYP6AE119) in the Malpighian tubules. This is the first large-scale report into the characterization of CYP genes in P. rapae.


Assuntos
Borboletas/enzimologia , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Insetos/genética , Inseticidas/farmacologia , Animais , Borboletas/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Expressão Gênica , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Larva/enzimologia , Dose Letal Mediana , Masculino , Filogenia
7.
Bull Entomol Res ; 108(3): 370-379, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29039281

RESUMO

The diamondback moth (Plutella xylostella) and small white cabbage butterfly (Pieris rapae) are the two main serious pests of cruciferous crops (Brassicaceae) that have developed resistance to chemical control methods. In order to avoid such resistance and also the adverse effects of chemical pesticides on the environment, alternative methods have usually been suggested, including the use of plant enzyme inhibitors. Here, the inhibitory effects of proteinaceous inhibitors extracted from wheat, canola, sesame, bean and triticale were evaluated against the digestive α-amylases, larval growth, development and nutritional indecs of the diamondback moth and small white cabbage butterfly. Our results indicated that triticale and wheat extracts inhibited α-amylolytic activity in an alkaline pH, which is in accordance with the moth and butterfly gut α-amylase optimum pH. Dose-dependent inhibition of two crucifer pests by triticale and wheat was observed using spectrophotometry and gel electrophoresis. Implementation of specificity studies showed that wheat and triticale-proteinaceous extract were inactive against Chinese and purple cabbage amylase. Triticale and wheat were resistant against insects' gut proteases. Results of the feeding bioassay indicated that triticale-proteinaceous extract could cause a significant reduction in survival and larval body mass. The results of the nutritional indecs also showed larvae of both species that fed on a Triticale proteinaceous inhibitor-treated diet had the lowest values for the efficiency of conversion of ingested food and relative growth rate. Our observations suggested that triticale shows promise for use in the management of crucifer pests.


Assuntos
Borboletas/efeitos dos fármacos , Produtos Agrícolas/química , Inseticidas/análise , Mariposas/efeitos dos fármacos , Extratos Vegetais/toxicidade , Animais , Brassicaceae , Borboletas/enzimologia , Borboletas/crescimento & desenvolvimento , Mariposas/enzimologia , Mariposas/crescimento & desenvolvimento , Proteínas de Plantas/toxicidade , Triticale/química , alfa-Amilases/antagonistas & inibidores
8.
Pestic Biochem Physiol ; 143: 102-110, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29183577

RESUMO

Insect glutathione S-transferases (GSTs) play essential roles in the detoxification of insecticides and other xenobiotic compounds. The cabbage white butterfly, Pieris rapae, is an economically important agricultural pest. In this study, 17 cDNA sequences encoding putative GSTs were identified in P. rapae. All cDNAs include a complete open reading frame and were designated PrGSTd1-PrGSTz2. Based on phylogenetic analysis, PrGSTs were divided into six classes (delta, epsilon, omega, sigma, theta and zeta). The exon-intron organizations of these PrGSTs were also analysed. Recombinant proteins of eight PrGSTs (PrGSTD1, PrGSTD2, PrGSTE1, PrGSTE2, PrGSTO1, PrGSTS1, PrGSTT1 and PrGSTZ1) were heterologously expressed in Escherichia coli, and all of these proteins displayed glutathione-conjugating activity towards 1-chloro-2,4-dinitrobenzene (CDNB). Expression patterns in various larval tissues, at different life stages, and following exposure to sublethal doses of abamectin, chlorantraniliprole or lambda-cyhalothrin were determined by reverse transcription-quantitative PCR. The results showed that PrGSTe3, PrGSTs1, PrGSTs2, and PrGSTs4 were mainly transcribed in the fat body, while PrGSTe2 was expressed predominantly in the Malpighian tubules. Four genes (PrGSTe2, PrGSTo4, PrGSTs4 and PrGSTt1) were mainly expressed in fourth-instar larvae, while others were ubiquitously expressed in egg, larval, pupa and/or adult stages. Abamectin treatment significantly upregulated ten genes (PrGSTd1, PrGSTd3, PrGSTe1, PrGSTe2, PrGSTo1, PrGSTo3, PrGSTs1, PrGSTs3, PrGSTs4 and PrGSTt1). Chlorantraniliprole and lambda-cyhalothrin treatment significantly upregulated nine genes (PrGSTd1, PrGSTd2, PrGSTe1, PrGSTe2, PrGSTe3, PrGSTs1, PrGSTs3, PrGSTs4 and PrGSTz1) and ten genes (PrGSTd1, PrGSTd3, PrGSTe1, PrGSTe2, PrGSTo1, PrGSTo2, PrGSTs1, PrGSTs2, PrGSTs3 and PrGSTz2), respectively. These GSTs are potentially involved in the detoxification of insecticides.


Assuntos
Borboletas/genética , Glutationa Transferase/genética , Proteínas de Insetos/genética , Animais , Borboletas/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inseticidas/toxicidade , Ivermectina/análogos & derivados , Ivermectina/toxicidade , Masculino , Nitrilos/toxicidade , Filogenia , Piretrinas/toxicidade , ortoaminobenzoatos/toxicidade
9.
Insect Biochem Mol Biol ; 87: 107-116, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28663125

RESUMO

Serotonin (5-hydroxytryptamine, 5-HT) plays a key role in modulating diverse physiological processes and behaviors in both protostomes and deuterostomes. These functions are mediated through the binding of serotonin to its receptors, which are recognized as potential insecticide targets. We investigated the sequence, pharmacology and tissue distribution of three 5-HT receptors (Piera5-HT1A, Piera5-HT1B, Piera5-HT7) from the small white butterfly Pieris rapae, an important pest of cultivated cabbages and other mustard family crops. Activation of Piera5-HT1A or Piera5-HT1B by 5-HT inhibited the production of cAMP in a dose-dependent manner. Stimulation of Piera5-HT7 with 5-HT increased cAMP level significantly. Surprisingly, with the exception of 5-methoxytryptamine, agonists including α-methylserotonin, 8-Hydroxy-DPAT and 5-carboxamidotryptamine activated these receptors poorly. The results are consistent with previous findings in Manduca sexta. All three receptors were blocked by methiothepin, but ketanserin and yohimbine were not effective. The selective mammalian 5-HT receptor antagonists SB 216641 and SB 269970 displayed potent inhibition effects on Piera5-HT1B and Piera5-HT7 respectively. The results we achieved here indicate that the pharmacological properties of Lepidoptera 5-HT receptors are quite different from those in other insects and vertebrates and may contribute to development of new selective pesticides. This study offers important information on three 5-HT receptors from P. rapae that will facilitate further analysis of the functions of 5-HT receptors in insects.


Assuntos
Borboletas/metabolismo , Proteínas de Insetos/fisiologia , Receptores de Serotonina/fisiologia , Animais , Borboletas/efeitos dos fármacos , AMP Cíclico/biossíntese , Especificidade de Órgãos , Serotonina/farmacologia , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
10.
Pest Manag Sci ; 73(11): 2259-2266, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28466580

RESUMO

BACKGROUND: Investigating the impact of pesticides on non-target organisms is essential for sustainable integrated pest management programs. We therefore assessed the toxicity of ten insecticides to the brassica caterpillar Ascia monuste and its ant predator Solenopsis saevissima and examined the effect that the insecticide synergists had on toxicity to the predator. We also assessed the residual period of control and impact of the insecticides during the brassica growing cycle. RESULTS: All insecticides except flubendiamide exhibited mortality above the threshold required by Brazilian legislation (80%). Chlorantraniliprole, cyantraniliprole, indoxacarb and spinosad exhibited lower toxicity to the ant predator than they did to the brassica caterpillar. The results obtained for synergized insecticides suggest that selectivity to the predator was due the involvement of cytochrome P450-dependent monooxygenases. Chlorfenapyr and cyantraniliprole exhibited the highest residual periods of control to the brassica caterpillar, whereas malathion had the greatest impact on the predator. CONCLUSION: Most of the insecticides efficiently controlled the brassica caterpillar, but not all exhibited selectivity to the predator. Therefore, due to the distinctive responses of organisms with respect to residual periods of control and the impact of the insecticides, spraying frequency must be strongly considered in integrated pest management programs. © 2017 Society of Chemical Industry.


Assuntos
Formigas/efeitos dos fármacos , Borboletas/efeitos dos fármacos , Inseticidas/farmacologia , Inseticidas/toxicidade , Animais , Brassica/crescimento & desenvolvimento , Brasil , Borboletas/crescimento & desenvolvimento , Cadeia Alimentar , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Controle de Pragas
11.
J Agric Food Chem ; 65(22): 4456-4463, 2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28494582

RESUMO

Six new highly oxygenated grayanane diterpenoids, neopierisoids G-L, 1-6, together with 10 known related compounds, 7-16, were identified from the flowers of the poisonous plant Pieris japonica. The structures were elucidated on the basis of comprehensive NMR spectroscopy and mass analysis. The relative configurations of 1-6 were elucidated by analysis of ROESY spectra and comparison of NMR data with the analogues. The absolute configurations of 1-6 were established by the X-ray diffraction analysis of 1 and comparison of the CD spectra of 1-6. Compared with the skeleton of the normal grayanane diterpenoids, compounds 1-6 shared an unusual seco A ring moiety. The antifeedant activities of compounds 1-16 against Pieris brassicae were evaluated by using a dual-choice bioassay, and compounds 1-10 with a normal grayanane skeleton showed potent antifeedant activity against P. brassicae. The structure-activity relationships of antifeedant activities of 1-16 against P. brassicae are discussed.


Assuntos
Borboletas/efeitos dos fármacos , Diterpenos/química , Diterpenos/farmacologia , Ericaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Borboletas/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Flores/química , Estrutura Molecular , Relação Estrutura-Atividade
12.
Insect Biochem Mol Biol ; 85: 21-31, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28455184

RESUMO

Phytophagous insects have to deal with toxic defense compounds from their host plants. Although it is known that insects have evolved genes and mechanisms to detoxify plant allochemicals, how specialist and generalist precisely respond to specific secondary metabolites at the molecular level is less understood. Here we studied the larval performance and transcriptome of the generalist moth Heliothis virescens and the specialist butterfly Pieris brassicae feeding on Arabidopsis thaliana genotypes with different glucosinolate (GS) levels. H. virescens larvae gained significantly more weight on the GS-deficient mutant quadGS compared to wild-type (Col-0) plants. On the contrary, P. brassicae was unaffected by the presence of GS and performed equally well on both genotypes. Strikingly, there was a considerable differential gene expression in H. virescens larvae feeding on Col-0 compared to quadGS. In contrast, compared to H. virescens, P. brassicae displayed a much-reduced transcriptional activation when fed on both plant genotypes. Transcripts coding for putative detoxification enzymes were significantly upregulated in H. virescens, along with digestive enzymes and transposable elements. These data provide an unprecedented view on transcriptional changes that are specifically activated by GS and illustrate differential molecular responses that are linked to adaptation to diet in lepidopteran herbivores.


Assuntos
Borboletas/efeitos dos fármacos , Glucosinolatos/farmacologia , Herbivoria , Mariposas/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Animais , Arabidopsis , Borboletas/genética , Borboletas/metabolismo , Regulação para Baixo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Inativação Metabólica/genética , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Mariposas/genética , Mariposas/metabolismo , Análise de Sequência de RNA
13.
J Chem Ecol ; 42(11): 1122-1129, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27714574

RESUMO

The common grass yellow butterfly, Eurema mandarina (formerly Eurema hecabe mandarina) (Lepidoptera, Pieridae), recently has been separated taxonomically from a subtropical population of Eurema hecabe in Japan. This species is widely distributed in the temperate region of Japan, and feeds mainly on various ligneous plants within the Fabaceae. We attempted to identify an oviposition stimulant for E. mandarina from its primary hosts, Albizia julibrissin and Lespedeza cuneata. In both hosts, crude extract and an aqueous fraction elicited oviposition responses from gravid females. A polar subfraction of the aqueous fraction also stimulated high oviposition-stimulatory activity, comparable to the original aqueous fraction, suggesting that E. mandarina females use water-soluble compounds for host recognition. Subsequent activity-directed fractionation by ion exchange chromatography indicated that one of the key substances was contained in the neutral/amphoteric fraction. Chemical analyses revealed that the active fractions of both hosts contained D-(+)-pinitol as the major component. We examined female responses to authentic D-pinitol and found that it induced oviposition responses at concentrations greater than 0.1 %. Since this cyclitol is omnipresent in Fabaceae, we conclude that D-pinitol plays a role in mediating oviposition of E. mandarina on fabaceous plants.


Assuntos
Borboletas/efeitos dos fármacos , Borboletas/fisiologia , Fabaceae/química , Inositol/análogos & derivados , Oviposição/efeitos dos fármacos , Animais , Feminino , Inositol/química , Inositol/isolamento & purificação , Inositol/farmacologia
14.
J Chem Ecol ; 42(5): 368-81, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27167383

RESUMO

Plants damaged by herbivores emit volatile organic compounds (VOCs) that are used by parasitoids for host location. In nature, however, plants are exposed to multiple abiotic and biotic stresses of varying intensities, which may affect tritrophic interactions. Here, we studied the effects of ozone exposure and feeding by Pieris brassicae larvae on the VOCs emitted by Brassica nigra and the effects on oriented flight of the parasitoid Cotesia glomerata. We also investigated the oriented flight of C. glomerata in a wind-tunnel with elevated ozone levels. Herbivore-feeding induced the emission of several VOCs, while ozone alone had no significant effect. However, exposure to 120 ppb ozone, followed by 24 hr of herbivore-feeding, induced higher emissions of all VOCs as compared to herbivore-feeding alone. In accordance, herbivore-damaged plants elicited more oriented flights than undamaged plants, whereas plants exposed to 120 ppb ozone and 24 hr of herbivore-feeding elicited more oriented flights than plants subjected to herbivore-feeding alone. Ozone enrichment of the wind-tunnel air appeared to negatively affect orientation of parasitoids at 70 ppb, but not at 120 ppb. These results suggest that the combination of ozone and P. brassicae-feeding modulates VOC emissions, which significantly influence foraging efficiency of C. glomerata.


Assuntos
Cadeia Alimentar , Herbivoria/efeitos dos fármacos , Mostardeira/efeitos dos fármacos , Mostardeira/metabolismo , Ozônio/farmacologia , Animais , Borboletas/efeitos dos fármacos , Borboletas/fisiologia , Ingestão de Alimentos/efeitos dos fármacos , Voo Animal/efeitos dos fármacos , Interações Hospedeiro-Parasita/efeitos dos fármacos , Himenópteros/efeitos dos fármacos , Himenópteros/fisiologia , Mostardeira/parasitologia , Mostardeira/fisiologia , Orientação/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
15.
J Exp Biol ; 219(Pt 10): 1488-94, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26944488

RESUMO

Flying insects have the highest known mass-specific demand for oxygen, which makes it likely that reduced availability of oxygen might limit sustained flight, either instead of or in addition to the limitation due to metabolite resources. The Glanville fritillary butterfly (Melitaea cinxia) occurs as a large metapopulation in which adult butterflies frequently disperse between small local populations. Here, we examine how the interaction between oxygen availability and fuel use affects flight performance in the Glanville fritillary. Individuals were flown under either normoxic (21 kPa O2) or hypoxic (10 kPa O2) conditions and their flight metabolism was measured. To determine resource use, levels of circulating glucose, trehalose and whole-body triglyceride were recorded after flight. Flight performance was significantly reduced in hypoxic conditions. When flown under normoxic conditions, we observed a positive correlation among individuals between post-flight circulating trehalose levels and flight metabolic rate, suggesting that low levels of circulating trehalose constrains flight metabolism. To test this hypothesis experimentally, we measured the flight metabolic rate of individuals injected with a trehalase inhibitor. In support of the hypothesis, experimental butterflies showed significantly reduced flight metabolic rate, but not resting metabolic rate, in comparison to control individuals. By contrast, under hypoxia there was no relationship between trehalose and flight metabolic rate. Additionally, in this case, flight metabolic rate was reduced in spite of circulating trehalose levels that were high enough to support high flight metabolic rate under normoxic conditions. These results demonstrate a significant interaction between oxygen and energy availability for the control of flight performance.


Assuntos
Borboletas/fisiologia , Metabolismo Energético , Voo Animal/fisiologia , Fritillaria/parasitologia , Oxigênio/metabolismo , Animais , Metabolismo Basal/efeitos dos fármacos , Metabolismo Basal/fisiologia , Borboletas/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Feminino , Voo Animal/efeitos dos fármacos , Glucose/análise , Hipóxia/metabolismo , Masculino , Análise de Regressão , Descanso , Inanição/metabolismo , Trealase/antagonistas & inibidores , Trealase/metabolismo , Trealose/análise
16.
PLoS One ; 11(3): e0152264, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27011315

RESUMO

Nutritional enhancement of crops using genetic engineering can potentially affect herbivorous pests. Recently, oilseed crops have been genetically engineered to produce the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at levels similar to that found in fish oil; to provide a more sustainable source of these compounds than is currently available from wild fish capture. We examined some of the growth and development impacts of adding EPA and DHA to an artificial diet of Pieris rapae, a common pest of Brassicaceae plants. We replaced 1% canola oil with EPA: DHA (11:7 ratio) in larval diets, and examined morphological traits and growth of larvae and ensuing adults across 5 dietary treatments. Diets containing increasing amounts of EPA and DHA did not affect developmental phenology, larval or pupal weight, food consumption, nor larval mortality. However, the addition of EPA and DHA in larval diets resulted in progressively heavier adults (F 4, 108 = 6.78; p = 0.011), with smaller wings (p < 0.05) and a higher frequency of wing deformities (R = 0.988; p = 0.001). We conclude that the presence of EPA and DHA in diets of larval P. rapae may alter adult mass and wing morphology; therefore, further research on the environmental impacts of EPA and DHA production on terrestrial biota is advisable.


Assuntos
Brassicaceae/metabolismo , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Graxos Ômega-3/farmacologia , Animais , Brassicaceae/genética , Brassicaceae/parasitologia , Borboletas/efeitos dos fármacos , Borboletas/crescimento & desenvolvimento , Dieta , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos Ômega-3/metabolismo , Engenharia Genética , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Asas de Animais/efeitos dos fármacos
17.
Toxins (Basel) ; 8(2): 52, 2016 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-26907346

RESUMO

Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Here, we report that Pteromalus puparum venom impairs the antimicrobial activity of its host Pieris rapae. Inhibition zone results showed that bead injection induced the antimicrobial activity of the host hemolymph but that venom inhibited it. The cDNAs encoding cecropin and lysozyme were screened. Relative quantitative PCR results indicated that all of the microorganisms and bead injections up-regulated the transcript levels of the two genes but that venom down-regulated them. At 8 h post bead challenge, there was a peak in the transcript level of the cecropin gene, whereas the peak of lysozyme gene occurred at 24 h. The transcripts levels of the two genes were higher in the granulocytes and fat body than in other tissues. RNA interference decreased the transcript levels of the two genes and the antimicrobial activity of the pupal hemolymph. Venom injections similarly silenced the expression of the two genes during the first 8 h post-treatment in time- and dose-dependent manners, after which the silence effects abated. Additionally, recombinant cecropin and lysozyme had no significant effect on the emergence rate of pupae that were parasitized by P. puparum females. These findings suggest one mechanism of impairing host antimicrobial activity by parasitoid venom.


Assuntos
Borboletas/efeitos dos fármacos , Borboletas/parasitologia , Regulação da Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Parasita , Venenos de Vespas/toxicidade , Vespas/fisiologia , Animais , Borboletas/genética , Borboletas/imunologia , Hemolinfa/imunologia , Imunidade Humoral/efeitos dos fármacos , Proteínas de Insetos/genética , Muramidase/genética , Pupa/efeitos dos fármacos , Pupa/genética , Pupa/imunologia , Pupa/parasitologia
18.
Proc Biol Sci ; 282(1818): 20151865, 2015 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-26538594

RESUMO

Insect resistance to plant toxins is widely assumed to have evolved in response to using defended plants as a dietary resource. We tested this hypothesis in the milkweed butterflies (Danaini) which have progressively evolved higher levels of resistance to cardenolide toxins based on amino acid substitutions of their cellular sodium-potassium pump (Na(+)/K(+)-ATPase). Using chemical, physiological and caterpillar growth assays on diverse milkweeds (Asclepias spp.) and isolated cardenolides, we show that resistant Na(+)/K(+)-ATPases are not necessary to cope with dietary cardenolides. By contrast, sequestration of cardenolides in the body (as a defence against predators) is associated with the three levels of Na(+)/K(+)-ATPase resistance. To estimate the potential physiological burden of cardenolide sequestration without Na(+)/K(+)-ATPase adaptations, we applied haemolymph of sequestering species on isolated Na(+)/K(+)-ATPase of sequestering and non-sequestering species. Haemolymph cardenolides dramatically impair non-adapted Na(+)/K(+)-ATPase, but had systematically reduced effects on Na(+)/K(+)-ATPase of sequestering species. Our data indicate that major adaptations to plant toxins may be evolutionarily linked to sequestration, and may not necessarily be a means to eat toxic plants. Na(+)/K(+)-ATPase adaptations thus were a potential mechanism through which predators spurred the coevolutionary arms race between plants and insects.


Assuntos
Asclepias/química , Borboletas/efeitos dos fármacos , Cardenolídeos/metabolismo , Adaptação Biológica , Animais , Asclepias/parasitologia , Evolução Biológica , Borboletas/crescimento & desenvolvimento , Borboletas/metabolismo , Dieta , Hemolinfa/química , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , ATPase Trocadora de Sódio-Potássio/metabolismo , Especificidade da Espécie
19.
J Chem Ecol ; 41(10): 948-55, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26399433

RESUMO

As it pertains to insect herbivores, the preference-performance hypothesis posits that females will choose oviposition sites that maximize their offspring's fitness. However, both genetic and environmental cues contribute to oviposition preference, and occasionally "oviposition mistakes" occur, where insects oviposit on hosts unsuitable for larval development. Pieris virginiensis is a pierine butterfly native to North America that regularly oviposits on an invasive plant, Alliaria petiolata, but the caterpillars are unable to survive. Alliaria petiolata has high concentrations of the glucosinolate sinigrin in its tissues, as well as a hydroxynitrile glucoside, alliarinoside. We investigated sinigrin as a possible cause of mistake oviposition, and sinigrin and alliarinoside as possible causes of larval mortality. We found that sinigrin applied to leaves of Cardamine diphylla, a major host of P. virginiensis that does not produce sinigrin, had no effect on oviposition rates. We tested the effect of sinigrin on larval performance using two host plants, one lacking sinigrin (C. diphylla) and one with sinigrin naturally present (Brassica juncea). We found no effect of sinigrin application on survival of caterpillars fed C. diphylla, but sinigrin delayed pupation and decreased pupal weight. On B. juncea, sinigrin decreased survival, consumption, and caterpillar growth. We also tested the response of P. virginiensis caterpillars to alliarinoside, a compound unique to A. petiolata, which was applied to B. oleracea. We found a significant reduction in survival, leaf consumption, and caterpillar size when alliarinoside was consumed. The 'novel weapon' alliarinoside likely is largely responsible for larval failure on the novel host A. petiolata. Sinigrin most likely contributes to the larval mortality observed, however, we did not observe any effect of sinigrin on oviposition by P. virginiensis females. Further research needs to be done on non-glucosinolate contact cues, and volatile signals that may induce P. virginiensis oviposition.


Assuntos
Brassicaceae/química , Borboletas/efeitos dos fármacos , Cadeia Alimentar , Glucosídeos/farmacologia , Glucosinolatos/farmacologia , Nitrilos/farmacologia , Oviposição/efeitos dos fármacos , Animais , Borboletas/crescimento & desenvolvimento , Borboletas/fisiologia , Cardamine/química , Feminino , Espécies Introduzidas , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Longevidade/efeitos dos fármacos , Mostardeira/química , New York , Folhas de Planta/química
20.
Naturwissenschaften ; 102(3-4): 19, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25839080

RESUMO

Monarch butterflies (Danaus plexippus) frequently consume milkweed in and near agroecosystems and consequently may be exposed to pesticides like neonicotinoids. We conducted a dose response study to determine lethal and sublethal doses of clothianidin using a 36-h exposure scenario. We then quantified clothianidin levels found in milkweed leaves adjacent to maize fields. Toxicity assays revealed LC10, LC50, and LC90 values of 7.72, 15.63, and 30.70 ppb, respectively. Sublethal effects (larval size) were observed at 1 ppb. Contaminated milkweed plants had an average of 1.14±0.10 ppb clothianidin, with a maximum of 4 ppb in a single plant. This research suggests that clothianidin could function as a stressor to monarch populations.


Assuntos
Borboletas/efeitos dos fármacos , Guanidinas/toxicidade , Tiazóis/toxicidade , Animais , Poluentes Ambientais/toxicidade , Larva/efeitos dos fármacos , Dose Letal Mediana , Neonicotinoides
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