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May R Berenbaum - One of the best experts on this subject based on the ideXlab platform.
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aliphatic esters as targets of esterase activity in the parsnip Webworm depressaria pastinacella
Journal of Chemical Ecology, 2012Co-Authors: Arthur R Zangerl, Ling Hsiu Liao, Tania Jogesh, May R BerenbaumAbstract:As a specialist on the reproductive structures of Pastinaca sativa and species in the related genus Heracleum, the parsnip Webworm (Depressaria pastinacella) routinely encounters a distinctive suite of phytochemicals in hostplant tissues. Little is known, however, about the detoxification mechanisms upon which this species relies to metabolize these compounds. In this study, larval guts containing hostplant tissues were homogenized, and metabolism was determined by incubating reactions with and without NADPH and analyzing for substrate disappearance and product appearance by gas chromatography–mass spectrometry. Using this approach, we found indications of carboxylesterase activity, in the form of appropriate alcohol metabolites for three aliphatic esters in hostplant tissues—octyl acetate, octyl butyrate, and hexyl butyrate. Involvement of Webworm esterases in hostplant detoxification subsequently was confirmed with metabolism assays with pure compounds. This study is the first to implicate esterases in lepidopteran larval midgut metabolism of aliphatic esters, ubiquitous constituents of flowers and fruits. In addition, this method confirmed that Webworms detoxify furanocoumarins and myristicin in their hostplants via cytochrome P450-mediated metabolism, and demonstrated that these enzymes also metabolize the coumarin osthol and the fatty acid derivative palmitolactone.
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Tritrophic Effects of Xanthotoxin on the Polyembryonic Parasitoid Copidosoma sosares (Hymenoptera: Encyrtidae)
Journal of Chemical Ecology, 2008Co-Authors: Evan C. Lampert, Arthur R Zangerl, May R BerenbaumAbstract:Plant chemistry can have deleterious effects on insect parasitoids, which include the reduction in body size, increased development time, and increased mortality. We examined the effects of xanthotoxin, a linear furanocoumarin, on the polyembryonic encyrtid wasp Copidosoma sosares , a specialist parasitoid that attacks the parsnip Webworm, Depressaria pastinacella , itself a specialist on furanocoumarin-producing plants. Furanocoumarins, allelochemicals abundant in the Apiaceae and Rutaceae, are toxic to a wide range of herbivores. In this study, we reared parasitized Webworms on artificial diets containing no xanthotoxin (control) or low or high concentrations of xanthotoxin. Clutch sizes of both male and female C. sosares broods were more than 20% smaller when they developed in hosts fed the diet containing high concentrations of xanthotoxin. Xanthotoxin concentration in the artificial diet had no effect on the development time of C. sosares , nor did it have an effect on the body size (length of hind tibia) of individual adult male and female C. sosares in single-sex broods. Webworms fed artificial diets containing low or high concentrations of xanthotoxin were not significantly smaller, and their development time was similar to that of Webworms fed a xanthotoxin-free diet. Mortality of Webworms was not affected by xanthotoxin in their artificial diet. Therefore, dietary xanthotoxin did not appear to affect C. sosares via impairment of host health. However, unmetabolized xanthotoxin was found in D. pastinacella hemolymph where C. sosares embryos develop. Hemolymph concentrations were fourfold greater in Webworms fed the high-xanthotoxin-containing diet than in Webworms fed the low-xanthotoxin-containing diet. We failed to detect any xanthotoxin metabolism by either C. sosares embryos or precocious larvae. Therefore, the observed tritrophic effects of xanthotoxin are likely to be due to the effects of xanthotoxin after direct contact in the hemolymph rather than to the effects of compromised host quality.
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Parsnip Webworms and host plants at home and abroad: trophic complexity in a geographic mosaic.
Ecology, 2006Co-Authors: May R Berenbaum, Arthur R ZangerlAbstract:Due to differences in the structure of communities in which interactions are embedded, the intensity of interactions between species may vary with location; thus, what results from differences in outcomes and in degree of specialization is a geographic mosaic, which provides the raw material for divergent coevolutionary trajectories. Where selection intensity is great, reciprocal responses are likely in so-called "hotspots"; in contrast, where selection pressures are relaxed, reciprocal responses in "coldspots" are far less likely to occur. There are few if any studies examining how a gradient of increasing trophic complexity might influence the probability of phenotype matching and, correspondingly, the "temperature" of the coevolutionary interaction. This study was conducted to compare outcomes of the interaction between wild parsnip (Pastinaca sativa) and parsnip Webworm (Depressaria pastinacella) in its indigenous area, Europe, to its area of introduction, the midwestern United States. Specifically, we tested the hypothesis that increasing trophic complexity, represented by alternate host plants or the presence of natural enemies, reduces the selective impact of parsnip Webworms and hence diminishes linkage between host plant chemistry and Webworms that would be expected in coevolutionary hotspots. This comparison of a two-species interaction in its area of introduction and its area of indigeneity revealed common patterns that are more reflective of interaction temperature than of continental origin. Where Webworms are rare, parsnips produce lower levels of xanthotoxin and bergapten in both the midwestern United States and Netherlands populations. However, the most striking result from this intercontinental comparison is that what is a ubiquitous two-species interaction in North America is in fact exceptional in Europe; Webworms could more reliably be found infesting H. sphondylium even where P. sativa was available as well. This preference for H. sphondylium exists despite the comparatively high probability of parasitism associated with this host plant and may reflect the overall lower furanocoumarin content of H. sphondylium. The interaction of parsnip Webworms and wild parsnips at home and away demonstrates clearly the potential for rapid contemporary evolution of chemical traits upon re-association with a coevolved enemy, a potential evolutionary outcome that should be considered in the design and implementation of future weed biological control programs.
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Furanocoumarins and their detoxification in a tri-trophic interaction
CHEMOECOLOGY, 2006Co-Authors: Jennifer L. Mcgovern, Arthur R Zangerl, May R BerenbaumAbstract:The parsnip Webworm, Depressaria pastinacella , specializes on wild parsnip, Pastinaca sativa , and several species of Heracleum , hostplants rich in toxic furanocoumarins. Rates of furanocoumarin metabolism in this species are among the highest known for any insect. Within its native range in Europe, Webworms are heavily parasitized by the polyembryonic parasitoid wasp Copidosoma sosares . In this study, we determined whether these parasitoids are exposed to furanocoumarins in host hemolymph, whether they can metabolize furanocoumarins, and whether parasitism influences the ability of Webworms to detoxify furanocoumarins. Hemolymph of Webworms fed artificial diet containing 0.3 % fresh weight xanthotoxin, a furanocoumarin prevalent in wild parsnip hosts, contained trace amounts of this toxin; as well, hemolymph of Webworms consuming P. sativa flowers and fruits contained trace amounts of six of seven furanocoumarins present in the hostplant. Thus, parasitoids likely encounter furanocoumarins in host hemolymph. Assays of xanthotoxin metabolism in C. sosares failed to show any ability to metabolize this compound. Parasitized Webworms, collected from populations of Heracleum sphondylium in the Netherlands in 2004, were on average 55 % larger by weight than unparasitized individuals. This weight is inclusive of host and parasitoid masses. Absolute rates of detoxification (nmoles min^−1) of five different furanocoumarins were indistinguishable between parasitized and unparasitized ultimate instars, suggesting that the intrinsic rates of metabolism are fixed. Thus, although parasitized larvae are larger, detoxification rates are not commensurate with size; rates in parasitized larvae expressed per gram of larval mass were 25 % lower than in unparasitized larvae.
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Lutein Sequestration and Furanocoumarin Metabolism in Parsnip Webworms Under Different Ultraviolet Light Regimes in the Montane West
Journal of Chemical Ecology, 2006Co-Authors: Mark J. Carroll, May R BerenbaumAbstract:Both biotic and abiotic selection pressures can contribute to geographic variation in allelochemical production in plants. We examined furanocoumarin production in western North American populations of Heracleum lanatum and Pastinaca sativa that, at different latitudes and altitudes, experience different ultraviolet (UV) light regimes. Total furanocoumarins and linear furanocoumarins of fruits were negatively correlated with UV irradiance, whereas amounts of angular furanocoumarins, which are generally less phototoxic, were not. Another factor potentially influencing furanocoumarin production is the presence of the parsnip Webworm Depressaria pastinacella , (Lepidoptera: Oecophoridae), an herbivore that feeds on reproductive structures of both plant species. These insects sequester lutein from their host plants; this carotenoid acts to ameliorate furanocoumarin toxicity. Although the concentration of lutein in fruits did not vary with UV irradiance, lutein sequestration by sixth instars was positively correlated with UV irradiance. Webworm populations are variably infested with the polyembryonic Webworm parasitoid Copidosoma sosares Walker (Hymenoptera: Encyrtidae). H. lanatum fruits from populations with Webworms parasitized by C. sosares had lower concentrations of furanocoumarins, with the exception of sphondin, than fruits from plants infested with Webworms free from parasitism. Lower levels of these furanocoumarins may reduce negative effects on the fitness of this parasitoid. In contrast with the variation in furanocoumarin content, the ability of Webworms to metabolize furanocoumarins by cytochrome P450 did not differ significantly among populations from New Mexico to Alberta.
Arthur R Zangerl - One of the best experts on this subject based on the ideXlab platform.
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aliphatic esters as targets of esterase activity in the parsnip Webworm depressaria pastinacella
Journal of Chemical Ecology, 2012Co-Authors: Arthur R Zangerl, Ling Hsiu Liao, Tania Jogesh, May R BerenbaumAbstract:As a specialist on the reproductive structures of Pastinaca sativa and species in the related genus Heracleum, the parsnip Webworm (Depressaria pastinacella) routinely encounters a distinctive suite of phytochemicals in hostplant tissues. Little is known, however, about the detoxification mechanisms upon which this species relies to metabolize these compounds. In this study, larval guts containing hostplant tissues were homogenized, and metabolism was determined by incubating reactions with and without NADPH and analyzing for substrate disappearance and product appearance by gas chromatography–mass spectrometry. Using this approach, we found indications of carboxylesterase activity, in the form of appropriate alcohol metabolites for three aliphatic esters in hostplant tissues—octyl acetate, octyl butyrate, and hexyl butyrate. Involvement of Webworm esterases in hostplant detoxification subsequently was confirmed with metabolism assays with pure compounds. This study is the first to implicate esterases in lepidopteran larval midgut metabolism of aliphatic esters, ubiquitous constituents of flowers and fruits. In addition, this method confirmed that Webworms detoxify furanocoumarins and myristicin in their hostplants via cytochrome P450-mediated metabolism, and demonstrated that these enzymes also metabolize the coumarin osthol and the fatty acid derivative palmitolactone.
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Tritrophic Effects of Xanthotoxin on the Polyembryonic Parasitoid Copidosoma sosares (Hymenoptera: Encyrtidae)
Journal of Chemical Ecology, 2008Co-Authors: Evan C. Lampert, Arthur R Zangerl, May R BerenbaumAbstract:Plant chemistry can have deleterious effects on insect parasitoids, which include the reduction in body size, increased development time, and increased mortality. We examined the effects of xanthotoxin, a linear furanocoumarin, on the polyembryonic encyrtid wasp Copidosoma sosares , a specialist parasitoid that attacks the parsnip Webworm, Depressaria pastinacella , itself a specialist on furanocoumarin-producing plants. Furanocoumarins, allelochemicals abundant in the Apiaceae and Rutaceae, are toxic to a wide range of herbivores. In this study, we reared parasitized Webworms on artificial diets containing no xanthotoxin (control) or low or high concentrations of xanthotoxin. Clutch sizes of both male and female C. sosares broods were more than 20% smaller when they developed in hosts fed the diet containing high concentrations of xanthotoxin. Xanthotoxin concentration in the artificial diet had no effect on the development time of C. sosares , nor did it have an effect on the body size (length of hind tibia) of individual adult male and female C. sosares in single-sex broods. Webworms fed artificial diets containing low or high concentrations of xanthotoxin were not significantly smaller, and their development time was similar to that of Webworms fed a xanthotoxin-free diet. Mortality of Webworms was not affected by xanthotoxin in their artificial diet. Therefore, dietary xanthotoxin did not appear to affect C. sosares via impairment of host health. However, unmetabolized xanthotoxin was found in D. pastinacella hemolymph where C. sosares embryos develop. Hemolymph concentrations were fourfold greater in Webworms fed the high-xanthotoxin-containing diet than in Webworms fed the low-xanthotoxin-containing diet. We failed to detect any xanthotoxin metabolism by either C. sosares embryos or precocious larvae. Therefore, the observed tritrophic effects of xanthotoxin are likely to be due to the effects of xanthotoxin after direct contact in the hemolymph rather than to the effects of compromised host quality.
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Parsnip Webworms and host plants at home and abroad: trophic complexity in a geographic mosaic.
Ecology, 2006Co-Authors: May R Berenbaum, Arthur R ZangerlAbstract:Due to differences in the structure of communities in which interactions are embedded, the intensity of interactions between species may vary with location; thus, what results from differences in outcomes and in degree of specialization is a geographic mosaic, which provides the raw material for divergent coevolutionary trajectories. Where selection intensity is great, reciprocal responses are likely in so-called "hotspots"; in contrast, where selection pressures are relaxed, reciprocal responses in "coldspots" are far less likely to occur. There are few if any studies examining how a gradient of increasing trophic complexity might influence the probability of phenotype matching and, correspondingly, the "temperature" of the coevolutionary interaction. This study was conducted to compare outcomes of the interaction between wild parsnip (Pastinaca sativa) and parsnip Webworm (Depressaria pastinacella) in its indigenous area, Europe, to its area of introduction, the midwestern United States. Specifically, we tested the hypothesis that increasing trophic complexity, represented by alternate host plants or the presence of natural enemies, reduces the selective impact of parsnip Webworms and hence diminishes linkage between host plant chemistry and Webworms that would be expected in coevolutionary hotspots. This comparison of a two-species interaction in its area of introduction and its area of indigeneity revealed common patterns that are more reflective of interaction temperature than of continental origin. Where Webworms are rare, parsnips produce lower levels of xanthotoxin and bergapten in both the midwestern United States and Netherlands populations. However, the most striking result from this intercontinental comparison is that what is a ubiquitous two-species interaction in North America is in fact exceptional in Europe; Webworms could more reliably be found infesting H. sphondylium even where P. sativa was available as well. This preference for H. sphondylium exists despite the comparatively high probability of parasitism associated with this host plant and may reflect the overall lower furanocoumarin content of H. sphondylium. The interaction of parsnip Webworms and wild parsnips at home and away demonstrates clearly the potential for rapid contemporary evolution of chemical traits upon re-association with a coevolved enemy, a potential evolutionary outcome that should be considered in the design and implementation of future weed biological control programs.
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Furanocoumarins and their detoxification in a tri-trophic interaction
CHEMOECOLOGY, 2006Co-Authors: Jennifer L. Mcgovern, Arthur R Zangerl, May R BerenbaumAbstract:The parsnip Webworm, Depressaria pastinacella , specializes on wild parsnip, Pastinaca sativa , and several species of Heracleum , hostplants rich in toxic furanocoumarins. Rates of furanocoumarin metabolism in this species are among the highest known for any insect. Within its native range in Europe, Webworms are heavily parasitized by the polyembryonic parasitoid wasp Copidosoma sosares . In this study, we determined whether these parasitoids are exposed to furanocoumarins in host hemolymph, whether they can metabolize furanocoumarins, and whether parasitism influences the ability of Webworms to detoxify furanocoumarins. Hemolymph of Webworms fed artificial diet containing 0.3 % fresh weight xanthotoxin, a furanocoumarin prevalent in wild parsnip hosts, contained trace amounts of this toxin; as well, hemolymph of Webworms consuming P. sativa flowers and fruits contained trace amounts of six of seven furanocoumarins present in the hostplant. Thus, parasitoids likely encounter furanocoumarins in host hemolymph. Assays of xanthotoxin metabolism in C. sosares failed to show any ability to metabolize this compound. Parasitized Webworms, collected from populations of Heracleum sphondylium in the Netherlands in 2004, were on average 55 % larger by weight than unparasitized individuals. This weight is inclusive of host and parasitoid masses. Absolute rates of detoxification (nmoles min^−1) of five different furanocoumarins were indistinguishable between parasitized and unparasitized ultimate instars, suggesting that the intrinsic rates of metabolism are fixed. Thus, although parasitized larvae are larger, detoxification rates are not commensurate with size; rates in parasitized larvae expressed per gram of larval mass were 25 % lower than in unparasitized larvae.
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characterization and evolution of furanocoumarin inducible cytochrome p450s in the parsnip Webworm depressaria pastinacella
Insect Molecular Biology, 2004Co-Authors: W Li, Arthur R Zangerl, Mary A Schuler, May R BerenbaumAbstract:: Depressaria pastinacella, the parsnip Webworm, a specialist on two genera in the Apiaceae, routinely consumes plant tissues high in furanocoumarin content and is capable of rapid cytochrome P450-mediated detoxification of these compounds. In this study, four cDNAs were cloned from the larval midgut of this insect: two full-length CYP6AB3 and CYP6AE1 cDNAs are closely related to members of the furanocoumarin-metabolizing CYP6B subfamily and two partial CYP9A6 and CYP9A7 cDNAs are related to members of the CYP9A subfamily that have also been linked to the detoxification of xenobiotics. At least one of these P450s (CYP6AB3) is inducible by dietary furanocoumarins, indicating its potential involvement in furanocoumarin metabolism. A homology model of CYP6AB3 was constructed and compared to models of CYP6B1 from the specialist species, Papilio polyxenes, and CYP6B4 from the generalist species, P. glaucus. Structural superpositioning of these models has revealed very high spatial similarity of elements, including the B helix, B'-C loop, I helix and C-terminal domain, within the catalytic sites of these proteins. Most importantly, key amino acid residues that can potentially come into contact with furanocoumarin substrates display conservation in their spatial positioning and side chain polarities. Three of these residues, Val103, Leu113 and Phe118 (numbered according to CYP6AB3), are conserved in all three of these proteins, further implicating CYP6AB3 in furanocoumarin metabolism by parsnip Webworms. Characterization of these P450 cDNAs will allow for functional analyses aimed at elucidating the molecular mechanisms underlying the coevolutionary interactions between this herbivore and its principal host plant.
I S Shayakhmetova - One of the best experts on this subject based on the ideXlab platform.
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stereoselective synthesis of 11 e tetradecen 1 yl acetate sex pheromone of sod Webworm loxostege sticticalis
Russian Journal of General Chemistry, 2009Co-Authors: R N Shakhmaev, A U Ishbaeva, I S ShayakhmetovaAbstract:On the basic of Claisen rearrangement using orthoesters we carried out stereoselective synthesis of 11(E)-tetradecen-1-yl acetate, a sex pheromone of sod Webworm (Loxostege sticticalis), which is a specially dangerous pests of crops.
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Stereoselective synthesis of 11( E )-tetradecen-1-yl acetate—Sex pheromone of sod Webworm ( Loxostege sticticalis )
Russian Journal of General Chemistry, 2009Co-Authors: R N Shakhmaev, A U Ishbaeva, I S ShayakhmetovaAbstract:On the basic of Claisen rearrangement using orthoesters we carried out stereoselective synthesis of 11(E)-tetradecen-1-yl acetate, a sex pheromone of sod Webworm (Loxostege sticticalis), which is a specially dangerous pests of crops.
Hongzhi Wang - One of the best experts on this subject based on the ideXlab platform.
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efficacy of cry1ac protein against gypsy moth and fall Webworm in transgenic poplar populus davidiana populus bolleana by bioassay
Canadian Journal of Plant Science, 2018Co-Authors: Liping Ding, Yajuan Chen, Hongzhi WangAbstract:A modified Bacillus thuringiensis (Bt) cry1Ac gene was introduced into poplar ‘Shanxin’ (Populus davidiana × Populus bolleana) by Agrobacterium-mediated transformation. 17 cry1Ac transgenic lines were regenerated. The integration and expression of cry1Ac gene in these transgenic lines were analyzed by PCR and RT-qPCR, respectively. Variable amounts of cry1Ac mRNA accumulated in different transgenic plants. The expression of Cry1Ac toxin protein in transgenic plants was analyzed by ELISA, the concentration ranged from 0.12 μg•g-1 to 21.00 μg•g-1. The concentration of Cry1Ac protein was highly consistent with mRNA amount in each transgenic line. Leaf section bioassays were conducted using the larvae of both gypsy moth (Lymantria dispar) and fall Webworm (Hyphantria cunea). Those plants, except lines 10 and 11, caused rapid mortality of all gypsy moth and fall Webworm larvae with almost no defoliation, while lines 10 and 11 with Cry1Ac protein concentration of 0.12 μg•g-1 and 0.76 μg•g-1, respectively, provi...
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laboratory evaluation of transgenic populus davidiana populus bolleana expressing cry1ac sck cry1ah3 and cry9aa3 genes against gypsy moth and fall Webworm
PLOS ONE, 2017Co-Authors: Liping Ding, Yajuan Chen, Mi Ni, Jiewei Zhang, Hongzhi WangAbstract:: Transgenic poplar lines 'Shanxin' (Populus davidiana×Populus bolleana) were generated via Agrobacterium-mediated transformation. The transgenic lines carried the expression cassettes of Cry1Ac + SCK, Cry1Ah3, and Cry9Aa3, respectively. The expression levels of the exogenous insect resistance genes in the transgenic lines were determined by Q-PCR and Western blot. Leaves of the transgenic lines were used for insect feeding bioassays on first instar larvae of the gypsy moth (Lymantria dispar) and fall Webworm (Hyphantria cunea). At 5 d of feeding, the mean mortalities of larvae feeding on Cry1Ac + SCK and Cry1Ah3 transgenic poplars leaves were 97% and 91%, while mortality on Cry9Aa3 transgenic lines was about 49%. All gypsy moth and fall Webworm larvae were killed in 7-9 days after feeding on leaves from Cry1Ac + SCK or Cry1Ah3 transgenic poplars, while all the fall Webworm larvae were killed in 11 days and about 80% of gypsy moth larvae were dead in 14 days after feeding on those from Cry9Aa3 transgenic lines. It was concluded that the transgenic lines of Cry1Ac + SCK and Cry1Ah3 were highly toxic to larvae of both insect species while lines with Cry9Aa3 had lower toxicity,and H. cunea larvae are more sensitive to the insecticidal proteins compared to L. dispar. Transgenic poplar lines toxic to L. dispar and H. cunea could be used to provide Lepidoptera pest resistance to selected strains of poplar trees.
R N Shakhmaev - One of the best experts on this subject based on the ideXlab platform.
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stereoselective synthesis of 11 e tetradecen 1 yl acetate sex pheromone of sod Webworm loxostege sticticalis
Russian Journal of General Chemistry, 2009Co-Authors: R N Shakhmaev, A U Ishbaeva, I S ShayakhmetovaAbstract:On the basic of Claisen rearrangement using orthoesters we carried out stereoselective synthesis of 11(E)-tetradecen-1-yl acetate, a sex pheromone of sod Webworm (Loxostege sticticalis), which is a specially dangerous pests of crops.
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Stereoselective synthesis of 11( E )-tetradecen-1-yl acetate—Sex pheromone of sod Webworm ( Loxostege sticticalis )
Russian Journal of General Chemistry, 2009Co-Authors: R N Shakhmaev, A U Ishbaeva, I S ShayakhmetovaAbstract:On the basic of Claisen rearrangement using orthoesters we carried out stereoselective synthesis of 11(E)-tetradecen-1-yl acetate, a sex pheromone of sod Webworm (Loxostege sticticalis), which is a specially dangerous pests of crops.
