1
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Nixon KJA, Parzer HF. Got milkweed? Genetic assimilation as potential source for the evolution of nonmigratory monarch butterfly wing shape. Evol Dev 2024; 26:e12463. [PMID: 37971877 DOI: 10.1111/ede.12463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 09/09/2023] [Accepted: 10/23/2023] [Indexed: 11/19/2023]
Abstract
Monarch butterflies (Danaus plexippus) are well studied for their annual long-distance migration from as far north as Canada to their overwintering grounds in Central Mexico. At the end of the cold season, monarchs start to repopulate North America through short-distance migration over the course of multiple generations. Interestingly, some populations in various tropical and subtropical islands do not migrate and exhibit heritable differences in wing shape and size, most likely an adaptation to island life. Less is known about forewing differences between long- and short-distance migrants in relation to island populations. Given their different migratory behaviors, we hypothesized that these differences would be reflected in wing morphology. To test this, we analyzed forewing shape and size of three different groups: nonmigratory, lesser migratory (migrate short-distances), and migratory (migrate long-distances) individuals. Significant differences in shape appear in all groups using geometric morphometrics. As variation found between migratory and lesser migrants has been shown to be caused by phenotypic plasticity, and lesser migrants develop intermediate forewing shapes between migratory and nonmigratory individuals, we suggest that genetic assimilation might be an important mechanism to explain the heritable variation found between migratory and nonmigratory populations. Additionally, our research confirms previous studies which show that forewing size is significantly smaller in nonmigratory populations when compared to both migratory phenotypes. Finally, we found sexual dimorphism in forewing shape in all three groups, but for size in nonmigratory populations only. This might have been caused by reduced constraints on forewing size in nonmigratory populations.
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Affiliation(s)
- Kyra J A Nixon
- Department of Biological Sciences, Fairleigh Dickinson University, Madison, New Jersey, USA
| | - Harald F Parzer
- Department of Biological Sciences, Fairleigh Dickinson University, Madison, New Jersey, USA
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2
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Parker AL, Albright A, Kingsolver JG, Legault G. Predicting age and mass at maturity from feeding behavior and diet in Manduca sexta: An empirical test of a life history model. Ecol Evol 2023; 13:e9848. [PMID: 36844672 PMCID: PMC9944182 DOI: 10.1002/ece3.9848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Feeding for most animals involves bouts of active ingestion alternating with bouts of no ingestion. In insects, the temporal patterning of bouts varies widely with resource quality and is known to affect growth, development time, and fitness. However, the precise impacts of resource quality and feeding behavior on insect life history traits are poorly understood. To explore and better understand the connections between feeding behavior, resource quality, and insect life history traits, we combined laboratory experiments with a recently proposed mechanistic model of insect growth and development for a larval herbivore, Manduca sexta. We ran feeding trials for 4th and 5th instar larvae across different diet types (two hostplants and artificial diet) and used these data to parameterize a joint model of age and mass at maturity that incorporates both insect feeding behavior and hormonal activity. We found that the estimated durations of both feeding and nonfeeding bouts were significantly shorter on low-quality than on high-quality diets. We then explored how well the fitted model predicted historical out-of-sample data on age and mass of M. sexta. We found that the model accurately described qualitative outcomes for the out-of-sample data, notably that a low-quality diet results in reduced mass and later age at maturity compared with high-quality diets. Our results clearly demonstrate the importance of diet quality on multiple components of insect feeding behavior (feeding and nonfeeding) and partially validate a joint model of insect life history. We discuss the implications of these findings with respect to insect herbivory and discuss ways in which our model could be improved or extended to other systems.
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Affiliation(s)
- Anna L. Parker
- University of North Carolina – Chapel HillChapel HillNorth CarolinaUSA
| | - Anna Albright
- University of North Carolina – Chapel HillChapel HillNorth CarolinaUSA
| | | | - Geoffrey Legault
- University of North Carolina – Chapel HillChapel HillNorth CarolinaUSA
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3
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Rubiano-Buitrago P, Pradhan S, Paetz C, Rowland HM. New Structures, Spectrometric Quantification, and Inhibitory Properties of Cardenolides from Asclepias curassavica Seeds. Molecules 2022; 28:molecules28010105. [PMID: 36615300 PMCID: PMC9822358 DOI: 10.3390/molecules28010105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/14/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant-herbivore and predator-prey interactions, based on their ability to inhibit the membrane-bound Na+/K+-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4'-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3'-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5-10). We test the in vitro inhibition of these compounds on the sensitive porcine Na+/K+-ATPase. The least inhibitory compound was also the most abundant in the seeds-4'-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant-herbivore interactions.
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Affiliation(s)
- Paola Rubiano-Buitrago
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Correspondence: (P.R.-B.); (H.M.R.)
| | - Shrikant Pradhan
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
| | - Christian Paetz
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
| | - Hannah M. Rowland
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Correspondence: (P.R.-B.); (H.M.R.)
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4
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Mohammadi S, Yang L, Bulbert M, Rowland HM. Defence mitigation by predators of chemically defended prey integrated over the predation sequence and across biological levels with a focus on cardiotonic steroids. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220363. [PMID: 36133149 PMCID: PMC9449480 DOI: 10.1098/rsos.220363] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/17/2022] [Indexed: 05/10/2023]
Abstract
Predator-prey interactions have long served as models for the investigation of adaptation and fitness in natural environments. Anti-predator defences such as mimicry and camouflage provide some of the best examples of evolution. Predators, in turn, have evolved sensory systems, cognitive abilities and physiological resistance to prey defences. In contrast to prey defences which have been reviewed extensively, the evolution of predator counter-strategies has received less attention. To gain a comprehensive view of how prey defences can influence the evolution of predator counter-strategies, it is essential to investigate how and when selection can operate. In this review we evaluate how predators overcome prey defences during (i) encounter, (ii) detection, (iii) identification, (iv) approach, (v) subjugation, and (vi) consumption. We focus on prey that are protected by cardiotonic steroids (CTS)-defensive compounds that are found in a wide range of taxa, and that have a specific physiological target. In this system, coevolution is well characterized between specialist insect herbivores and their host plants but evidence for coevolution between CTS-defended prey and their predators has received less attention. Using the predation sequence framework, we organize 574 studies reporting predators overcoming CTS defences, integrate these counter-strategies across biological levels of organization, and discuss the costs and benefits of attacking CTS-defended prey. We show that distinct lineages of predators have evolved dissecting behaviour, changes in perception of risk and of taste perception, and target-site insensitivity. We draw attention to biochemical, hormonal and microbiological strategies that have yet to be investigated as predator counter-adaptations to CTS defences. We show that the predation sequence framework will be useful for organizing future studies of chemically mediated systems and coevolution.
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Affiliation(s)
- Shabnam Mohammadi
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
- Institut für Zell- und Systembiologie der Tiere, Universität Hamburg, Hamburg, Germany
- Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lu Yang
- Wellcome Sanger Institute, Cambridge, UK
| | - Matthew Bulbert
- Department of Biological Sciences, Macquarie University North Ryde, New South Wales, Australia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, University of Oxford Brookes, Oxford, UK
- Max Planck Institute for Chemical Ecology, Jena, Germany
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5
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Mohammadi S, Yang L, Bulbert M, Rowland HM. Defence mitigation by predators of chemically defended prey integrated over the predation sequence and across biological levels with a focus on cardiotonic steroids. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220363. [PMID: 36133149 DOI: 10.6084/m9.figshare.c.6168216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/17/2022] [Indexed: 05/25/2023]
Abstract
Predator-prey interactions have long served as models for the investigation of adaptation and fitness in natural environments. Anti-predator defences such as mimicry and camouflage provide some of the best examples of evolution. Predators, in turn, have evolved sensory systems, cognitive abilities and physiological resistance to prey defences. In contrast to prey defences which have been reviewed extensively, the evolution of predator counter-strategies has received less attention. To gain a comprehensive view of how prey defences can influence the evolution of predator counter-strategies, it is essential to investigate how and when selection can operate. In this review we evaluate how predators overcome prey defences during (i) encounter, (ii) detection, (iii) identification, (iv) approach, (v) subjugation, and (vi) consumption. We focus on prey that are protected by cardiotonic steroids (CTS)-defensive compounds that are found in a wide range of taxa, and that have a specific physiological target. In this system, coevolution is well characterized between specialist insect herbivores and their host plants but evidence for coevolution between CTS-defended prey and their predators has received less attention. Using the predation sequence framework, we organize 574 studies reporting predators overcoming CTS defences, integrate these counter-strategies across biological levels of organization, and discuss the costs and benefits of attacking CTS-defended prey. We show that distinct lineages of predators have evolved dissecting behaviour, changes in perception of risk and of taste perception, and target-site insensitivity. We draw attention to biochemical, hormonal and microbiological strategies that have yet to be investigated as predator counter-adaptations to CTS defences. We show that the predation sequence framework will be useful for organizing future studies of chemically mediated systems and coevolution.
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Affiliation(s)
- Shabnam Mohammadi
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
- Institut für Zell- und Systembiologie der Tiere, Universität Hamburg, Hamburg, Germany
- Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lu Yang
- Wellcome Sanger Institute, Cambridge, UK
| | - Matthew Bulbert
- Department of Biological Sciences, Macquarie University North Ryde, New South Wales, Australia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, University of Oxford Brookes, Oxford, UK
- Max Planck Institute for Chemical Ecology, Jena, Germany
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6
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Greenstein L, Steele C, Taylor CM. Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis. PLoS One 2022; 17:e0269701. [PMID: 35700160 PMCID: PMC9197062 DOI: 10.1371/journal.pone.0269701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/25/2022] [Indexed: 11/26/2022] Open
Abstract
The preference-performance hypothesis explains host specificity in phytophagous insects, positing that host plants chosen by adults confer the greatest larval fitness. However, adults sometimes oviposit on plants supporting low larval success because the components of host specificity (adult preference, plant palatability, and larval survival) are non-binary and not necessarily correlated. Palatability (willingness to eat) is governed by chemical cues and physical barriers such as trichomes, while survival (ability to complete development) depends upon nutrition and toxicity. Absence of a correlation between the components of host specificity results in low-performance hosts supporting limited larval development. Most studies of specificity focus on oviposition behavior leaving the importance and basis of palatability and survival under-explored. We conducted a comprehensive review of 127 plant species that have been claimed or tested to be hosts for the monarch butterfly Danaus plexippus to classify them as non-hosts, low performance, or high performance. We performed a meta-analysis to test if performance status could be explained by properties of neurotoxic cardenolides or trichome density. We also conducted a no-choice larval feeding experiment to identify causes of low performance. We identified 34 high performance, 42 low performance, 33 non-hosts, and 18 species with unsubstantiated claims. Mean cardenolide concentration was greater in high- than low-performance hosts and a significant predictor of host status, suggesting possible evolutionary trade-offs in monarch specialization. Other cardenolide properties and trichome density were not significant predictors of host status. In the experiment, we found, of the 62% of larvae that attempted to eat low-performance hosts, only 3.5% survived to adult compared to 85% of those on the high-performance host, demonstrating that multiple factors affect larval host plant specificity. Our study is the first to classify all known host plants for monarchs and has conservation implications for this threatened species.
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Affiliation(s)
- Lewis Greenstein
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
- * E-mail:
| | - Christen Steele
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
| | - Caz M. Taylor
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
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7
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Saul-Gershenz L, Grodsky SM, Hernandez RR. Ecology of the Western Queen Butterfly Danaus gilippus thersippus (Lepidoptera: Nymphalidae) in the Mojave and Sonoran Deserts. INSECTS 2020; 11:insects11050315. [PMID: 32438741 PMCID: PMC7290759 DOI: 10.3390/insects11050315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 01/09/2023]
Abstract
The purpose of this study was to assess the ecological knowledge surrounding the western queen butterfly, Danaus gilippus thersippus (H. Bates). Specifically, our objectives were to synthesize existing data and knowledge on the ecology of the queen and use results of this assessment to inform the direction of future research on this understudied species. We identified six core areas for assessment: distribution, the biodiversity of plant resources, western queen and their host plant phenology, chemical ecology, and four key life history traits. We mapped the distribution of D. g. thersippus from museum specimen records, citizen science (e.g., iNaturalist) and image sharing app-based observations, along with other observational data enumerating all current known plant resources and long-range movements. We assembled 14 larval food plants, six pyrrolizidine alkaloids plants and six nectar plants distributed in the western Mojave and Sonoran Desert regions of the United States and Baja California. We report on its phenology and its long-range movement. Butterfly species have declined across the western US, and western monarch populations have declined by 97%. Danaus g. thersippus has received little research attention compared with its famous congener D. plexippus L. Danaus g. thersippus' desert distribution may be at its temperature limits for the species distribution and for its rare host plant Asclepias nyctaginifolia.
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Affiliation(s)
- Leslie Saul-Gershenz
- Wild Energy Initiative, John Muir Institute of the Environment, University of California, Davis, 1 Shields Ave., Davis, CA 95616, USA; (S.M.G.); (R.R.H.)
- Department of Entomology and Nematology, 1 Shields Ave., University of California, Davis, Davis, CA 95616, USA
- USDA-ARS, Invasive Species and Pollinator Health Research Unit, 3026 Bee Biology Rd, Davis, CA 95616, USA
- Correspondence:
| | - Steven M. Grodsky
- Wild Energy Initiative, John Muir Institute of the Environment, University of California, Davis, 1 Shields Ave., Davis, CA 95616, USA; (S.M.G.); (R.R.H.)
| | - Rebecca R. Hernandez
- Wild Energy Initiative, John Muir Institute of the Environment, University of California, Davis, 1 Shields Ave., Davis, CA 95616, USA; (S.M.G.); (R.R.H.)
- Department of Land, Air, and Water Resources, 1 Shields Ave., University of California, Davis, Davis, CA 95616, USA
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8
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Huang W, Bont Z, Hervé MR, Robert CAM, Erb M. Impact of Seasonal and Temperature-Dependent Variation in Root Defense Metabolites on Herbivore Preference in Taraxacum officinale. J Chem Ecol 2019; 46:63-75. [PMID: 31832894 PMCID: PMC6954900 DOI: 10.1007/s10886-019-01126-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/08/2019] [Accepted: 11/18/2019] [Indexed: 12/25/2022]
Abstract
Plants experience seasonal fluctuations in abiotic and biotic factors such as herbivore attack rates. If and how root defense expression co-varies with seasonal fluctuations in abiotic factors and root herbivore attack rates is not well understood. Here, we evaluated seasonal changes in defensive root latex chemistry of Taraxacum officinale plants in the field and correlated the changes with seasonal fluctuations in abiotic factors and damage potential by Melolontha melolontha, a major natural enemy of T. officinale. We then explored the causality and consequences of these relationships under controlled conditions. The concentration of the defensive sesquiterpene lactone taraxinic acid β-D glucopyranosyl ester (TA-G) varied substantially over the year and was most strongly correlated to mean monthly temperature. Both temperature and TA-G levels were correlated with annual fluctuations in potential M. melolontha damage. Under controlled conditions, plants grown under high temperature produced more TA-G and were less attractive for M. melolontha. However, temperature-dependent M. melolontha feeding preferences were not significantly altered in TA-G deficient transgenic lines. Our results suggest that fluctuations in temperature leads to variation in the production of a root defensive metabolites that co-varies with expected attack of a major root herbivore. Temperature-dependent herbivore preference, however, is likely to be modulated by other phenotypic alterations.
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Affiliation(s)
- Wei Huang
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland. .,CAS Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, Hubei, China.
| | - Zoe Bont
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Maxime R Hervé
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland.,Inra, Agrocampus Ouest, IGEPP - UMR-A 1349, University of Rennes, F-35000, Rennes, France
| | - Christelle A M Robert
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland.
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9
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Yang LH, Cenzer ML. Seasonal windows of opportunity in milkweed–monarch interactions. Ecology 2019; 101:e02880. [DOI: 10.1002/ecy.2880] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/25/2019] [Accepted: 08/02/2019] [Indexed: 01/11/2023]
Affiliation(s)
- Louie H. Yang
- Department of Entomology and Nematology University of California Davis California 95616 USA
| | - Meredith L. Cenzer
- Department of Entomology and Nematology University of California Davis California 95616 USA
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10
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Oberhauser KS, Alonso A, Malcolm SB, Williams EH, Zalucki MP. Lincoln Brower, Champion for Monarchs. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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11
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El-Mallakh RS, Brar KS, Yeruva RR. Cardiac Glycosides in Human Physiology and Disease: Update for Entomologists. INSECTS 2019; 10:E102. [PMID: 30974764 PMCID: PMC6523104 DOI: 10.3390/insects10040102] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 12/12/2022]
Abstract
Cardiac glycosides, cardenolides and bufadienolides, are elaborated by several plant or animal species to prevent grazing or predation. Entomologists have characterized several insect species that have evolved the ability to sequester these glycosides in their tissues to reduce their palatability and, thus, reduce predation. Cardiac glycosides are known to interact with the sodium- and potassium-activated adenosine triphosphatase, or sodium pump, through a specific receptor-binding site. Over the last couple of decades, and since entomologic studies, it has become clear that mammals synthesize endogenous cardenolides that closely resemble or are identical to compounds of plant origin and those sequestered by insects. The most important of these are ouabain-like compounds. These compounds are essential for the regulation of normal ionic physiology in mammals. Importantly, at physiologic picomolar or nanomolar concentrations, endogenous ouabain, a cardenolide, stimulates the sodium pump, activates second messengers, and may even function as a growth factor. This is in contrast to the pharmacologic or toxic micromolar or milimolar concentrations achieved after consumption of exogenous cardenolides (by consuming medications, plants, or insects), which inhibit the pump and result in either a desired medical outcome, or the toxic consequence of sodium pump inhibition.
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Affiliation(s)
- Rif S El-Mallakh
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
| | - Kanwarjeet S Brar
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
| | - Rajashekar Reddy Yeruva
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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12
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Züst T, Petschenka G, Hastings AP, Agrawal AA. Toxicity of Milkweed Leaves and Latex: Chromatographic Quantification Versus Biological Activity of Cardenolides in 16 Asclepias Species. J Chem Ecol 2018; 45:50-60. [PMID: 30523520 DOI: 10.1007/s10886-018-1040-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/18/2018] [Accepted: 11/27/2018] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- Tobias Züst
- Institute of Plant Sciences, University of Bern, 3013, Bern, Switzerland.
| | - Georg Petschenka
- Institut für Insektenbiotechnologie, Justus-Liebig-Universität Giessen, 35392, Giessen, Germany
| | - Amy P Hastings
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA.,Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
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13
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Camazine S, Lupo AT. Labile Toxic Compounds of the Lactarii: The Role of the Laticiferous Hyphae as a Storage Depot for Precursors of Pungent Dialdehydes. Mycologia 2018. [DOI: 10.1080/00275514.1984.12023846] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Scott Camazine
- Division of Biological Sciences, Section of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
| | - Andrew T. Lupo
- Department of Chemistry, Cornell University, Ithaca, New York 14853
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14
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Bramer C, Schweizer C, Dobler S. Cardenolide-defended milkweed bugs do not evoke learning inNephila senegalensisspiders. Ethology 2018. [DOI: 10.1111/eth.12757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Christiane Bramer
- Johann-Friedrich-Blumenbach-Institut; Georg-August-Universität; Göttingen Germany
- Institut für Zoologie; Universität Hamburg; Hamburg Germany
| | | | - Susanne Dobler
- Institut für Zoologie; Universität Hamburg; Hamburg Germany
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15
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Gols R, van Dam NM, Reichelt M, Gershenzon J, Raaijmakers CE, Bullock JM, Harvey JA. Seasonal and herbivore-induced dynamics of foliar glucosinolates in wild cabbage ( Brassica oleracea). CHEMOECOLOGY 2018; 28:77-89. [PMID: 29904237 PMCID: PMC5988764 DOI: 10.1007/s00049-018-0258-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 05/03/2018] [Indexed: 12/02/2022]
Abstract
Levels of plant secondary metabolites are not static and often change in relation to plant ontogeny. They also respond to abiotic and biotic changes in the environment, e.g., they often increase in response to biotic stress, such as herbivory. In contrast with short-lived annual plant species, especially those with growing periods of less than 2-3 months, investment in defensive compounds of vegetative tissues in biennial and perennial species may also vary over the course of an entire growing season. In garden experiments, we investigated the dynamics of secondary metabolites, i.e. glucosinolates (GSLs) in the perennial wild cabbage (Brassica oleracea), which was grown from seeds originating from three populations that differ in GSL chemistry. We compared temporal long-term dynamics of GSLs over the course of two growing seasons and short-term dynamics in response to herbivory by Pieris rapae caterpillars in a more controlled greenhouse experiment. Long-term dynamics differed for aliphatic GSLs (gradual increase from May to December) and indole GSLs (rapid increase until mid-summer after which concentrations decreased or stabilized). In spring, GSL levels in new shoots were similar to those found in the previous year. Short-term dynamics in response to herbivory primarily affected indole GSLs, which increased during the 2-week feeding period by P. rapae. Herbivore-induced changes in the concentrations of aliphatic GSLs were population-specific and their concentrations were found to increase in primarily one population only. We discuss our results considering the biology and ecology of wild cabbage.
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Affiliation(s)
- Rieta Gols
- Laboratory of Entomology, Wageningen University & Research, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Nicole M. van Dam
- German Centre for Integrative Biodiversity Research, Leipzig, Germany
| | | | | | | | | | - Jeffrey A. Harvey
- Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands
- Department of Ecological Sciences, Section Animal Ecology, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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16
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Bustos-Segura C, Padovan A, Kainer D, Foley WJ, Külheim C. Transcriptome analysis of terpene chemotypes of Melaleuca alternifolia across different tissues. PLANT, CELL & ENVIRONMENT 2017; 40:2406-2425. [PMID: 28771760 DOI: 10.1111/pce.13048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 06/07/2023]
Abstract
Plant chemotypes or chemical polymorphisms are defined by discrete variation in secondary metabolites within a species. This variation can have consequences for ecological interactions or the human use of plants. Understanding the molecular basis of chemotypic variation can help to explain how variation of plant secondary metabolites is controlled. We explored the transcriptomes of the 3 cardinal terpene chemotypes of Melaleuca alternifolia in young leaves, mature leaves, and stem and compared transcript abundance to variation in the constitutive profile of terpenes. Leaves from chemotype 1 plants (dominated by terpinen-4-ol) show a similar pattern of gene expression when compared to chemotype 5 plants (dominated by 1,8-cineole). Only terpene synthases in young leaves were differentially expressed between these chemotypes, supporting the idea that terpenes are mainly synthetized in young tissue. Chemotype 2 plants (dominated by terpinolene) show a greater degree of differential gene expression compared to the other chemotypes, which might be related to the isolation of plant populations that exhibit this chemotype and the possibility that the terpinolene synthase gene in M. alternifolia was derived by introgression from a closely related species, Melaleuca trichostachya. By using multivariate analyses, we were able to associate terpenes with candidate terpene synthases.
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Affiliation(s)
- Carlos Bustos-Segura
- Division of Evolution and Ecology, Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
- Laboratory of Evolutionary Entomology, Institute of Biology, University of Neuchatel, Neuchatel, 2000, Switzerland
| | - Amanda Padovan
- Division of Evolution and Ecology, Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
| | - David Kainer
- Division of Evolution and Ecology, Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
| | - William J Foley
- Division of Evolution and Ecology, Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
| | - Carsten Külheim
- Division of Evolution and Ecology, Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
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17
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Keith RA, Mitchell-Olds T. Testing the optimal defense hypothesis in nature: Variation for glucosinolate profiles within plants. PLoS One 2017; 12:e0180971. [PMID: 28732049 PMCID: PMC5521783 DOI: 10.1371/journal.pone.0180971] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/24/2017] [Indexed: 11/19/2022] Open
Abstract
Plants employ highly variable chemical defenses against a broad community of herbivores, which vary in their susceptibilities to specific compounds. Variation in chemical defenses within the plant has been found in many species; the ecological and evolutionary influences on this variation, however, are less well-understood. One central theory describing the allocation of defenses in the plant is the Optimal Defense Hypothesis (ODH), which predicts that defenses will be concentrated in tissues that are of high fitness value to the plant. Although the ODH has been repeatedly supported within vegetative tissues, few studies have compared vegetative and reproductive tissues, and the results have not been conclusive. We quantified variation in glucosinolate profile and tissue value between vegetative and reproductive tissues in Boechera stricta, a close relative of Arabidopsis. B. stricta manufactures glucosinolates, a set of defensive compounds that vary genetically and are straightforward to quantify. Genetic diversity in glucosinolate profile has been previously demonstrated to be important to both herbivory and fitness in B. stricta; however, the importance of glucosinolate variation among tissues has not. Here, we investigate whether allocation of glucosinolates within the plant is consistent with the ODH. We used both clipping experiments on endogenous plants and ambient herbivory in a large-scale transplant experiment at three sites to quantify fitness effects of loss of rosette leaves, cauline leaves, and flowers and fruits. We measured glucosinolate concentration in leaves and fruits in the transplant experiment, and asked whether more valuable tissues were more defended. We also investigated within-plant variation in other aspects of the glucosinolate profile. Our results indicated that damage to fruits had a significantly larger effect on overall fitness than damage to leaves, and that fruits had much higher concentrations of glucosinolates, supporting the ODH. This is, to the best of our knowledge, the first study to explicitly compare both tissue value and chemical defense concentrations between vegetative and reproductive tissues under natural conditions.
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Affiliation(s)
- Rose A. Keith
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
- Biology Department, Duke University, Durham, North Carolina, United States of America
| | - Thomas Mitchell-Olds
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
- Biology Department, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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18
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Farrell B, Mitter C. PHYLOGENESIS OF INSECT/PLANT INTERACTIONS: HAVE
PHYLLOBROTICA
LEAF BEETLES (CHRYSOMELIDAE) AND THE LAMIALES DIVERSIFIED IN PARALLEL? Evolution 2017; 44:1389-1403. [DOI: 10.1111/j.1558-5646.1990.tb03834.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/1989] [Accepted: 01/10/1990] [Indexed: 11/28/2022]
Affiliation(s)
- Brian Farrell
- Department of Entomology University of Maryland College Park MD 20742 USA
| | - Charles Mitter
- Department of Entomology University of Maryland College Park MD 20742 USA
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19
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Morsy N. Quantitative estimations of the abundant constituents of alotropis procera. MAIN GROUP CHEMISTRY 2017. [DOI: 10.3233/mgc-160218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Nagy Morsy
- Department of Chemistry, Faculty of Sciences and Arts, Khulais, University of Jeddah, Kingdom of Saudi Arabia
- National Research Centre, Department of Chemistry of Natural Compounds, El-bohouth St., Dokki, Cairo, Egypt
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20
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Pierce AA, de Roode JC, Tao L. Comparative genetics of Na +/K +-ATPase in monarch butterfly populations with varying host plant toxicity. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12797] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amanda A. Pierce
- Department of Biology; Emory University; 1510 Clifton Road Atlanta GA 30322 USA
| | - Jacobus C. de Roode
- Department of Biology; Emory University; 1510 Clifton Road Atlanta GA 30322 USA
| | - Leiling Tao
- Department of Biology; Emory University; 1510 Clifton Road Atlanta GA 30322 USA
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21
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Baas W. INVESTIGATIONS ON LEAF WAXES III* PENTACYCLIC TRITERPENES, SECO-TRITERPENES AND NON-VOLATILE ALIPHATICS OF FOUR HOYA SPECIES AND FICUS BENJAMINA IN RELATION TO LEAF AGE. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/j.1438-8677.1982.tb01662.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- W.J. Baas
- Botanisch Laboratorium; Rijksuniversiteit Utrecht; Lange Nieuwstraat 106 3512 PN Utrecht
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22
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Brower LP, Seiber JN, Nelson CJ, Lynch SP, Holland MM. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa. J Chem Ecol 2013; 10:601-39. [PMID: 24318600 DOI: 10.1007/bf00994224] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/1983] [Revised: 07/21/1983] [Indexed: 11/30/2022]
Abstract
The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 μg of cardenolide per 0.1 g dry weight with a mean of 90 μg per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 μg of cardenolide per 0.1 g dry weight with a mean of 179 μg. Total cardenolide per butterfly ranged from 54 to 1279 μg with a mean of 319 μg. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED50 units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications. About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.
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Affiliation(s)
- L P Brower
- Department of Zoology, Univerisly of Florida, 32611, Gainesville, Florida
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23
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Marty MA, Krieger RI. Metabolism of uscharidin, a milkweed cardenolide, by tissue homogenates of monarch butterfly larvae,Danaus plexippus L. J Chem Ecol 2013; 10:945-56. [PMID: 24318786 DOI: 10.1007/bf00987975] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/1983] [Revised: 09/22/1983] [Indexed: 11/24/2022]
Abstract
Midgut and fat body homogenates of monarch butterfly larvae,Danaus plexippus L. (Lepidoptera:Danaidae), were examined for microsomal monooxygenase activity usingp-chloro-N-methylanilineN-demethylation and for the ability to metabolize a milkweed (Asclepias spp.) cardenolide (C23 steroid glycoside), uscharidin. All homogenates tested had bothN-demethylation and uscharidin biotransformation activities. Both transformations required NADPH. The monooxygenase inhibitors sesamex, SKF525A, and carbon monoxide inhibitedN-demethylation but not uscharidin biotransformation. Subsequent subcellular fractionation revealed the uscharidin biotransformation occurs in the soluble fraction and not the microsomal fraction, whileN-demethylation occurs in the microsomal fraction and not the soluble fraction. The larval NADPH-dependent microsomal monooxygenase apparently is not involved in the metabolism of uscharidin.
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Affiliation(s)
- M A Marty
- Department of Environmental Toxicology, University of California Davis, 95616, California
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24
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Lynch SP, Martin RA. Cardenolide content and thin-layer chromatography profiles of monarch butterflies,danaus plexippus L., and their larval host-plant milkweed,asclepias viridis walt., in northwestern louisiana. J Chem Ecol 2013; 13:47-70. [PMID: 24301359 DOI: 10.1007/bf01020351] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/1985] [Accepted: 01/13/1986] [Indexed: 11/28/2022]
Abstract
This paper is the first in a series on cardenolide fingerprinting of monarch butterflies and their host-plant milkweeds in the eastern United States. Spectrophotometric determinations of the gross cardenolide content of 60Asclepias viridis plants in northwestern Louisiana indicate a positively skewed variation ranging from 95 to 432 υg/0.1 g dry weight with a mean of 245 υg/0.1 g. Butterflies reared individually on these plants contained a normal cardenolide distribution ranging from 73 to 591 υg/0.1 g dry weight with a mean of 337 υg/0.1 g. The uptake of cardenolide by the butterflies best fit a logarithmic function of the plant concentration. Female monarchs (385 υg/0.l g) contained significantly greater mean cardenolide concentrations than did males (287 υg/0.1 g). No indications of a metabolic cost for either cardenolide ingestion or storage were adduced from size or dry weight data. Thin-layer chromatograms of 24 individual plant-butterfly pairs developed in two solvent systems resolved 21 individual spots in the plants and 15 in the butterflies.A. viridis plants appear to contain several relatively nonpolar cardenolides of the calotropagenin series which are metabolized to the more polar 3'-hydroxy derivatives calactin and calotropin as well as to calotropagenin in the butterflies. The epoxy cardenolides labriformin and labriformidin were absent, although desglucosyrioside (a 3'-hydroxy derivative) appeared present in both plants and butterflies. Quantitative evaluation of theR f values, spot intensities, and probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint clearly distinct from those previously established for monarchs reared on otherAsclepias species, supporting the use of fingerprints to make ecological predictions concerning larval host-plant utilization.A. viridis is the predominant early spring milkweed throughout most of the south central United States and may be important in providing chemical protection to spring and early summer generation monarchs in the eastern United States.
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Affiliation(s)
- S P Lynch
- Department of Biological Sciences, Louisiana State University, 71115, Shreveport, Louisiana
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25
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Martin RA, Lynch SP. Cardenolide content and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus L., and their larval host-plant milkweed,Asclepias asperula subsp.Capricornu (woods.) woods., in north central Texas. J Chem Ecol 2013; 14:295-318. [PMID: 24277011 DOI: 10.1007/bf01022548] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/1986] [Accepted: 02/02/1987] [Indexed: 11/29/2022]
Abstract
This paper is the second in a series on cardenolide fingerprinting of monarch butterflies and their host-plant milkweeds in the eastern United States. Spectrophotometric determinations of the gross cardenolide content ofAsclepias asperula plants in north central Texas indicated wide variation ranging from 341 to 1616 μg/0.1 g dry weight. The mean plant cardenolide concentration (886 μg/0.1 g) is the highest for any milkweed species on which monarch cardenolide profiles have been produced. Forty-one butterflies reared individually on these plants contained a skewed distribution of cardenolide concentrations ranging from 231 to 515 μg/0. 1 g dry weight with a mean of 363μg/0.1 g. The uptake of cardenolide by the butterflies was independent of plant concentration, suggesting that saturation occurs in cardenolide sequestration by monarchs when feeding on cardenolide-rich host-plants. Female monarchs contained significantly greater mean cardenolide concentrations (339 μg/0.1 g) than did males (320 μg/0.1 g). The mean dry weight of the male butterflies (0.211 g) was significantly greater than the female mean (0.191) so that the mean total cardenolide contents of males (675 fig) and females (754 μg) were not significantly different. Butterfly size was not significantly correlated to butterfly cardenolide concentration when differences due to sex and individual host-plant concentration were removed. Thin-layer chrornatograms of 24 individual plant-butterfly pairs developed in two solvent systems resolved 22 individual spots in the plants and 15 in the butterflies.A. asperula plants appear to contain several relatively nonpolar cardenolides of the calotropagenin series which are metabolized to more polar derivatives in the butterflies. Quantitative evaluation of theR f values, spot intensities, and probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint clearly distinct from those previously established for monarchs reared on otherAsclepias species. Our data support the use of fingerprints to make ecological predictions concerning larval host-plant utilization.A. asperula subsp.capricornu andA. viridis Walt, are the predominant early spring milkweeds throughout most of the south central United States. Cardenolide-rich monarchs reared on these two species may be instrumental in establishing and reinforcing visual avoidance of adults by naive predators throughout their spring and summer breeding cycle in eastern North America.
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Affiliation(s)
- R A Martin
- Department of Chemistry, Louisiana State University, 71115, Shreveport, Louisiana
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26
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Palatability of aposematic queen butterflies (Danaus gilippus) feeding onSarcostemma clausum (Asclepiadaceae) in Florida. J Chem Ecol 2013; 17:1593-610. [PMID: 24257883 DOI: 10.1007/bf00984691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/1990] [Accepted: 03/04/1991] [Indexed: 10/25/2022]
Abstract
Queen butterflies (Danaus gilippus) are generally considered unpalatable to predators because they sequester and store toxic cardenolides from their larval food plants. However, a major queen food plant in Florida, the asclepiadaceous vineSarcostemma clausum, is shown here to be a very poor cardenolide source, and queens reared on this plant contain no detectable cardenolide. A direct evaluation of queen palatability using red-winged blackbirds indicates thatS. clausum-reared butterflies are essentially palatable to these predators (85% of abdomens entirely eaten), indicating little protection from either cardenolides, other sequestered phytochemicals, or de novo defensive compounds. Wild-caught queens that presumably fed as larvae uponS. clausum and also had access to adult-obtained chemicals, such as pyrrolizidine alkaloids (PAs), were relatively palatable as well (77% of abdomens eaten); they did not differ significantly in palatability from the labreared butterflies. Together, these findings suggest that; (1)S. clausumfed queens are poorly defended against some avian predators, and (2) for the particular queen sample examined, PAs do not contribute substantially to unpalatability. The discovery thatS. clausum-feeding queens are essentially palatable is of additional significance because it compels a reassessment of the classic mimicry relationship between queen and viceroy butterflies. Viceroys have been shown recently to be moderately unpalatable; therefore, the established roles of model and mimic may be reversed in some cases.
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27
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Whitehead SR, Jeffrey CS, Leonard MD, Dodson CD, Dyer LA, Bowers MD. Patterns of Secondary Metabolite Allocation to Fruits and Seeds in Piper reticulatum. J Chem Ecol 2013; 39:1373-84. [DOI: 10.1007/s10886-013-0362-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 09/27/2013] [Accepted: 10/15/2013] [Indexed: 11/24/2022]
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28
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Vannette RL, Hunter MD, Rasmann S. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species. FRONTIERS IN PLANT SCIENCE 2013; 4:361. [PMID: 24065971 PMCID: PMC3776932 DOI: 10.3389/fpls.2013.00361] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/26/2013] [Indexed: 05/23/2023]
Abstract
Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)-which all produce toxic cardenolides-with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense.
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Affiliation(s)
- Rachel L. Vannette
- Biology Department, Stanford UniversityStanford, CA, USA
- Department of Ecology and Evolutionary Biology, University of MichiganAnn Arbor, MI, USA
| | - Mark D. Hunter
- Department of Ecology and Evolutionary Biology, University of MichiganAnn Arbor, MI, USA
| | - Sergio Rasmann
- Department of Ecology and Evolutionary Biology, University of LausanneLausanne, Switzerland
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29
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Manson JS, Rasmann S, Halitschke R, Thomson JD, Agrawal AA. Cardenolides in nectar may be more than a consequence of allocation to other plant parts: a phylogenetic study ofAsclepias. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.02039.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jessamyn S. Manson
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto; ON; M5S 3B2; Canada
| | - Sergio Rasmann
- Department of Ecology and Evolution; University of Lausanne; Lausanne; CH - 1015; Switzerland
| | - Rayko Halitschke
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca; NY; 14853; USA
| | - James D. Thomson
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto; ON; M5S 3B2; Canada
| | - Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca; NY; 14853; USA
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30
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Agrawal AA, Petschenka G, Bingham RA, Weber MG, Rasmann S. Toxic cardenolides: chemical ecology and coevolution of specialized plant-herbivore interactions. THE NEW PHYTOLOGIST 2012; 194:28-45. [PMID: 22292897 DOI: 10.1111/j.1469-8137.2011.04049.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cardenolides are remarkable steroidal toxins that have become model systems, critical in the development of theories for chemical ecology and coevolution. Because cardenolides inhibit the ubiquitous and essential animal enzyme Na⁺/K⁺-ATPase, most insects that feed on cardenolide-containing plants are highly specialized. With a huge diversity of chemical forms, these secondary metabolites are sporadically distributed across 12 botanical families, but dominate the Apocynaceae where they are found in > 30 genera. Studies over the past decade have demonstrated patterns in the distribution of cardenolides among plant organs, including all tissue types, and across broad geographic gradients within and across species. Cardenolide production has a genetic basis and is subject to natural selection by herbivores. In addition, there is strong evidence for phenotypic plasticity, with the biotic and abiotic environment predictably impacting cardenolide production. Mounting evidence indicates a high degree of specificity in herbivore-induced cardenolides in Asclepias. While herbivores of cardenolide-containing plants often sequester the toxins, are aposematic, and possess several physiological adaptations (including target site insensitivity), there is strong evidence that these specialists are nonetheless negatively impacted by cardenolides. While reviewing both the mechanisms and evolutionary ecology of cardenolide-mediated interactions, we advance novel hypotheses and suggest directions for future work.
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Affiliation(s)
- Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, and Department of Entomology, Cornell University, Ithaca, NY 14853, USA
| | - Georg Petschenka
- Biozentrum Grindel, Molekulare Evolutionsbiologie, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Robin A Bingham
- Department of Natural and Environmental Sciences, Western State College of Colorado, Gunnison, CO 81231, USA
| | - Marjorie G Weber
- Department of Ecology and Evolutionary Biology, and Department of Entomology, Cornell University, Ithaca, NY 14853, USA
| | - Sergio Rasmann
- Department of Ecology and Evolution, Bâtiment Biophore, University of Lausanne, CH - 1015 Lausanne, Switzerland
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Fordyce JA, Nice CC. Antagonistic, stage-specific selection on defensive chemical sequestration in a toxic butterfly. Evolution 2008; 62:1610-1617. [PMID: 18373625 DOI: 10.1111/j.1558-5646.2008.00388.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Larvae of the pipevine swallowtail (Battus philenor) sequester toxic alkaloids called aristolochic acids from their Aristolochia host plants, rendering both larvae and adults chemically defended against most predators. Using a chemically controlled artificial diet, we observed substantial among-family variation in sequestration ability and larval developmental rate in a population occurring in central Texas. Early instar larvae from families that sequester greater amounts of aristolochic acid showed increased survivorship in a field experiment in which cohorts from each family were exposed to natural predators, whereas among-family variation in growth rate did not predict survivorship. Conversely, the aristolochic acid content of adult butterflies was negatively correlated with adult fat content, a fitness correlate. Sequestration ability positively affects the probability of larval survivorship, but at the cost of adult fat content. The costs and benefits of aristolochic acid sequestration vary during the course of the butterfly's development, and these antagonistic selection pressures may explain why variation in sequestration ability persists in wild populations.
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Affiliation(s)
- James A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996, USA.
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MALCOLM S, ROTHSCHILD M. A danaid mullerian mimic, Euploea core amymone (Cramer) lacking cardenolides in the pupal and adult stages. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.1983.tb00774.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Farrell BD, Mitter C. The timing of insect/plant diversification: might Tetraopes (Coleoptera: Cerambycidae) and Asclepias (Asclepiadaceae) have co-evolved? Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.1998.tb00329.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zehnder CB, Hunter MD. Interspecific variation within the genus Asclepias in response to herbivory by a phloem-feeding insect herbivore. J Chem Ecol 2007; 33:2044-53. [PMID: 17929096 DOI: 10.1007/s10886-007-9364-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2007] [Revised: 08/16/2007] [Accepted: 08/31/2007] [Indexed: 11/25/2022]
Abstract
Induced plant responses to leaf-chewing insects have been well studied, but considerably less is known about the effects of phloem-feedings insects on induction. In a set of laboratory experiments, we examined density-dependent induction by the milkweed-oleander aphid, Aphis nerii, of putative defenses in four milkweed species (Asclepias incarnata, Asclepias syriaca, Asclepias tuberosa, and Asclepias viridis). We hypothesized that high aphid density would lead to increased cardenolide expression in species with low constitutive levels of cardenolides (e.g., A. tuberosa), but that there would be no induction in high constitutive cardenolide species (e.g., A. viridis). Based on previous studies, we did not expect cardenolide induction in A. incarnata. Contrary to our predictions, we observed feeding-induced declines of cardenolide concentrations in A. viridis. Cardenolide concentrations did not respond to aphid feeding in the other three milkweed species. Aphids also caused reductions in biomass accumulation by two of four Asclepias species, A. viridis and A. incarnata. High aphid density led to a decrease in A. viridis foliar nitrogen concentration. However, aphids had no effect on the defensive chemistry, growth, or nutritional quality of either A. syriaca or A. tuberosa. Our results highlight that congeneric plant species may respond differently to the same levels of herbivore damage.
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Affiliation(s)
- Caralyn B Zehnder
- Institute of Ecology, University of Georgia, Athens, GA, 30602, USA.
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Agrawal AA. Macroevolution of plant defense strategies. Trends Ecol Evol 2007; 22:103-9. [PMID: 17097760 DOI: 10.1016/j.tree.2006.10.012] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Revised: 09/28/2006] [Accepted: 10/30/2006] [Indexed: 11/12/2022]
Abstract
Theories of plant defense expression are typically based on the concepts of tradeoffs among traits and of phylogenetic conservatism within clades. Here, I review recent developments in phylogenetic approaches to understanding the evolution of plant defense strategies and plant-herbivore coevolutionary interactions. I focus particularly on multivariate defense against insect herbivores, which is the simultaneous deployment of multiple traits, often arranged as convergently evolved defense syndromes. Answering many of the outstanding questions in the biology of plant defense will require generating broad hypotheses that can be explicitly tested by using comparative approaches and interpreting phylogenetic patterns. The comparative approach has wide-spread potential to reinvigorate tests of classic hypotheses about the evolution of interspecific interactions.
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Affiliation(s)
- Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853-2701, USA.
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Fordyce JA, Marion ZH, Shapiro AM. Phenological Variation in Chemical Defense of the Pipevine Swallowtail, Battus philenor. J Chem Ecol 2005; 31:2835-46. [PMID: 16365708 DOI: 10.1007/s10886-005-8397-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 08/12/2005] [Accepted: 09/02/2005] [Indexed: 11/26/2022]
Abstract
Larvae of the pipevine swallowtail, Battus philenor, feed on plants in the genus Aristolochia, which contains aristolochic acids, toxic alkaloids unique to the Aristolochiaceae. Pipevine swallowtails sequester these compounds and, as a consequence, are chemically defended against many natural enemies. In California, the primary aristolochic acid present in the butterfly is aristolochic acid I. Newly eclosed adult females possess greater amounts of these sequestered toxins compared to males. However, over the course of the flight season, the aristolochic acid content of females in the population declines, whereas male aristolochic acid content remains relatively constant. Transference of sequestered aristolochic acids to eggs by females might explain the decline of these sequestered chemical defenses observed over time. We found no evidence that males transfer aristolochic acids to females via the spermatophore. The possibility that females at the end of the flight season may be automimics of males is discussed. Temporal variation in the aristolochic acid defenses exhibited by this pipevine swallowtail population is both age- and sex-dependent.
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Affiliation(s)
- James A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA.
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Morsy N, Matsuoka S, Houdai T, Matsumori N, Adachi S, Murata M, Iwashita T, Fujita T. Isolation and structure elucidation of a new amphidinol with a truncated polyhydroxyl chain from Amphidinium klebsii. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.07.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zalucki MP, Malcolm SB, Paine TD, Hanlon CC, Brower LP, Clarke AR. It’s the first bites that count: Survival of first-instar monarchs on milkweeds. AUSTRAL ECOL 2001. [DOI: 10.1046/j.1442-9993.2001.01132.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Farrell BD. Evolutionary assembly of the milkweed fauna: cytochrome oxidase I and the age of Tetraopes beetles. Mol Phylogenet Evol 2001; 18:467-78. [PMID: 11277638 DOI: 10.1006/mpev.2000.0888] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The insects that feed on the related plant families Apocynaceae and Asclepiadaceae (here collectively termed "milkweeds") comprise a "component community" of highly specialized, distinctive lineages of species that frequently sequester toxic cardiac glycosides from their host plants for defense against predators and are thus often aposematic, advertising their consequent unpalatability. Such sets of specialized lineages provide opportunities for comparative studies of the rate of adaptation, diversification, and habitat-related effects on molecular evolution. The cerambycid genus Tetraopes is the most diverse of the new world milkweed herbivores and the species are generally host specific, being restricted to single, different species of Asclepias, more often so than most other milkweed insects. Previous work revealed correspondence between the phylogeny of these beetles and that of their hosts. The present study provides analyses of near-complete DNA sequences for Tetraopes and relatives that are used to establish a molecular clock and temporal framework for Tetraopes evolution with their milkweed hosts.
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Affiliation(s)
- B D Farrell
- Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138, USA
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40
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Effect of hostplant genotype and predators on iridoid glycoside content of pupae of a specialist insect herbivore, Junonia coenia (Nymphalidae). BIOCHEM SYST ECOL 1997. [DOI: 10.1016/s0305-1978(97)00058-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Hunter MD, Malcolm SB, Hartley SE. Population-level variation in plant secondary chemistry, and the population biology of herbivores. CHEMOECOLOGY 1996. [DOI: 10.1007/bf01240637] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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42
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Malcolm SB. Milkweeds, monarch butterflies and the ecological significance of cardenolides. CHEMOECOLOGY 1994. [DOI: 10.1007/bf01240595] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Huang X, Renwick JAA. Cardenolides as oviposition deterrents to twoPieris species: Structure-activity relationships. J Chem Ecol 1994; 20:1039-51. [DOI: 10.1007/bf02059740] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/1993] [Accepted: 12/27/1993] [Indexed: 10/25/2022]
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44
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Leaf variation in iridoid glycoside content ofPlantago lanceolata (Plantaginaceae) and oviposition of the buckeye,Junonia coenia (Nymphalidae). CHEMOECOLOGY 1993. [DOI: 10.1007/bf01241676] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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45
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Effects of genotype, habitat, and seasonal variation on iridoid glycoside content of Plantago lanceolata (Plantaginaceae) and the implications for insect herbivores. Oecologia 1992; 91:201-207. [DOI: 10.1007/bf00317784] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/1991] [Accepted: 03/23/1992] [Indexed: 10/26/2022]
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46
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Zalucki MP, Brower LP. Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae). CHEMOECOLOGY 1992. [DOI: 10.1007/bf01245886] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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47
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Martin RA, Lynch SP, Brower LP, Malcolm SB, Van Hook T. Cardenolide content, emetic potency, and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus, and their larval host-plant milkweed,Asclepias humistrata, in Florida. CHEMOECOLOGY 1992. [DOI: 10.1007/bf01261450] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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48
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Farrell BD, Mitter C, Futuyma DJ. Diversification at the Insect-Plant Interface. Bioscience 1992. [DOI: 10.2307/1311626] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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49
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Phylogenetic studies of insect-plant interactions: Insights into the genesis of diversity. Trends Ecol Evol 1991; 6:290-3. [DOI: 10.1016/0169-5347(91)90007-k] [Citation(s) in RCA: 180] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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Groeneveld HW, Steijl H, Van Den Berg B, Elings JC. Rapid, quantitative HPLC analysis ofAsclepias fruticosa L. andDanaus plexippus L. cardenolides. J Chem Ecol 1990; 16:3373-82. [DOI: 10.1007/bf00982104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/1990] [Accepted: 06/28/1990] [Indexed: 10/25/2022]
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