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Zhang J, Cong Q, Shen J, Song L, Hallwachs W, Janzen DH, Sourakov A, Grishin NV. What one genus of showy moths can say about migration, adaptation, and wing pattern. Proc Natl Acad Sci U S A 2024; 121:e2319726121. [PMID: 38630713 PMCID: PMC11047066 DOI: 10.1073/pnas.2319726121] [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: 11/09/2023] [Accepted: 03/15/2024] [Indexed: 04/19/2024] Open
Abstract
The Ornate Moth, Utetheisa ornatrix, has served as a model species in chemical ecology studies for decades. Like in the widely publicized stories of the Monarch and other milkweed butterflies, the Ornate Moth and its relatives are tropical insects colonizing whole continents assisted by their chemical defenses. With the recent advances in genomic techniques and evo-devo research, it is becoming a model for studies in other areas, from wing pattern development to phylogeography, from toxicology to epigenetics. We used a genomic approach to learn about Utetheisa's evolution, detoxification, dispersal abilities, and wing pattern diversity. We present an evolutionary genomic analysis of the worldwide genus Utetheisa, then focusing on U. ornatrix. Our reference genome of U. ornatrix reveals gene duplications in the regions possibly associated with detoxification abilities, which allows them to feed on toxic food plants. Finally, comparative genomic analysis of over 100 U. ornatrix specimens from the museum with apparent differences in wing patterns suggest the potential roles of cortex and lim3 genes in wing pattern formation of Lepidoptera and the utility of museum-preserved collection specimens for wing pattern research.
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Affiliation(s)
- Jing Zhang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Qian Cong
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Jinhui Shen
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Leina Song
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - Winnie Hallwachs
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
| | - Daniel H. Janzen
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
| | - Andrei Sourakov
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL32611
| | - Nick V. Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390
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2
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Alvarez-Buylla A, Fischer MT, Moya Garzon MD, Rangel AE, Tapia EE, Tanzo JT, Soh HT, Coloma LA, Long JZ, O'Connell LA. Binding and sequestration of poison frog alkaloids by a plasma globulin. eLife 2023; 12:e85096. [PMID: 38206862 PMCID: PMC10783871 DOI: 10.7554/elife.85096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 12/07/2023] [Indexed: 01/13/2024] Open
Abstract
Alkaloids are important bioactive molecules throughout the natural world, and in many animals they serve as a source of chemical defense against predation. Dendrobatid poison frogs bioaccumulate alkaloids from their diet to make themselves toxic or unpalatable to predators. Despite the proposed roles of plasma proteins as mediators of alkaloid trafficking and bioavailability, the responsible proteins have not been identified. We use chemical approaches to show that a ~50 kDa plasma protein is the principal alkaloid-binding molecule in blood of poison frogs. Proteomic and biochemical studies establish this plasma protein to be a liver-derived alkaloid-binding globulin (ABG) that is a member of the serine-protease inhibitor (serpin) family. In addition to alkaloid-binding activity, ABG sequesters and regulates the bioavailability of 'free' plasma alkaloids in vitro. Unexpectedly, ABG is not related to saxiphilin, albumin, or other known vitamin carriers, but instead exhibits sequence and structural homology to mammalian hormone carriers and amphibian biliverdin-binding proteins. ABG represents a new small molecule binding functionality in serpin proteins, a novel mechanism of plasma alkaloid transport in poison frogs, and more broadly points toward serpins acting as tunable scaffolds for small molecule binding and transport across different organisms.
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Affiliation(s)
| | | | - Maria Dolores Moya Garzon
- Sarafan ChEM-H, Stanford UniversityStanfordUnited States
- Wu Tsai Institute for Neuroscience, Stanford UniversityStanfordUnited States
- Department of Pathology, Stanford UniversityStanfordUnited States
| | - Alexandra E Rangel
- Wu Tsai Human Performance Alliance, Stanford UniversityStanfordUnited States
| | - Elicio E Tapia
- Department of Radiology, Stanford UniversityStanfordUnited States
| | - Julia T Tanzo
- Sarafan ChEM-H, Stanford UniversityStanfordUnited States
- Wu Tsai Institute for Neuroscience, Stanford UniversityStanfordUnited States
| | - H Tom Soh
- Wu Tsai Human Performance Alliance, Stanford UniversityStanfordUnited States
- Center for Taxonomy and Morphology, Leibniz Institute for the Analysis of Biodiversity ChangeHamburgGermany
- Department of Electrical Engineering, Stanford UniversityStanfordUnited States
| | | | - Jonathan Z Long
- Sarafan ChEM-H, Stanford UniversityStanfordUnited States
- Wu Tsai Institute for Neuroscience, Stanford UniversityStanfordUnited States
- Department of Pathology, Stanford UniversityStanfordUnited States
- Centro Jambatu de Investigación y Conservación de Anfibios, Fundación JambatuSan RafaelEcuador
| | - Lauren A O'Connell
- Department of Biology, Stanford UniversityStanfordUnited States
- Wu Tsai Institute for Neuroscience, Stanford UniversityStanfordUnited States
- Stanford Diabetes Research Center, Stanford UniversityStanfordUnited States
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3
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Espinosa Del Alba L, Petschenka G. No physiological costs of dual sequestration of chemically different plant toxins in the milkweed bug Spilostethus saxatilis (Heteroptera: Lygaeidae). JOURNAL OF INSECT PHYSIOLOGY 2023; 147:104508. [PMID: 37011856 DOI: 10.1016/j.jinsphys.2023.104508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/06/2023] [Accepted: 03/31/2023] [Indexed: 06/02/2023]
Abstract
Many herbivorous insects not only cope with plant toxins but also sequester them as a defense against predators and parasitoids. Sequestration is a product of the evolutionary arms race between plants and herbivorous insects and has been hypothesized to incur physiological costs due to specific adaptations required. Contradictory evidence about these costs exists for insects sequestering only one class of toxin, but very little is known about the physiological implications for species sequestering structurally different classes of compounds. Spilostethus saxatilis is a milkweed bug belonging to the cardenolide-sequestering heteropteran subfamily Lygaeinae (Heteroptera: Lygaeidae) that has shifted to the colchicine-containing plant Colchicum autumnale, a resource of chemically unrelated alkaloids. Using feeding-assays on artificial diet and chemical analysis, we assessed whether S. saxatilis is still able to sequester cardenolides apart from colchicine and related metabolites (colchicoids), and tested the effect of (1) either a natural cardenolide concentration (using ouabain as a model compound) or a natural colchicine concentration, (2) an increased concentration of both toxins, and (3) seeds of either Asclepias syriaca (cardenolides) or C. autumnale (colchicoids) on a set of life-history traits. For comparison, we assessed the same life-history traits in the milkweed bug Oncopeltus fasciatus exposed to cardenolides only. Although cardenolides and colchicoids have different physiological targets (Na+/K+-ATPase vs tubulin) and thus require different resistance traits, chronic exposure and sequestration of both isolated toxins caused no physiological costs such as reduced growth, increased mortality, lower fertility, or shorter adult life span in S. saxatilis. Indeed, an increased performance was observed in O. fasciatus and an according trend was found in S. saxatilis when feeding on isolated ouabain and isolated colchicine, respectively. Positive effects were even more pronounced when insects were provided with natural toxic seeds (i.e. C. autumnale for S. saxatilis and A. syriaca for O. fasciatus), especially in O. fasciatus. Our findings suggest, that S. saxatilis can sequester two chemically unrelated classes of plant compounds at a cost-free level, and that colchicoids may even play a beneficial role in terms of fertility.
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Affiliation(s)
- Laura Espinosa Del Alba
- Department of Applied Entomology, Institute of Phytomedicine, University of Hohenheim, Otto-Sander Straße 5, 70599 Stuttgart, Germany
| | - Georg Petschenka
- Department of Applied Entomology, Institute of Phytomedicine, University of Hohenheim, Otto-Sander Straße 5, 70599 Stuttgart, Germany.
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Fontanilla AM, Aubona G, Sisol M, Kuukkanen I, Salminen JP, Miller SE, Holloway JD, Novotny V, Volf M, Segar ST. What Goes in Must Come Out? The Metabolic Profile of Plants and Caterpillars, Frass, And Adults of Asota (Erebidae: Aganainae) Feeding on Ficus (Moraceae) in New Guinea. J Chem Ecol 2022; 48:718-729. [PMID: 35972714 DOI: 10.1007/s10886-022-01379-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/01/2022] [Accepted: 08/05/2022] [Indexed: 11/26/2022]
Abstract
Insect herbivores have evolved a broad spectrum of adaptations in response to the diversity of chemical defences employed by plants. Here we focus on two species of New Guinean Asota and determine how these specialist moths deal with the leaf alkaloids of their fig (Ficus) hosts. As each focal Asota species is restricted to one of three chemically distinct species of Ficus, we also test whether these specialized interactions lead to similar alkaloid profiles in both Asota species. We reared Asota caterpillars on their respective Ficus hosts in natural conditions and analyzed the alkaloid profiles of leaf, frass, caterpillar, and adult moth samples using UHPLC-MS/MS analyses. We identified 43 alkaloids in our samples. Leaf alkaloids showed various fates. Some were excreted in frass or found in caterpillars and adult moths. We also found two apparently novel indole alkaloids-likely synthesized de novo by the moths or their microbiota-in both caterpillar and adult tissue but not in leaves or frass. Overall, alkaloids unique or largely restricted to insect tissue were shared across moth species despite feeding on different hosts. This indicates that a limited number of plant compounds have a direct ecological function that is conserved among the studied species. Our results provide evidence for the importance of phytochemistry and metabolic strategies in the formation of plant-insect interactions and food webs in general. Furthermore, we provide a new potential example of insects acquiring chemicals for their benefit in an ecologically relevant insect genus.
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Affiliation(s)
- Alyssa M Fontanilla
- Biology Centre, Institute of Entomology, the Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Gibson Aubona
- New Guinea Binatang Research Center, Madang, Papua New Guinea
| | - Mentap Sisol
- New Guinea Binatang Research Center, Madang, Papua New Guinea
| | - Ilari Kuukkanen
- Natural Chemistry Research Group, Department of Chemistry, University of Turku, Turku, Finland
| | - Juha-Pekka Salminen
- Natural Chemistry Research Group, Department of Chemistry, University of Turku, Turku, Finland
| | - Scott E Miller
- National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | | | - Vojtech Novotny
- Biology Centre, Institute of Entomology, the Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Martin Volf
- Biology Centre, Institute of Entomology, the Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Simon T Segar
- Agriculture and Environment Department, Harper Adams University, Newport, UK.
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Mattila ALK, Jiggins CD, Saastamoinen M. Condition dependence in biosynthesized chemical defenses of an aposematic and mimetic
Heliconius
butterfly. Ecol Evol 2022; 12:e9041. [PMID: 35784031 PMCID: PMC9227709 DOI: 10.1002/ece3.9041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/20/2022] [Accepted: 05/27/2022] [Indexed: 11/08/2022] Open
Abstract
Aposematic animals advertise their toxicity or unpalatability with bright warning coloration. However, acquiring and maintaining chemical defenses can be energetically costly, and consequent associations with other important traits could shape chemical defense evolution. Here, we have tested whether chemical defenses are involved in energetic trade‐offs with other traits, or whether the levels of chemical defenses are condition dependent, by studying associations between biosynthesized cyanogenic toxicity and a suite of key life‐history and fitness traits in a Heliconius butterfly under a controlled laboratory setting. Heliconius butterflies are well known for the diversity of their warning color patterns and widespread mimicry and can both sequester the cyanogenic glucosides of their Passiflora host plants and biosynthesize these toxins de novo. We find energetically costly life‐history traits to be either unassociated or to show a general positive association with biosynthesized cyanogenic toxicity. More toxic individuals developed faster and had higher mass as adults and a tendency for increased lifespan and fecundity. These results thus indicate that toxicity level of adult butterflies may be dependent on individual condition, influenced by genetic background or earlier conditions, with maternal effects as one strong candidate mechanism. Additionally, toxicity was higher in older individuals, consistent with previous studies indicating accumulation of toxins with age. As toxicity level at death was independent of lifespan, cyanogenic glucoside compounds may have been recycled to release resources relevant for longevity in these long‐living butterflies. Understanding the origins and maintenance of variation in defenses is necessary in building a more complete picture of factors shaping the evolution of aposematic and mimetic systems.
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Affiliation(s)
- Anniina L. K. Mattila
- Research Centre for Ecological Change, Organismal and Evolutionary Biology Research Programme University of Helsinki Helsinki Finland
- HiLIFE – Helsinki Institute of Life Science University of Helsinki Helsinki Finland
- Finnish Museum of Natural History (LUOMUS) University of Helsinki Helsinki Finland
| | | | - Marjo Saastamoinen
- Research Centre for Ecological Change, Organismal and Evolutionary Biology Research Programme University of Helsinki Helsinki Finland
- HiLIFE – Helsinki Institute of Life Science University of Helsinki Helsinki Finland
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6
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Pareja M, Rezende L. Direct and indirect plant defenses reduce damage by a generalist but not by a specialist pod borer. Biotropica 2022. [DOI: 10.1111/btp.13128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Martín Pareja
- Departamento de Biologia Animal, Instituto de Biologia Universidade Estadual de Campinas –UNICAMP Campinas Brazil
| | - Luiz Rezende
- Programa de Pós‐Graduação em Ecologia, Instituto de Biologia Universidade Estadual de Campinas –UNICAMP Campinas Brazil
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7
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Prada F, Stashenko EE, Martínez JR. Volatiles Emission by Crotalaria nitens after Insect Attack. Molecules 2021; 26:6941. [PMID: 34834034 PMCID: PMC8618423 DOI: 10.3390/molecules26226941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 01/09/2023] Open
Abstract
Plants are known to increase the emission of volatile organic compounds upon the damage of phytophagous insects. However, very little is known about the composition and temporal dynamics of volatiles released by wild plants of the genus Crotalaria (Fabaceae) attacked with the specialist lepidopteran caterpillar Utetheisa ornatrix (Linnaeus) (Erebidae). In this work, the herbivore-induced plant volatiles (HIPV) emitted by Crotalaria nitens Kunth plants were isolated with solid phase micro-extraction and the conventional purge and trap technique, and their identification was carried out by GC/MS. The poly-dimethylsiloxane/divinylbenzene fiber showed higher affinity for the extraction of apolar compounds (e.g., trans-β-caryophyllene) compared to the Porapak™-Q adsorbent from the purge & trap method that extracted more polar compounds (e.g., trans-nerolidol and indole). The compounds emitted by C. nitens were mainly green leaf volatile substances, terpenoids, aromatics, and aldoximes (isobutyraldoxime and 2-methylbutyraldoxime), whose maximum emission was six hours after the attack. The attack by caterpillars significantly increased the volatile compounds emission in the C. nitens leaves compared to those subjected to mechanical damage. This result indicated that the U. ornatrix caterpillar is responsible for generating a specific response in C. nitens plants. It was demonstrated that HIPVs repelled conspecific moths from attacked plants and favored oviposition in those without damage. The results showed the importance of volatiles in plant-insect interactions, as well as the choice of appropriate extraction and analytical methods for their study.
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Affiliation(s)
- Fausto Prada
- Center for Chromatography and Mass Spectrometry (CROM-MASS), Universidad Industrial de Santander, Bucaramanga 680002, Colombia; (F.P.); (J.R.M.)
- Colombia Research Center for Biomolecules (CIBIMOL), Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - Elena E. Stashenko
- Center for Chromatography and Mass Spectrometry (CROM-MASS), Universidad Industrial de Santander, Bucaramanga 680002, Colombia; (F.P.); (J.R.M.)
- Colombia Research Center for Biomolecules (CIBIMOL), Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - Jairo René Martínez
- Center for Chromatography and Mass Spectrometry (CROM-MASS), Universidad Industrial de Santander, Bucaramanga 680002, Colombia; (F.P.); (J.R.M.)
- Colombia Research Center for Biomolecules (CIBIMOL), Universidad Industrial de Santander, Bucaramanga 680002, Colombia
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8
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Seasonal Variation in Host Plant Chemistry Drives Sequestration in a Specialist Caterpillar. J Chem Ecol 2021; 48:79-88. [PMID: 34738204 DOI: 10.1007/s10886-021-01321-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/30/2021] [Accepted: 10/10/2021] [Indexed: 10/19/2022]
Abstract
Sequestration of plant secondary metabolites by herbivores can vary across both host plant phenology and herbivore ontogeny, but few studies have explored how they concurrently change in the field. We explored variation in iridoid glycoside concentration and composition in white turtlehead, Chelone glabra, as well as sequestration of iridoid glycosides by its specialist herbivore, the Baltimore checkerspot, Euphydryas phaeton, across the development of both herbivore and host plant. In 2012 we sampled plants to describe seasonal variation in the concentrations of two iridoid glycosides, aucubin and catalpol. In 2017, we sampled both host plants and caterpillars over an entire growing season and explored the relationship between plant chemistry and herbivore sequestration. We also compared iridoid glycoside concentrations of plants with and without herbivory to gain insight into whether levels of secondary compounds were impacted by herbivory. We found that total plant iridoid glycosides varied across the season and that total sequestered iridoid glycosides in caterpillars closely mirrored concentration patterns in plants. However, the magnitude of sequestration by caterpillars ranged from 2 to 20 times the concentrations in host plants, with different proportions of aucubin and catalpol. In addition, plants with herbivory had lower iridoid glycoside concentrations than plants without herbivory, although this difference changed over time. These results suggest that while variation in host plant secondary metabolites may be a dominant factor driving sequestration, other ecological factors may mitigate the relationship between host plant chemistry and herbivore sequestration.
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Silva-Brandão KL, Freitas AVL, Cardoso MZ, Cogni R, de Morais ABB. The Chemistry and Chemical Ecology of Lepidopterans as Investigated in Brazil. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2021; 116:37-66. [PMID: 34698945 DOI: 10.1007/978-3-030-80560-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The interdisciplinary field of Chemical Ecology in Brazil is currently composed of groups that emerged through the pioneering studies of Keith Spalding Brown Jr. and José Tércio Barbosa Ferreira. Following Keith Brown 's steps, José Roberto Trigo continued investigating the role of plant natural products in mediating the association among insects and their host plants, mainly in the Order Lepidoptera. The role of pyrrolizidine alkaloids in those associations was investigated extensively by Brown and Trigo, and most of what is currently known on this subject is based on their studies. The present work acknowledges their contribution to the Brazilian chemical ecology field and on insect-plant communication studies mediated by different chemical compounds.
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Affiliation(s)
- Karina L Silva-Brandão
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Av. Candido Rondom, 400, Campinas, SP, Brazil.
| | - André V L Freitas
- Departamento de Biologia Animal and Museu da Diversidade Biológica, Instituto de Biologia, Universidade Estadual de Campinas, Rua Monteiro Lobato, 255, Campinas, SP, Brazil
| | - Márcio Zikán Cardoso
- Departamento de Ecologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Rodrigo Cogni
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 321, São Paulo, SP, CEP 05508-090, Brazil
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10
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The geographical and seasonal mosaic in a plant-herbivore interaction: patterns of defences and herbivory by a specialist and a non-specialist. Sci Rep 2019; 9:15206. [PMID: 31645656 PMCID: PMC6811555 DOI: 10.1038/s41598-019-51528-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/24/2019] [Indexed: 12/01/2022] Open
Abstract
In order to evaluate the geographic mosaic theory of coevolution, it is crucial to investigate geographical variation on the outcome of ecological interactions and the functional traits which dictate these outcomes. Plant populations are attacked by specialist and non-specialist herbivores and may have different types of chemical and biotic defences. We investigated geographical and seasonal variation in the interaction between the plant Crotalaria pallida and its two major herbivores (the specialist Utetheisa ornatrix and the non-specialist Etiella zinckenella). We first showed that attack by the two herbivores and a chemical and a biotic defence vary greatly in time and space. Second, we performed a common garden experiment that revealed genetic variation among populations in herbivore resistance and a chemical defence, but no genetic variation in a biotic defence. Third, we sampled 20 populations on a much larger geographical scale and showed great variation in attack rates by the two herbivores and a chemical defence. Finally, we showed that herbivory is not correlated with a chemical defence in the 20 field populations. Our study shows that to understand the evolution of ecological interactions it is crucial to investigate how the outcome of the interaction and the important species traits vary geographically and seasonally.
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11
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Quinolizidine and Pyrrolizidine Alkaloid Chemical Ecology – a Mini-Review on Their Similarities and Differences. J Chem Ecol 2018; 45:109-115. [DOI: 10.1007/s10886-018-1005-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 07/13/2018] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
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12
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Züst T, Mou S, Agrawal AA. What doesn’t kill you makes you stronger: The burdens and benefits of toxin sequestration in a milkweed aphid. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tobias Züst
- Institute of Plant Sciences University of Bern Bern Switzerland
| | - Sophie Mou
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York
| | - Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York
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13
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Wink M. Plant Secondary Metabolites Modulate Insect Behavior-Steps Toward Addiction? Front Physiol 2018; 9:364. [PMID: 29695974 PMCID: PMC5904355 DOI: 10.3389/fphys.2018.00364] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 03/26/2018] [Indexed: 12/11/2022] Open
Abstract
Plants produce a diversity of secondary metabolites (PSMs) that serve as defense compounds against herbivores and microorganisms. In addition, some PSMs attract animals for pollination and seed dispersal. In case of pollinating insects, PSMs with colors or terpenoids with fragrant odors attract pollinators in the first place, but when they arrive at a flower, they are rewarded with nectar, so that the pollinators do not feed on flowers. In order to be effective as defense chemicals, PSMs evolved as bioactive substances, that can interfere with a large number of molecular targets in cells, tissues and organs of animals or of microbes. The known functions of PSMs are summarized in this review. A number of PSMs evolved as agonists or antagonists of neuronal signal transduction. Many of these PSMs are alkaloids. Several of them share structural similarities to neurotransmitters. Evidence for neuroactive and psychoactive PSMs in animals will be reviewed. Some of the neuroactive PSMs can cause addiction in humans and other vertrebrates. Why should a defense compound be addictive and thus attract more herbivores? Some insects are food specialists that can feed on plants that are normally toxic to other herbivores. These specialists can tolerate the toxins and many are stored in the insect body as acquired defense chemicals against predators. A special case are pyrrolizidine alkaloids (PAs) that are neurotoxic and mutagenic in vertebrates. PAs are actively sequestered by moths of the family Arctiidae and a few other groups of arthropods. In arctiids, PAs are not only used for defense, but also serve as morphogens for the induction of male coremata and as precursors for male pheromones. Caterpillars even feed on filter paper impregnated with pure PAs (that modulate serotonin receptors in vertebrates and maybe even in insects) and thus show of behavior with has similarities to addiction in vertebrates. Not only PA specialists, but also many monophagous herbivores select their host plants according to chemical cues i.e., PSMs) and crave for plants with a particular PSMs, again a similarity to addiction in vertebrates.
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Affiliation(s)
- Michael Wink
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
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15
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Livshultz T, Kaltenegger E, Straub SCK, Weitemier K, Hirsch E, Koval K, Mema L, Liston A. Evolution of pyrrolizidine alkaloid biosynthesis in Apocynaceae: revisiting the defence de-escalation hypothesis. THE NEW PHYTOLOGIST 2018; 218:762-773. [PMID: 29479722 PMCID: PMC5873419 DOI: 10.1111/nph.15061] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/10/2018] [Indexed: 05/23/2023]
Abstract
Plants produce specialized metabolites for their defence. However, specialist herbivores adapt to these compounds and use them for their own benefit. Plants attacked predominantly by specialists may be under selection to reduce or eliminate production of co-opted chemicals: the defence de-escalation hypothesis. We studied the evolution of pyrrolizidine alkaloids (PAs) in Apocynaceae, larval host plants for PA-adapted butterflies (Danainae, milkweed and clearwing butterflies), to test if the evolutionary pattern is consistent with de-escalation. We used the first PA biosynthesis specific enzyme (homospermidine synthase, HSS) as tool for reconstructing PA evolution. We found hss orthologues in diverse Apocynaceae species, not all of them known to produce PAs. The phylogenetic analysis showed a monophyletic origin of the putative hss sequences early in the evolution of one Apocynaceae lineage (the APSA clade). We found an hss pseudogene in Asclepias syriaca, a species known to produce cardiac glycosides but no PAs, and four losses of an HSS amino acid motif. APSA clade species are significantly more likely to be Danainae larval host plants than expected if all Apocynaceae species were equally likely to be exploited. Our findings are consistent with PA de-escalation as an adaptive response to specialist attack.
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Affiliation(s)
- Tatyana Livshultz
- Department of Biodiversity, Earth, and Environmental SciencesAcademy of Natural Sciences of Drexel University1900 Benjamin Franklin ParkwayPhiladelphiaPA19103USA
| | - Elisabeth Kaltenegger
- Biochemical Ecology and Molecular EvolutionBotanical InstituteChristian‐Albrechts University KielOlshausenstrasse 4024098KielGermany
| | | | - Kevin Weitemier
- Department of Botany & Plant PathologyOregon State University2082 Cordley HallCorvallisOR97331USA
| | - Elliot Hirsch
- Department of Biodiversity, Earth, and Environmental SciencesAcademy of Natural Sciences of Drexel University1900 Benjamin Franklin ParkwayPhiladelphiaPA19103USA
| | - Khrystyna Koval
- Department of Biodiversity, Earth, and Environmental SciencesAcademy of Natural Sciences of Drexel University1900 Benjamin Franklin ParkwayPhiladelphiaPA19103USA
| | - Lumi Mema
- Department of Biodiversity, Earth, and Environmental SciencesAcademy of Natural Sciences of Drexel University1900 Benjamin Franklin ParkwayPhiladelphiaPA19103USA
| | - Aaron Liston
- Department of Botany & Plant PathologyOregon State University2082 Cordley HallCorvallisOR97331USA
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Birnbaum SSL, Rinker DC, Gerardo NM, Abbot P. Transcriptional profile and differential fitness in a specialist milkweed insect across host plants varying in toxicity. Mol Ecol 2017; 26:6742-6761. [PMID: 29110382 DOI: 10.1111/mec.14401] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/18/2017] [Indexed: 01/03/2023]
Abstract
Interactions between plants and herbivorous insects have been models for theories of specialization and co-evolution for over a century. Phytochemicals govern many aspects of these interactions and have fostered the evolution of adaptations by insects to tolerate or even specialize on plant defensive chemistry. While genomic approaches are providing new insights into the genes and mechanisms insect specialists employ to tolerate plant secondary metabolites, open questions remain about the evolution and conservation of insect counterdefences, how insects respond to the diversity defences mounted by their host plants, and the costs and benefits of resistance and tolerance to plant defences in natural ecological communities. Using a milkweed-specialist aphid (Aphis nerii) model, we test the effects of host plant species with increased toxicity, likely driven primarily by increased secondary metabolites, on aphid life history traits and whole-body gene expression. We show that more toxic plant species have a negative effect on aphid development and lifetime fecundity. When feeding on more toxic host plants with higher levels of secondary metabolites, aphids regulate a narrow, targeted set of genes, including those involved in canonical detoxification processes (e.g., cytochrome P450s, hydrolases, UDP-glucuronosyltransferases and ABC transporters). These results indicate that A. nerii marshal a variety of metabolic detoxification mechanisms to circumvent milkweed toxicity and facilitate host plant specialization, yet, despite these detoxification mechanisms, aphids experience reduced fitness when feeding on more toxic host plants. Disentangling how specialist insects respond to challenging host plants is a pivotal step in understanding the evolution of specialized diet breadths.
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Affiliation(s)
| | - David C Rinker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Nicole M Gerardo
- Department of Biology, O. Wayne Rollins Research Center, Emory University, Atlanta, GA, USA
| | - Patrick Abbot
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
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17
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Rojas B, Burdfield-Steel E, Pakkanen H, Suisto K, Maczka M, Schulz S, Mappes J. How to fight multiple enemies: target-specific chemical defences in an aposematic moth. Proc Biol Sci 2017; 284:20171424. [PMID: 28954910 PMCID: PMC5627206 DOI: 10.1098/rspb.2017.1424] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/25/2017] [Indexed: 11/12/2022] Open
Abstract
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from its thoracic glands and abdomen. We presented the two defensive fluids from laboratory-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive fluids are target-specific: thoracic fluids, and particularly 2-sec-butyl-3-methoxypyrazine, which they contain, deterred birds, but caused no aversive response in ants. By contrast, abdominal fluids were particularly deterrent to ants, while birds did not find them repellent. Our study, to our knowledge, is the first to show evidence of a single species producing separate chemical defences targeted to different predator types, highlighting the importance of taking into account complex predator communities in studies on the evolution of prey defence diversity.
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Affiliation(s)
- Bibiana Rojas
- Centre of Excellence in Biological Interactions, Department of Biology and Environmental Sciences, University of Jyväskylä, PO Box 35, Jyväskylä 40001, Finland
| | - Emily Burdfield-Steel
- Centre of Excellence in Biological Interactions, Department of Biology and Environmental Sciences, University of Jyväskylä, PO Box 35, Jyväskylä 40001, Finland
| | - Hannu Pakkanen
- Department of Chemistry, University of Jyväskylä, Survontie 9, Jyväskylä 40500, Finland
| | - Kaisa Suisto
- Centre of Excellence in Biological Interactions, Department of Biology and Environmental Sciences, University of Jyväskylä, PO Box 35, Jyväskylä 40001, Finland
| | - Michael Maczka
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany
| | - Stefan Schulz
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany
| | - Johanna Mappes
- Centre of Excellence in Biological Interactions, Department of Biology and Environmental Sciences, University of Jyväskylä, PO Box 35, Jyväskylä 40001, Finland
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18
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Andreazzi CS, Thompson JN, Guimarães PR. Network Structure and Selection Asymmetry Drive Coevolution in Species-Rich Antagonistic Interactions. Am Nat 2017; 190:99-115. [DOI: 10.1086/692110] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Localization of Defensive Chemicals in Two Congeneric Butterflies (Euphydryas, Nymphalidae). J Chem Ecol 2017; 43:480-486. [PMID: 28393296 DOI: 10.1007/s10886-017-0841-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 03/03/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
Many insect species sequester compounds acquired from their host plants for defense against natural enemies. The distribution of these compounds is likely to affect both their efficacy as defenses, and their costs. In this study we examined the distribution of sequestered iridoid glycosides (IGs) in two congeneric species of nymphalid butterfly, Euphydryas anicia and E. phaeton, and found that the pattern of localization of IGs differed between the two species. Although IG concentrations were quite high in the heads of both species, the relative concentrations in wings and abdomens differed substantially. Euphydryas anicia had relatively high IG concentrations in their abdomens and low IG concentrations in their wings, whereas the reverse was true in E. phaeton. We interpret these results in light of two current hypotheses regarding where sequestered chemicals should be localized: that they should be found in wings, which would allow non-lethal sampling by predators; and that their distribution is constrained by the distribution of tissue types to which sequestered compounds bind. We also offer the third hypothesis, that costs of storage may differ among body parts, and that the localization of compounds may reflect a cost-reduction strategy. Results from E. phaeton were consistent with all three of these non-mutually exclusive hypotheses, whereas results from E. anicia were only consistent with the notion that tissue bias among body parts plays a role in IG distribution. The finding that these two congeneric butterflies exhibit different patterns of IG localization suggests that they have been shaped by different selection regimes.
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20
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Weinstein BG, Graham CH. Persistent bill and corolla matching despite shifting temporal resources in tropical hummingbird-plant interactions. Ecol Lett 2017; 20:326-335. [PMID: 28150364 DOI: 10.1111/ele.12730] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/22/2016] [Accepted: 12/12/2016] [Indexed: 11/26/2022]
Abstract
By specialising on specific resources, species evolve advantageous morphologies to increase the efficiency of nutrient acquisition. However, many specialists face variation in resource availability and composition. Whether specialists respond to these changes depends on the composition of the resource pulses, the cost of foraging on poorly matched resources, and the strength of interspecific competition. We studied hummingbird bill and plant corolla matching during seasonal variation in flower availability and morphology. Using a hierarchical Bayesian model, we accounted for the detectability and spatial overlap of hummingbird-plant interactions. We found that despite seasonal pulses of flowers with short-corollas, hummingbirds consistently foraged on well-matched flowers, leading to low niche overlap. This behaviour suggests that the costs of searching for rare and more specialised resources are lower than the benefit of switching to super-abundant resources. Our results highlight the trade-off between foraging efficiency and interspecific competition, and underline niche partitioning in maintaining tropical diversity.
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Affiliation(s)
- Ben G Weinstein
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Catherine H Graham
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11794, USA
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21
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Zvereva EL, Zverev V, Kruglova OY, Kozlov MV. Strategies of chemical anti-predator defences in leaf beetles: is sequestration of plant toxins less costly than de novo synthesis? Oecologia 2016; 183:93-106. [PMID: 27718063 DOI: 10.1007/s00442-016-3743-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 09/27/2016] [Indexed: 11/28/2022]
Abstract
The evolution of defensive traits is driven both by benefits gained from protection against enemies and by costs of defence production. We tested the hypothesis that specialisation of herbivores on toxic host plants, accompanied by the ability to acquire plant defensive compounds for herbivore defence, is favoured by the lower costs of sequestration compared to de novo synthesis of defensive compounds. We measured physiological costs of chemical defence as a reduction in larval performance in response to repeated removal of secretions (simulating predator attack) and compared these costs between five species synthesising defences de novo and three species sequestering salicylic glucosides (SGs) from their host plants. Experiments simulating low predator pressure revealed no physiological costs in terms of survival, weight and duration of development in any of study species. However, simulation of high predation caused reduction in relative growth rate in Chrysomela lapponica larvae producing autogenous defences more frequently, than in larvae sequestering SGs. Still meta-analysis of combined data showed no overall difference in costs of autogenous and sequestered defences. However, larvae synthesising their defences de novo demonstrated secretion-conserving behaviour, produced smaller amounts of secretions, replenished them at considerably lower rates and employed other types of defences (regurgitation, evasion) more frequently when compared to sequestering larvae. These latter results provide indirect evidence for biosynthetic constraints for amounts of defensive secretions produced de novo, resulting in low defence effectiveness. Lifting these constraints by sequestration may have driven some leaf beetle lineages toward sequestration of plant allelochemicals as the main defensive strategy.
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Affiliation(s)
- Elena L Zvereva
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland.
| | - Vitali Zverev
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland
| | | | - Mikhail V Kozlov
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland
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22
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Cogni R, Trigo JR. Pyrrolizidine Alkaloids Negatively Affect a Generalist Herbivore Feeding on the Chemically Protected Legume Crotalaria pallida. NEOTROPICAL ENTOMOLOGY 2016; 45:252-7. [PMID: 26830432 DOI: 10.1007/s13744-016-0361-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 01/03/2016] [Indexed: 05/20/2023]
Abstract
Plant secondary metabolites can have opposing effects on adapted specialist and non-adapted, generalist herbivores. In this study, we used Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) as a generalist, non-adapted model herbivore to test the possible effects of Crotalaria pallida (Fabaceae: Papilionoideae) defenses on herbivore performance. Neonate H. virescens larvae were able to consume C. pallida leaves and fruits and grow for a few instars, but none of them survived to pupation. We added isolated pyrrolizidine alkaloids (PAs) to an artificial diet at different concentrations, and PA concentration significantly affected the number of larvae that achieved pupation. Larval survival was not reduced at a PA concentration similar to the concentration on green seeds of C. pallida, but it was significantly reduced at PA concentration 5 and 100 times higher. These results suggest that PAs in isolation are not the defense responsible for the mortality in fresh C. pallida plants, indicating the importance of other possible defenses. The negative effect of PAs on fitness of the non-adapted, generalist herbivore is in agreement with few previous studies, but it is in clear contrast to a previous study on the effects of PAs on the adapted specialist herbivore Utetheisa ornatrix (L.) that were able to sequester PAs with no fitness costs.
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Affiliation(s)
- R Cogni
- Departamento de Ecologia, Instituto de Biociências, Univ de São Paulo, São Paulo, Brasil.
| | - J R Trigo
- Depto de Biologia Animal, Instituto de Biologia, Univ Estadual de Campinas, Campinas, SP, Brasil
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Petschenka G, Agrawal AA. How herbivores coopt plant defenses: natural selection, specialization, and sequestration. CURRENT OPINION IN INSECT SCIENCE 2016; 14:17-24. [PMID: 27436642 DOI: 10.1016/j.cois.2015.12.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/10/2015] [Accepted: 12/20/2015] [Indexed: 05/10/2023]
Abstract
We review progress in understanding sequestration by herbivorous insects, the use of plant chemical defenses for their own defense. We incorporate sequestration into the framework of plant-insect coevolution by integrating three hierarchical issues: (1) the relationship between dietary specialization and sequestration of plant defenses, (2) the physiological mechanisms involved in sequestration, and (3) how sequestration evolves via interactions between trophic levels. Sequestration is often associated with specialization, but even specialized sequestration is not an evolutionary dead-end. Despite considerable progress in understanding physiological mechanisms, detailed knowledge of how plant toxins cross the insect gut epithelium is still largely lacking. Sequestration is likely a major vehicle for coevolutionary escalation in speciose plant-insect-predator interactions, suggesting that a strictly bitrophic view is untenable.
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Affiliation(s)
- Georg Petschenka
- Institut für Insektenbiotechnologie, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
| | - Anurag A Agrawal
- Ecology and Evolutionary Biology, Cornell University, E425 Corson Hall, Ithaca, NY 14853 USA
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Feeding on Host Plants with Different Concentrations and Structures of Pyrrolizidine Alkaloids Impacts the Chemical-Defense Effectiveness of a Specialist Herbivore. PLoS One 2015; 10:e0141480. [PMID: 26517873 PMCID: PMC4627748 DOI: 10.1371/journal.pone.0141480] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 10/08/2015] [Indexed: 11/19/2022] Open
Abstract
Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae) sequester N-oxides of pyrrolizidine alkaloids (PAs) from these host plants, and transfer them to adults through the pupal stage. PAs confer protection against predation on all life stages of U. ornatrix. As U. ornatrix also uses other Crotalaria species as host plants, we evaluated whether the PA chemical defense against predation is independent of host plant use. We fed larvae from hatching to pupation with either leaves or seeds of one of eight Crotalaria species (C. incana, C. juncea, C. micans, C. ochroleuca, C. pallida, C. paulina, C. spectabilis, and C. vitellina), and tested if adults were preyed upon or released by the orb-weaving spider Nephila clavipes. We found that the protection against the spider was more effective in adults whose larvae fed on seeds, which had a higher PA concentration than leaves. The exceptions were adults from larvae fed on C. paulina, C. spectabilis and C. vitellina leaves, which showed high PA concentrations. With respect to the PA profile, we describe for the first time insect-PAs in U. ornatrix. These PAs, biosynthesized from the necine base retronecine of plant origin, or monocrotaline- and senecionine-type PAs sequestered from host plants, were equally active in moth chemical defense, in a dose-dependent manner. These results are also partially explained by host plant phylogeny, since PAs of the host plants do have a phylogenetic signal (clades with high and low PA concentrations in leaves) which is reflected in the adult defense.
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New sources of lycopsamine-type pyrrolizidine alkaloids and their distribution in Apocynaceae. BIOCHEM SYST ECOL 2015. [DOI: 10.1016/j.bse.2015.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Sourakov A. You are what you eat: native versus exoticCrotalariaspecies (Fabaceae) as host plants of the Ornate Bella Moth,Utetheisa ornatrix(Lepidoptera: Erebidae: Arctiinae). J NAT HIST 2015. [DOI: 10.1080/00222933.2015.1006700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Intake and transformation to a glycoside of (Z)-3-hexenol from infested neighbors reveals a mode of plant odor reception and defense. Proc Natl Acad Sci U S A 2014; 111:7144-9. [PMID: 24778218 DOI: 10.1073/pnas.1320660111] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Plants receive volatile compounds emitted by neighboring plants that are infested by herbivores, and consequently the receiver plants begin to defend against forthcoming herbivory. However, to date, how plants receive volatiles and, consequently, how they fortify their defenses, is largely unknown. In this study, we found that undamaged tomato plants exposed to volatiles emitted by conspecifics infested with common cutworms (exposed plants) became more defensive against the larvae than those exposed to volatiles from uninfested conspecifics (control plants) in a constant airflow system under laboratory conditions. Comprehensive metabolite analyses showed that only the amount of (Z)-3-hexenylvicianoside (HexVic) was higher in exposed than control plants. This compound negatively affected the performance of common cutworms when added to an artificial diet. The aglycon of HexVic, (Z)-3-hexenol, was obtained from neighboring infested plants via the air. The amount of jasmonates (JAs) was not higher in exposed plants, and HexVic biosynthesis was independent of JA signaling. The use of (Z)-3-hexenol from neighboring damaged conspecifics for HexVic biosynthesis in exposed plants was also observed in an experimental field, indicating that (Z)-3-hexenol intake occurred even under fluctuating environmental conditions. Specific use of airborne (Z)-3-hexenol to form HexVic in undamaged tomato plants reveals a previously unidentified mechanism of plant defense.
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Franco MS, Cogni R. Common-garden experiments reveal geographical variation in the interaction among Crotalaria pallida (Leguminosae: Papilionideae), Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and extrafloral nectary visiting ants. NEOTROPICAL ENTOMOLOGY 2013; 42:223-229. [PMID: 23949803 DOI: 10.1007/s13744-013-0114-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 01/22/2013] [Indexed: 06/02/2023]
Abstract
The study of geographical variation is a key approach to understand evolution of ecological interactions. We investigated geographical variation in the interaction among Crotalaria pallida (Leguminosae: Papilionideae), its specialized herbivore, Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and ants attracted to extrafloral nectaries (EFNs). First, we used common-garden experiments with plants collected in different sites at different geographical scales to test for differences among populations in C. pallida attractiveness to ants. When we compared three populations from Southeast Brazil (150 km apart), the number of visiting ants per plant, and the percent of termite baits attacked by ants, were significantly different among plant populations. In a comparison of populations from SE Brazil and Florida (USA), there was no significant difference between the populations in the number of ants per plant or the frequency of baits attacked. Second, we tested in a common garden if U. ornatrix larvae present any behavior to avoid ant predation, and if there were genetic differences among populations. We observed that most larvae moved away from the vicinity of the EFNs (flowers and fruits) to the plant leaves. Of the larvae that moved to leaves, only 10% were attacked by ants while 89% of larvae that stayed near the fruit/flower were attacked. There was a significant difference among populations in the frequency of larvae that moved to the leaves and the frequency of larvae attacked by ants. We discuss the possible causes of the geographical differences observed and propose future research directions in this system.
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Affiliation(s)
- M S Franco
- Depto de Biologia Animal, Instituto de Biologia, Univ Estadual de Campinas, Campinas, SP, Brasil
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