1
|
Thon FM, Müller C, Wittmann MJ. The evolution of chemodiversity in plants-From verbal to quantitative models. Ecol Lett 2024; 27:e14365. [PMID: 38362774 DOI: 10.1111/ele.14365] [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: 07/10/2023] [Revised: 10/31/2023] [Accepted: 12/09/2023] [Indexed: 02/17/2024]
Abstract
Plants harbour a great chemodiversity, that is diversity of specialised metabolites (SMs), at different scales. For instance, individuals can produce a large number of SMs, and populations can differ in their metabolite composition. Given the ecological and economic importance of plant chemodiversity, it is important to understand how it arises and is maintained over evolutionary time. For other dimensions of biodiversity, that is species diversity and genetic diversity, quantitative models play an important role in addressing such questions. Here, we provide a synthesis of existing hypotheses and quantitative models, that is mathematical models and computer simulations, for the evolution of plant chemodiversity. We describe each model's ingredients, that is the biological processes that shape chemodiversity, the scales it considers and whether it has been formalized as a quantitative model. Although we identify several quantitative models, not all are dynamic and many influential models have remained verbal. To fill these gaps, we outline our vision for the future of chemodiversity modelling. We identify quantitative models used for genetic variation that may be adapted for chemodiversity, and we present a flexible framework for the creation of individual-based models that address different scales of chemodiversity and combine different ingredients that bring this chemodiversity about.
Collapse
Affiliation(s)
- Frans M Thon
- Faculty of Biology, Theoretical Biology, Bielefeld University, Bielefeld, Germany
| | - Caroline Müller
- Faculty of Biology, Chemical Ecology, Bielefeld University, Bielefeld, Germany
- Joint Institute for Individualisation in a Changing Environment (JICE), University of Münster and Bielefeld University, Bielefeld, Germany
| | - Meike J Wittmann
- Faculty of Biology, Theoretical Biology, Bielefeld University, Bielefeld, Germany
- Joint Institute for Individualisation in a Changing Environment (JICE), University of Münster and Bielefeld University, Bielefeld, Germany
| |
Collapse
|
2
|
Gelambi M, Whitehead SR. Multiscale variability in nutrients and secondary metabolites in a bat-dispersed neotropical fruit. Ecol Evol 2023; 13:e10453. [PMID: 37664504 PMCID: PMC10474796 DOI: 10.1002/ece3.10453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/31/2023] [Accepted: 08/15/2023] [Indexed: 09/05/2023] Open
Abstract
Ripe fleshy fruits contain not only nutrients but also a diverse array of secondary metabolites. Nutrients serve as a reward for mutualists, whereas defensive metabolites protect the fruit against pests and predators. The composition of these chemical traits is highly variable, both across different plants and even within repeating structures on the same individual plant. This intraspecific and intraindividual variation has important fitness consequences for both plants and animals, yet patterns of variation and covariation in nutrients and secondary metabolites are not well understood, especially at smaller scales. Here, we investigate the multiscale variation and covariation between nutrients and defensive metabolites in Piper sancti-felicis ripe fruits. Means and measures of variation of sugars, proteins, phenolics, and alkenylphenols vary greatly among plants, and at least 50% of the trait variation occurs at the intraindividual level. Also, we found that proteins, but not sugars, were correlated with phenolics and alkenylphenols at multiple scales, suggesting trait variation in protein content may be more constrained than sugars. Our findings emphasize the importance of examining patterns across scales and provide the groundwork to better understand how complex patterns of variation and covariation in nutrients and defensive metabolites shape ecological interactions surrounding fruits.
Collapse
Affiliation(s)
- Mariana Gelambi
- Department of Biological SciencesVirginia Polytechnic Institute and State UniversityBlacksburgVirginiaUSA
- La Selva Biological StationOrganization for Tropical StudiesPuerto Viejo de SarapiquíHeredia ProvinceCosta Rica
| | - Susan R. Whitehead
- Department of Biological SciencesVirginia Polytechnic Institute and State UniversityBlacksburgVirginiaUSA
- La Selva Biological StationOrganization for Tropical StudiesPuerto Viejo de SarapiquíHeredia ProvinceCosta Rica
| |
Collapse
|
3
|
The role of timing in intraspecific trait ecology. Trends Ecol Evol 2022; 37:997-1005. [DOI: 10.1016/j.tree.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 11/17/2022]
|
4
|
Hauri KC, Glassmire AE, Randall B, Zehr LN, Wetzel WC. Plant chemical diversity and its frequency have distinct but complementary effects on insect foraging. J Appl Ecol 2022. [DOI: 10.1111/1365-2664.14151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Kayleigh C. Hauri
- Department of Entomology Michigan State University East Lansing MI USA
- Ecology, Evolution, and Behavior Program Michigan State University East Lansing MI USA
| | - Andrea E. Glassmire
- Department of Entomology Michigan State University East Lansing MI USA
- Ecology, Evolution, and Behavior Program Michigan State University East Lansing MI USA
| | - Brendan Randall
- Department of Entomology Michigan State University East Lansing MI USA
| | - Luke N. Zehr
- Department of Entomology Michigan State University East Lansing MI USA
| | - William C. Wetzel
- Department of Entomology Michigan State University East Lansing MI USA
- Ecology, Evolution, and Behavior Program Michigan State University East Lansing MI USA
- Department of Integrative Biology Michigan State University East Lansing MI USA
- Kellogg Biological Station Michigan State University Hickory Corners MI USA
- AgBioResearch Michigan State University East Lansing MI USA
| |
Collapse
|
5
|
Jaccard C, Marguier NT, Arce CCM, Bruno P, Glauser G, Turlings TCJ, Benrey B. The effect of squash domestication on a belowground tritrophic interaction. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2022; 3:28-39. [PMID: 37283693 PMCID: PMC10168047 DOI: 10.1002/pei3.10071] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/31/2021] [Accepted: 01/13/2022] [Indexed: 06/08/2023]
Abstract
The domestication of plants has commonly resulted in the loss of plant defense metabolites, with important consequences for the plants' interactions with herbivores and their natural enemies. Squash domestication started 10'000 years ago and has led to the loss of cucurbitacins, which are highly toxic triterpenes. The banded cucumber beetle (Diabrotica balteata), a generalist herbivore, is adapted to feed on plants from the Cucurbitaceae and is known to sequester cucurbitacins, supposedly for its own defense. However, the evidence for this is inconclusive. In this study we tested the impact of squash domestication on the chemical protection of D. balteata larvae against a predatory rove beetle (Dalotia coriaria). We found that cucurbitacins do not defend the larvae against this common soil dwelling predator. In fact, D. balteata larvae were less attacked when they fed on cucurbitacin-free roots of domesticated varieties compared to high-cucurbitacin roots of wild plants. This study appears to be the first to look at the consequences of plant domestication on belowground tritrophic interactions. Our results challenge the generalized assumption that sequestered cucurbitacins protect this herbivore against natural enemies, and instead reveals an opposite effect that may be due to a tradeoff between coping with cucurbitacins and avoiding predation.
Collapse
Affiliation(s)
- Charlyne Jaccard
- Institute of Biology, Laboratory of Evolutionary EntomologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Nicolas T. Marguier
- Institute of Biology, Laboratory of Evolutionary EntomologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Carla C. M. Arce
- Laboratory of Fundamental and Applied Research in Chemical EcologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Pamela Bruno
- Laboratory of Fundamental and Applied Research in Chemical EcologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Gaëtan Glauser
- Neuchâtel Platform of Analytical ChemistryUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Ted C. J. Turlings
- Laboratory of Fundamental and Applied Research in Chemical EcologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Betty Benrey
- Institute of Biology, Laboratory of Evolutionary EntomologyUniversity of NeuchâtelNeuchâtelSwitzerland
| |
Collapse
|
6
|
Robinson ML, Schilmiller AL, Wetzel WC. A domestic plant differs from its wild relative along multiple axes of within-plant trait variability and diversity. Ecol Evol 2022; 12:e8545. [PMID: 35127045 PMCID: PMC8794722 DOI: 10.1002/ece3.8545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/28/2021] [Accepted: 12/22/2021] [Indexed: 11/08/2022] Open
Abstract
For 10,000 years humans have altered plant traits through domestication and ongoing crop improvement, shaping plant form and function in agroecosystems. To date, studies have focused on how these processes shape whole-plant or average traits; however, plants also have characteristic levels of trait variability among their repeated parts, which can be heritable and mediate critical ecological interactions. Here, we examine an underappreciated scale of trait variation-among leaves, within plants-that may have changed through the process of domestication and improvement. Variability at this scale may itself be a target of selection, or be shaped as a by-product of the domestication process. We explore how levels of among-leaf trait variability differ between cultivars and wild relatives of alfalfa (Medicago sativa), a key forage crop with a 7,000-year domestication history. We grew individual plants from 30 wild populations and 30 cultivars, and quantified variability in a broad suite of physical, nutritive, and chemical leaf traits, including measures of chemical dissimilarity (beta diversity) among leaves within each plant. We find that trait variability has changed over the course of domestication, with effects often larger than changes in trait means. Domestic alfalfa had elevated among-leaf variability in SLA, trichomes, and C:N; increased diversity in defensive compounds; and reduced variability in phytochemical composition. We also elucidate fundamental relationships between trait means and variability, and between overall production of secondary metabolites and patterns of chemical diversity. We conclude that within-plant variability is an overlooked dimension of trait diversity in a globally critical agricultural crop. Trait variability is actually higher in cultivated plants compared to wild progenitors for multiple nutritive, physical, and chemical traits, highlighting a scale of variation that may mitigate loss of trait diversity at other scales in alfalfa agroecosystems, and in other crops with similar histories of domestication and improvement.
Collapse
Affiliation(s)
- Moria L. Robinson
- Department of EntomologyMichigan State UniversityEast LansingMichiganUSA
- Kellogg Biological StationMichigan State UniversityEast LansingMichiganUSA
- Ecology, Evolution, and Behavior ProgramMichigan State UniversityEast LansingMichiganUSA
| | | | - William C. Wetzel
- Department of EntomologyMichigan State UniversityEast LansingMichiganUSA
- Kellogg Biological StationMichigan State UniversityEast LansingMichiganUSA
- Ecology, Evolution, and Behavior ProgramMichigan State UniversityEast LansingMichiganUSA
- Department of Integrative BiologyMichigan State UniversityEast LansingMichiganUSA
- AgBioResearchMichigan State UniversityEast LansingMichiganUSA
| |
Collapse
|
7
|
Grof-Tisza P, Karban R, Rasheed MU, Saunier A, Blande JD. Risk of herbivory negatively correlates with the diversity of volatile emissions involved in plant communication. Proc Biol Sci 2021; 288:20211790. [PMID: 34702072 PMCID: PMC8548805 DOI: 10.1098/rspb.2021.1790] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/06/2021] [Indexed: 11/12/2022] Open
Abstract
Plant-to-plant volatile-mediated communication and subsequent induced resistance to insect herbivores is common. Less clear is the adaptive significance of these interactions; what selective mechanisms favour plant communication and what conditions allow individuals to benefit by both emitting and responding to cues? We explored the predictions of two non-exclusive hypotheses to explain why plants might emit cues, the kin selection hypothesis (KSH) and the mutual benefit hypothesis (MBH). We examined 15 populations of sagebrush that experience a range of naturally occurring herbivory along a 300 km latitudinal transect. As predicted by the KSH, we found several uncommon chemotypes with some chemotypes occurring only within a single population. Consistent with the MBH, chemotypic diversity was negatively correlated with herbivore pressure; sites with higher levels of herbivory were associated with a few common cues broadly recognized by most individuals. These cues varied among different populations. Our results are similar to those reported for anti-predator signalling in vertebrates.
Collapse
Affiliation(s)
- Patrick Grof-Tisza
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, Kuopio 70211, Finland
| | - Richard Karban
- Department of Entomology and Nematology, University of California, 1 Shields Avenue, Davis, CA 95616, USA
| | - Muhammad Usman Rasheed
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, Kuopio 70211, Finland
| | - Amélie Saunier
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, Kuopio 70211, Finland
| | - James D. Blande
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, Kuopio 70211, Finland
| |
Collapse
|
8
|
Espinosa-García FJ, García-Rodríguez YM, Bravo-Monzón AE, Vega-Peña EV, Delgado-Lamas G. Implications of the foliar phytochemical diversity of the avocado crop Persea americana cv. Hass in its susceptibility to pests and pathogens. PeerJ 2021; 9:e11796. [PMID: 35070514 PMCID: PMC8759378 DOI: 10.7717/peerj.11796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 06/25/2021] [Indexed: 11/20/2022] Open
Abstract
Phytochemical diversity (PD) can be considered as a defensive trait; it can operate through single plant secondary metabolites or usually as complex mixtures of them. We tested the more diversity-better defense hypothesis correlating the leaf plant secondary metabolites (PSMs) with the incidence of plant enemies on Hass avocado trees. We expected a negative correlation between the occurrence of plant enemies and PD metrics. Also, as intraspecific PSMs polymorphisms in plant populations are common, we studied the incidence of plant enemies on Hass avocado trees representing chemical variants (chemotypes). We expected a differential incidence of plant enemies among trees grouped by their mono and sesquiterpene + phenylpropanoid chemotypes. We analyzed foliar hexane extracts from 236 trees in 17 orchards by gas chromatography and for the incidence of red mite, thrips, whitefly, avocado branch borer, fruit rot, scab, and peduncle collar blight. The predicted negative correlation between the plant enemies’ incidence and the phytochemical metrics did not occur. To determine the relationship between enemy incidence and chemotypes we grouped the trees by cluster analysis using a matrix of PSMs in each tree. Most trees were grouped under four out of 23 chemotypes. Branch borers attacked trees of low-frequency chemotypes more frequently than trees with common chemotypes. The incidence of five plant enemies was different among the predominant chemotypes. The hypothesis of more diversity-better defense was not supported by the correlations between the phytochemical diversity and the incidence of pests and pathogens in Hass avocado orchards. Based on our results, we hypothesize that phytochemical diversity function as a defensive trait relies more on differentiation among individuals in a population than on the sole increase of chemical diversity. Also, the differential incidence of pests and pathogens on trees classified by their foliar chemotypes implies that these susceptibility or resistance markers represent potential useful tools for Hass avocado orchard pest management.
Collapse
Affiliation(s)
- Francisco J. Espinosa-García
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | - Yolanda M. García-Rodríguez
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | - Angel E. Bravo-Monzón
- Escuela Nacional de Estudios Superiores Mérida, Universidad Nacional Autónoma de México, Mérida, Yucatán, México
| | - Ernesto V. Vega-Peña
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | | |
Collapse
|
9
|
Whitehead SR, Schneider GF, Dybzinski R, Nelson AS, Gelambi M, Jos E, Beckman NG. Fruits, frugivores, and the evolution of phytochemical diversity. OIKOS 2021. [DOI: 10.1111/oik.08332] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Susan R. Whitehead
- Dept of Biological Sciences, Virginia Polytechnic Inst. and State Univ. Blacksburg VI USA
| | | | - Ray Dybzinski
- School of Environmental Sustainability, Loyola Univ. Chicago IL USA
| | - Annika S. Nelson
- Dept of Biological Sciences, Virginia Polytechnic Inst. and State Univ. Blacksburg VI USA
| | - Mariana Gelambi
- Dept of Biological Sciences, Virginia Polytechnic Inst. and State Univ. Blacksburg VI USA
| | - Elsa Jos
- Dept of Biology and Ecology Center, Utah State Univ. Logan UT USA
| | | |
Collapse
|
10
|
Stenberg JA, Ortiz R. Focused Identification of Germplasm Strategy (FIGS): polishing a rough diamond. CURRENT OPINION IN INSECT SCIENCE 2021; 45:1-6. [PMID: 33166746 DOI: 10.1016/j.cois.2020.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 06/11/2023]
Abstract
Focused Identification of Germplasm Strategy (FIGS) has been advocated as an efficient approach to predict and harness variation in adaptive traits in genebanks or wild populations of plants. However, a weakness of the current FIGS approach is that it only utilizes a priori knowledge of one evolutionary factor: natural selection. Further optimization is needed to capture elusive traits, and this review shows that nonadaptive evolutionary processes (gene flow and genetic drift) should be incorporated to increase precision. Focusing on plant resistance to insect herbivores, we also note that historic selection pressures can be difficult to disentangle, and provide suggestions for successful mining based on eco-evolutionary theory. We conclude that with such refinement FIGS has high potential for enhancing breeding efforts and hence sustainable plant production.
Collapse
Affiliation(s)
- Johan A Stenberg
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, 23053 Alnarp, Sweden.
| | - Rodomiro Ortiz
- Department of Plant Breeding, Swedish University of Agricultural Sciences, PO Box 101, 23053 Alnarp, Sweden
| |
Collapse
|
11
|
Paul RL, Pearse IS, Ode PJ. Fine‐scale plant defence variability increases top‐down control of an herbivore. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13808] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryan L. Paul
- Graduate Degree Program in Ecology and Department of Agricultural Biology Colorado State University Fort Collins CO USA
| | - Ian S. Pearse
- U.S. Geological SurveyFort Collins Science Center Fort Collins CO USA
| | - Paul J. Ode
- Graduate Degree Program in Ecology and Department of Agricultural Biology Colorado State University Fort Collins CO USA
| |
Collapse
|
12
|
Hauri KC, Glassmire AE, Wetzel WC. Chemical diversity rather than cultivar diversity predicts natural enemy control of herbivore pests. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02289. [PMID: 33423331 DOI: 10.1002/eap.2289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 09/28/2020] [Accepted: 10/05/2020] [Indexed: 06/12/2023]
Abstract
Cultivar mixtures have been studied for decades as a means for pest suppression. The literature, however, shows a large variability in outcomes, suggesting that we are unable to create mixtures that consistently suppress insect pests and attract natural enemies. A key gap in our understanding of how cultivar mixtures influence pest control is that few studies have examined the plant traits or mechanisms by which cultivar diversity affects pests and their interactions with natural enemies. The diversity of plant chemistry in a cultivar mixture is one trait dimension that is likely influential for insect ecology because chemical traits alter how predators and herbivores forage and interact. To understand how plant chemical diversity influences herbivores and their interactions with predators, we fully crossed predator presence or absence with monocultures, bicultures, and tricultures of three chemotypes of tomato that differed in odor diversity (terpenes) or surface chemistry (acyl sugars) in a caged field experiment. We found that the direct effects of plant chemotype diversity on herbivore performance were strongest in bicultures and depended on herbivore sex, and these effects typically acted through growth rather than survival. The effects of chemotype diversity on top-down pest suppression by natural enemies differed between classes of chemical diversity. Odor diversity (terpenes) interfered with the ability of predators to hunt effectively, whereas diversity in surface chemistry (acyl sugars) did not. Our results suggest that phytochemical diversity can contribute to pest suppression in agroecosystems, but that implementing it will require engineering cultivar mixtures using trait-based approaches that account for the biology of the pests and natural enemies in the system.
Collapse
Affiliation(s)
- Kayleigh C Hauri
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Andrea E Glassmire
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - William C Wetzel
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
- Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, 49060, USA
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- AgBioResearch, Michigan State University, East Lansing, Michigan, 48824, USA
| |
Collapse
|
13
|
Glassmire AE, Zehr LN, Wetzel WC. Disentangling dimensions of phytochemical diversity: alpha and beta have contrasting effects on an insect herbivore. Ecology 2020; 101:e03158. [PMID: 32745232 DOI: 10.1002/ecy.3158] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/23/2020] [Accepted: 06/18/2020] [Indexed: 11/10/2022]
Abstract
Phytochemical diversity is comprised of two main dimensions-the average (alpha) within-plant neighbors or the difference (beta) in the composition of chemicals between plant neighbors. Research, however, has primarily examined the consequences of phytochemical diversity on herbivore performance through a single dimension, even though diversity is multidimensional. Furthermore, the ecological role of phytochemical diversity is not well understood because each of these dimensions exhibits unique biological effects on herbivore performance. Therefore, it has been difficult to tease apart the relative importance of alpha and beta chemical diversities on plant-herbivore interactions. We experimentally manipulated alpha and beta diversities along a chemical gradient to disentangle the relative effects of these dimensions on the performance of a mobile generalist herbivore, Trichoplusia ni (Hübner), using 16 genotypes from the Solanum pennellii introgression lines. First, we found contrasting effects of alpha and beta diversities on herbivore performance. Second, when comparing diversity across and within chemical classes, herbivore performance was reduced when plant neighbors had greater diversity within chemical classes that are biologically inhibiting at higher quantities (i.e., quantitative defenses such as phenolics and acyl sugars). However, herbivore performance was enhanced when plant neighbors had higher levels of chemical classes that are biologically toxic (i.e., qualitative defenses such as alkaloids). Finally, herbivores performed better on plant dicultures compared to monocultures, and performance was positively associated with plant dicultures only when there were high levels of average alpha diversity within plant neighbors. Our results suggest T. ni generalist caterpillars do better when plant neighbors are chemically different because differences provide options for them to choose or to switch between plants to balance chemical uptake. Overall, herbivores interact with a large diversity of plant chemicals at multiple scales, and our results indicate that not all chemical diversity is equal: specific dimensions of phytochemical diversity have unique effects on the dynamics of herbivore performance.
Collapse
Affiliation(s)
- Andrea E Glassmire
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA.,Kellogg Biological Station, Hickory Corners, Michigan, 49060, USA
| | - Luke N Zehr
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - William C Wetzel
- Department of Entomology, Michigan State University, East Lansing, Michigan, 48824, USA.,Kellogg Biological Station, Hickory Corners, Michigan, 49060, USA.,Ecology, Evolutionary Biology, & Behavior, Michigan State University, East Lansing, Michigan, 48824, USA.,AgBioResearch, Michigan State University, East Lansing, Michigan, 48824, USA
| |
Collapse
|
14
|
Associational effects of plant ontogeny on damage by a specialist insect herbivore. Oecologia 2020; 193:593-602. [PMID: 32621031 DOI: 10.1007/s00442-020-04702-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/30/2020] [Indexed: 10/23/2022]
Abstract
Intraspecific variation in plant traits is a major cause of variation in herbivore feeding and performance. Plant defensive traits change as a plant grows, such that ontogeny may account for a substantial portion of intraspecific trait variation. We tested how the ontogenic stage of an individual plant, of an individual in the context of its neighboring plants, and of a patch of plants with mixed or uniform stages affect plant-herbivore interactions. To do this, we conducted an experimental study of the interactions between Lepidium draba, a perennial brassicaceous weed, and Plutella xylostella, a common herbivore of L. draba. We found that L. draba foliar glucosinolates, secondary metabolites often implicated in defense, decreased in concentration with plant age. In single-stage patches, herbivores performed similarly on L. draba plants of different ages. Furthermore, we found no difference in the cumulative performance of herbivores reared on mixed- or even-staged patches of L. draba. However, in mixed-stage patches, the damage experienced by a focal plant depended on the stage of neighboring plants, suggesting a preference hierarchy of the herbivore among plant stages. In our study, the amount of herbivory depended on the ontogenic neighborhood in which the plant grew. However, from the herbivore's perspective, variation in plant ontogenic stage was unimportant to its success in terms of feeding rate and final weight.
Collapse
|
15
|
Wetzel WC, Whitehead SR. The many dimensions of phytochemical diversity: linking theory to practice. Ecol Lett 2019; 23:16-32. [PMID: 31724320 DOI: 10.1111/ele.13422] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 10/17/2019] [Indexed: 01/11/2023]
Abstract
Research on the ecological and evolutionary roles of phytochemicals has recently progressed from studying single compounds to examining chemical diversity itself. A key conceptual advance enabling this progression is the use of species diversity metrics for quantifying phytochemical diversity. In this perspective, we extend the theory developed for species diversity to further our understanding of what exactly phytochemical diversity is and how its many dimensions impact ecological and evolutionary processes. First, we discuss the major dimensions of phytochemical diversity - richness, evenness, functional diversity, and alpha, gamma and beta diversity. We describe their potential independent roles in biotic interactions and the practical challenges associated with their analysis. Second, we re-analyse the published and unpublished datasets to reveal that the phytochemical diversity experienced by an organism (or observed by a researcher) depends strongly on the scale of the interaction and the total amount of phytochemicals involved. We argue that we must account for these frames of reference to meaningfully understand diversity. Moving from a general notion of phytochemical diversity as a single measure to a precise definition of its multidimensional and multiscale nature yields overlooked testable predictions that will facilitate novel insights about the evolutionary ecology of plant biotic interactions.
Collapse
Affiliation(s)
- William C Wetzel
- Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA.,Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Susan R Whitehead
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| |
Collapse
|
16
|
Koussoroplis AM, Schälicke S, Raatz M, Bach M, Wacker A. Feeding in the frequency domain: coarser-grained environments increase consumer sensitivity to resource variability, covariance and phase. Ecol Lett 2019; 22:1104-1114. [PMID: 31016844 DOI: 10.1111/ele.13267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/10/2019] [Accepted: 03/19/2019] [Indexed: 11/28/2022]
Abstract
Theory predicts that resource variability hinders consumer performance. How this effect depends on the temporal structure of resource fluctuations encountered by individuals remains poorly understood. Combining modelling and growth experiments with Daphnia magna, we decompose the complexity of resource fluctuations and test the effect of resource variance, supply peak timing (i.e. phase) and co-limiting resource covariance along a gradient from high to low frequencies reflecting fine- to coarse-grained environments. Our results show that resource storage can buffer growth at high frequencies, but yields a sensitivity of growth to resource peak timing at lower ones. When two resources covary, negative covariance causes stronger growth depression at low frequencies. However, negative covariance might be beneficial at intermediate frequencies, an effect that can be explained by digestive acclimation. Our study provides a mechanistic basis for understanding how alterations of the environmental grain size affect consumers experiencing variable nutritional quality in nature.
Collapse
Affiliation(s)
- Apostolos-Manuel Koussoroplis
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Aquatic Food Web Interactions group (I.R.T.A), Microorganisms Genome and Environment Lab (L.M.G.E.), UMR CNRS 6023, Université Clermont Auvergne, Aubière, France
| | - Svenja Schälicke
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Michael Raatz
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Moritz Bach
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Alexander Wacker
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Animal Ecology group, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
| |
Collapse
|
17
|
Damestoy T, Brachi B, Moreira X, Jactel H, Plomion C, Castagneyrol B. Oak genotype and phenolic compounds differently affect the performance of two insect herbivores with contrasting diet breadth. TREE PHYSIOLOGY 2019; 39:615-627. [PMID: 30668790 DOI: 10.1093/treephys/tpy149] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/13/2018] [Accepted: 12/19/2018] [Indexed: 05/16/2023]
Abstract
Research on plant-herbivore interactions has long recognized that plant genetic variation plays a central role in driving insect abundance and herbivory, as well as in determining plant defense. However, how plant genes influence herbivore feeding performances, and which plant defensive traits mediate these effects, remain poorly understood. Here we investigated the feeding performances of two insect leaf chewers with contrasting diet breadth (the generalist Lymantria dispar L. and the specialist Thaumetopoea processionea L.) on different genotypes of pedunculate oak (Quercus robur L.) and tested the role of leaf phenolics. We used leaves from four clones of 30 Q. robur full-sibs grown in a common garden to estimate the performance of both herbivores in laboratory feeding trials and to quantify the concentration of constitutive chemical defences (phenolic compounds). We found that tree genetics influenced leaf consumption by T. processionea but not by L. dispar. However genetic variation among trees did not explain growth rate variation in either herbivore nor in leaf phenolics. Interestingly, all phenolic compounds displayed a positive relationship with L. dispar growth rate, and leaf consumption by both herbivores displayed a positive relationship with the concentrations of condensed tannins, suggesting that highly defended leaves could induce a compensatory feeding response. While genetic variation in oaks did not explain herbivore growth rate, we found positive genetic correlations between the two herbivores for leaf consumption and digestion. Overall, we found that oak genotype and phenolic compounds partly and independently contribute to variability in herbivore performance. We challenged the current view of plant-insect interaction and provided little support to the idea that the effect of plant genotype on associated organisms is driven by plant defences. Together, our results point to the existence of genetically determined resistance traits in oaks whose effects differ between herbivores and motivate further research on mechanisms governing oak-herbivore interactions.
Collapse
Affiliation(s)
- Thomas Damestoy
- BIOGECO, INRA, Univ. Bordeaux, 69 route d'Arcachon, Cestas Cedex, France
| | - Benjamin Brachi
- BIOGECO, INRA, Univ. Bordeaux, 69 route d'Arcachon, Cestas Cedex, France
| | - Xoaquín Moreira
- Misión Biológica de Galicia (MBG-CSIC), Apartado de correos 28, Pontevedra, Galicia, Spain
| | - Hervé Jactel
- BIOGECO, INRA, Univ. Bordeaux, 69 route d'Arcachon, Cestas Cedex, France
| | - Christophe Plomion
- BIOGECO, INRA, Univ. Bordeaux, 69 route d'Arcachon, Cestas Cedex, France
| | | |
Collapse
|
18
|
Kessler A, Kalske A. Plant Secondary Metabolite Diversity and Species Interactions. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2018. [DOI: 10.1146/annurev-ecolsys-110617-062406] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ever since the first plant secondary metabolites (PSMs) were isolated and identified, questions about their ecological functions and diversity have been raised. Recent advances in analytical chemistry and complex data computation, as well as progress in chemical ecology from mechanistic to functional and evolutionary questions, open a new box of hypotheses. Addressing these hypotheses includes the measurement of complex traits, such as chemodiversity, in a context-dependent manner and allows for a deeper understanding of the multifunctionality and functional redundancy of PSMs. Here we review a hypothesis framework that addresses PSM diversity on multiple ecological levels (α, β, and γ chemodiversity), its variation in space and time, and the potential agents of natural selection. We use the concept of chemical information transfer as mediator of antagonistic and mutualistic interaction to interpret functional and microevolutionary studies and create a hypothesis framework for understanding chemodiversity as a factor driving ecological processes.
Collapse
Affiliation(s)
- André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853, USA;,
| | - Aino Kalske
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853, USA;,
| |
Collapse
|