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Cuff JP, Evans DM, Vaughan IP, Wilder SM, Tercel MPTG, Windsor FM. Networking nutrients: How nutrition determines the structure of ecological networks. J Anim Ecol 2024; 93:974-988. [PMID: 38946110 DOI: 10.1111/1365-2656.14124] [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: 09/22/2023] [Accepted: 05/29/2024] [Indexed: 07/02/2024]
Abstract
Nutrients can shape ecological interactions but remain poorly integrated into ecological networks. Concepts such as nutrient-specific foraging nevertheless have the potential to expose the mechanisms structuring complex ecological systems. Nutrients also present an opportunity to predict dynamic processes, such as interaction rewiring and extinction cascades, and increase the accuracy of network analyses. Here, we propose the concept of nutritional networks. By integrating nutritional data into ecological networks, we envisage significant advances to our understanding of ecological processes from individual to ecosystem scales. We show that networks can be constructed with nutritional data to illuminate how nutrients structure ecological interactions in natural systems through an empirical example. Throughout, we identify fundamental ecological hypotheses that can be explored in a nutritional network context, alongside methods for resolving those networks. Nutrients influence the structure and complexity of ecological networks through mechanistic processes and concepts including nutritional niche differentiation, functional responses, landscape diversity, ecological invasions and ecosystem robustness. Future research on ecological networks should consider nutrients when investigating the drivers of network structure and function.
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Affiliation(s)
- Jordan P Cuff
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Darren M Evans
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ian P Vaughan
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Shawn M Wilder
- Department of Integrative Biology, 501 Life Sciences West, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Maximillian P T G Tercel
- School of Biosciences, Cardiff University, Cardiff, UK
- Durrell Wildlife Conservation Trust, Trinity, Jersey
| | - Fredric M Windsor
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
- School of Biosciences, Cardiff University, Cardiff, UK
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2
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Gómez-Devia L, Nevo O. Effects of temperature gradient on functional fruit traits: an elevation-for-temperature approach. BMC Ecol Evol 2024; 24:94. [PMID: 38982367 PMCID: PMC11232184 DOI: 10.1186/s12862-024-02271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 06/12/2024] [Indexed: 07/11/2024] Open
Abstract
Fruit traits mediate animal-plant interactions and have to a large degree evolved to match the sensory capacities and morphology of their respective dispersers. At the same time, fruit traits are affected by local environmental factors, which may affect frugivore-plant trait match. Temperature has been identified as a major factor with a strong effect on the development of fruits, which is of serious concern because of the rising threat of global warming. Nonetheless, this primarily originates from studies on domesticated cultivars in often controlled environments. Little is known on the effect of rising temperatures on fruit traits of wild species and the implications this could have to seed dispersal networks, including downstream consequences to biodiversity and ecosystem functioning. In a case study of five plant species from eastern Madagascar, we addressed this using the elevation-for-temperature approach and examined whether a temperature gradient is systematically associated with variation in fruit traits relevant for animal foraging and fruit selection. We sampled across a gradient representing a temperature gradient of 1.5-2.6 °C, corresponding to IPCC projections. The results showed that in most cases there was no significant effect of temperature on the traits evaluated, although some species showed different effects, particularly fruit chemical profiles. This suggests that in these species warming within this range alone is not likely to drive substantial changes in dispersal networks. While no systemic effects were found, the results also indicate that the effect of temperature on fruit traits differs across species and may lead to mismatches in specific animal-plant interactions.
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Affiliation(s)
- Laura Gómez-Devia
- German Centre for Integrative Biodiversity Research (iDiv) , Halle-Jena-Leipzig, Germany.
- Global Change Research Group, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain.
- Technische Universität Dresden, Dresden, Germany.
| | - Omer Nevo
- German Centre for Integrative Biodiversity Research (iDiv) , Halle-Jena-Leipzig, Germany
- Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
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3
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DePasquale AN, Poirier AC, Mah MA, Villalobos Suarez C, Guadamuz A, Cheves Hernandez S, Lopez Navarro R, Hogan JD, Rothman JM, Nevo O, Melin AD. Picking pithy plants: Pith selectivity by wild white-faced capuchin monkeys, Cebus imitator. Am J Primatol 2023:e23549. [PMID: 37690098 DOI: 10.1002/ajp.23549] [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: 04/12/2023] [Revised: 08/11/2023] [Accepted: 08/31/2023] [Indexed: 09/12/2023]
Abstract
Understanding diet selectivity is a longstanding goal in primate ecology. Deciphering when and why primates consume different resources can provide insights into their nutritional ecology as well as adaptations to food scarcity. Plant pith, the spongy interior of plant stems, is occasionally eaten by primates, but the context is poorly understood. We examine the ecological, mechanical, chemical, and nutritional basis of plant pith selection by a wild, frugivorous-omnivorous primate (Cebus imitator). We test the hypothesis that pith is a fallback food, that is, consumed when fruit is less abundant, and test for differences between plant species from which pith is eaten versus avoided. We collected 3.5 years of capuchin pith consumption data to document dietary species and analyzed "pith patch visits" in relation to fruit availability, visits to fruit patches, and climatic seasonality. We analyzed dietary and non-dietary species for relative pith quantity, mechanical hardness, odor composition, and macronutrient concentrations. Capuchins ate pith from 11 of ~300 plant species common in the dry forest, most commonly Bursera simaruba. We find that pith consumption is not directly related to fruit availability or fruit foraging but occurs most frequently (84% of patch visits) during the months of seasonal transition. Relative to common non-dietary species, dietary pith species have relatively higher pith quantity, have softer outer branches and pith, and contain more terpenoids, a class of bioactive compounds notable for their widespread medicinal properties. Our results suggest that greater pith quantity, lower hardness, and a more complex, terpenoid-rich odor profile contribute to species selectivity; further, as pith is likely to be consistently available throughout the year, the seasonality of pith foraging may point to zoopharmacognosy, as seasonal transitions typically introduce new parasites or pathogens. Our study furthers our understanding of how climatic seasonality impacts primate behavior and sheds new light on food choice by an omnivorous primate.
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Affiliation(s)
- Allegra N DePasquale
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Alice C Poirier
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Megan A Mah
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | | | | | | - Jessica M Rothman
- Department of Anthropology, CUNY Hunter College, New York, New York, USA
| | - Omer Nevo
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
| | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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4
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Barnett JR, Tieman DM, Caicedo AL. Variation in ripe fruit volatiles across the tomato clade: An evolutionary framework for studying fruit scent diversity in a crop wild relative. AMERICAN JOURNAL OF BOTANY 2023; 110:e16223. [PMID: 37551422 DOI: 10.1002/ajb2.16223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 08/09/2023]
Abstract
PREMISE The scents of volatile organic compounds (VOCs) are an important component of ripe fleshy fruit attractiveness, yet their variation across closely related wild species is poorly understood. Phylogenetic patterns in these compounds and their biosynthetic pathways offer insight into the evolutionary drivers of fruit diversity, including whether scent can communicate an honest signal of nutrient content to animal dispersers. We assessed ripe fruit VOC content across the tomato clade (Solanum sect. Lycopersicon), with implications for crop improvement since these compounds are key components of tomato flavor. METHODS We analyzed ripe fruit volatiles from 13 species of wild tomato grown in a common garden. Interspecific variations in 66 compounds and their biosynthetic pathways were assessed in 32 accessions, and an accession-level phylogeny was constructed to account for relatedness. RESULTS Wild tomato species can be differentiated by their VOCs, with Solanum pennellii notably distinct. Phylogenetic conservatism exists to a limited extent. Major cladewide patterns corresponded to divergence of the five brightly colored-fruited species from the nine green-fruited species, particularly for nitrogen-containing compounds (higher in colored-fruited) and esters (higher in green-fruited), the latter appearing to signal a sugar reward. CONCLUSIONS We established a framework for fruit scent evolution studies in a crop wild relative system, showing that each species in the tomato clade has a unique VOC profile. Differences between color groups align with fruit syndromes that could be driven by selection from frugivores. The evolution of colored fruits was accompanied by changes in biosynthetic pathways for esters and nitrogen-containing compounds, volatiles important to tomato flavor.
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Affiliation(s)
- Jacob R Barnett
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts Amherst, MA, 01003, USA
| | - Denise M Tieman
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA
| | - Ana L Caicedo
- Department of Biology, University of Massachusetts Amherst, MA, 01003, USA
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5
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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.
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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
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6
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Casorso JG, DePasquale AN, Romero Morales S, Cheves Hernandez S, Lopez Navarro R, Hockings KJ, Carrigan MA, Melin AD. Seed dispersal syndrome predicts ethanol concentration of fruits in a tropical dry forest. Proc Biol Sci 2023; 290:20230804. [PMID: 37464751 DOI: 10.1098/rspb.2023.0804] [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: 04/04/2023] [Accepted: 06/22/2023] [Indexed: 07/20/2023] Open
Abstract
Studying fruit traits and their interactions with seed dispersers can improve how we interpret patterns of biodiversity, ecosystem function and evolution. Mounting evidence suggests that fruit ethanol is common and variable, and may exert selective pressures on seed dispersers. To test this, we comprehensively assess fruit ethanol content in a wild ecosystem and explore sources of variation. We hypothesize that both phylogeny and seed dispersal syndrome explain variation in ethanol levels, and we predict that fruits with mammalian dispersal traits will contain higher levels of ethanol than those with bird dispersal traits. We measured ripe fruit ethanol content in species with mammal- (n = 16), bird- (n = 14) or mixed-dispersal (n = 7) syndromes in a Costa Rican tropical dry forest. Seventy-eight per cent of fruit species yielded measurable ethanol concentrations. We detected a phylogenetic signal in maximum ethanol levels (Pagel's λ = 0.82). Controlling for phylogeny, we observed greater ethanol concentrations in mammal-dispersed fruits, indicating that dispersal syndrome helps explain variation in ethanol content, and that mammals may be more exposed to ethanol in their diets than birds. Our findings further our understanding of wild fruit ethanol and its potential role as a selective pressure on frugivore sensory systems and metabolism.
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Affiliation(s)
- Julia G Casorso
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Allegra N DePasquale
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | | | | | | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
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7
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Nevo O, Valenta K, Helman A, Ganzhorn JU, Ayasse M. Fruit scent as an honest signal for fruit quality. BMC Ecol Evol 2022; 22:139. [PMID: 36451093 PMCID: PMC9710009 DOI: 10.1186/s12862-022-02064-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/15/2022] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Fleshy fruits evolved to be attractive to seed dispersers through various signals such as color and scent. Signals can evolve through different trajectories and have various degrees of reliability. The strongest substrate on which reliable signals can evolve is when there is an inherent link between signal and reward, rendering cheating costly or impossible. It was recently proposed that aliphatic esters in fruit scent may be predictive of sugar content due to their synthesis from products of sugar fermentation. We test this hypothesis on a case study of wild fig species (Ficus tiliifolia) from Madagascar, which relies on seed dispersal by lemurs. RESULTS We found a strong positive correlation between signal (esters) and reward (sugar). We also found that non-esters, including direct fermentation products, in fruit scent do not indicate sugar levels, which implies that this relationship is not simply a product of fruit maturation wherein more mature fruits emit more scent and contain more sugar. CONCLUSIONS While based on a single taxon, these results strongly support the hypothesis that a biochemical link between ester synthesis and sugar may render the ester fraction of fruit scent an honest signal for fruit quality, with consequences for animal sensory and feeding ecology, and the evolution of plants in the context of seed dispersal.
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Affiliation(s)
- Omer Nevo
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany. .,Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany. .,Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany.
| | - Kim Valenta
- grid.15276.370000 0004 1936 8091Department of Anthropology, University of Florida, Gainesville, FL USA
| | - Annabella Helman
- grid.26009.3d0000 0004 1936 7961Department of Evolutionary Anthropology, Duke University, Durham, NC USA
| | - Jörg U. Ganzhorn
- grid.9026.d0000 0001 2287 2617Animal Ecology and Conservation, University of Hamburg, Hamburg, Germany
| | - Manfred Ayasse
- grid.6582.90000 0004 1936 9748Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
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8
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Valenta K, Nevo O. The illusiveness of seed dispersal syndromes. A commentary on: Fleshy fruit traits and seed dispersers: which traits define syndromes? ANNALS OF BOTANY 2022; 129:vi-vii. [PMID: 35139151 PMCID: PMC9292597 DOI: 10.1093/aob/mcac009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
| | - Omer Nevo
- German Centre of Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biodiversity, Friedrich-Schiller University Jena, Jena, Germany
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9
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Johnson SD, Govender K. Rodent responses to volatile compounds provide insights into the function of floral scent in mammal-pollinated plants. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210167. [PMID: 35491600 DOI: 10.1098/rstb.2021.0167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Flowers pollinated by mammals have evolved in many plant families. Several scent compounds that attract bats to flowers have been identified, but the chemical ecology of pollination mutualisms between plants and ground-dwelling mammals is poorly understood. Rodents are key pollinators in South Africa and rely heavily on olfaction to locate food. Our aim was to identify compounds that may function to attract rodents to flowers. Eighteen volatile compounds, including 14 that are prominent in the scent of rodent-pollinated flowers, were used in choice experiments involving wild-caught individuals of four native rodent species. Rodents were generally attracted to oxygenated aliphatic compounds, specifically ketones and esters, but not to some aromatic compounds common in floral scents of insect-pollinated species, nor to a sulfide compound that is attractive to bats. Associative conditioning using sugar solution as a reward had only weak effects on the attractiveness of compounds to rodents. The attractive effect of some compounds disappeared when they were blended with compounds that did not attract rodents. We conclude that aliphatic ketones and esters are likely to play a key role in attracting rodents to flowers. Deployment of these compounds may allow plants to exploit rodent sensory bias that evolved in other contexts such as intra-specific communication and searching for seeds. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Steven D Johnson
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
| | - Keeveshnee Govender
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
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10
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Fruit Fly Larval Survival in Picked and Unpicked Tomato Fruit of Differing Ripeness and Associated Gene Expression Patterns. INSECTS 2022; 13:insects13050451. [PMID: 35621786 PMCID: PMC9146954 DOI: 10.3390/insects13050451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/01/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022]
Abstract
The larvae of frugivorous tephritid fruit flies feed within fruit and are global pests of horticulture. With the reduced use of pesticides, alternative control methods are needed, of which fruit resistance is one. In the current study, we explicitly tested for phenotypic evidence of induced fruit defences by running concurrent larval survival experiments with fruit on or off the plant, assuming that defence induction would be stopped or reduced by fruit picking. This was accompanied by RT-qPCR analysis of fruit defence and insect detoxification gene expression. Our fruit treatments were picking status (unpicked vs. picked) and ripening stage (colour break vs. fully ripe), our fruit fly was the polyphagous Bactrocera tryoni, and larval survival was assessed through destructive fruit sampling at 48 and 120 h, respectively. The gene expression study targeted larval and fruit tissue samples collected at 48 h and 120 h from picked and unpicked colour-break fruit. At 120 h in colour-break fruit, larval survival was significantly higher in the picked versus unpicked fruit. The gene expression patterns in larval and plant tissue were not affected by picking status, but many putative plant defence and insect detoxification genes were upregulated across the treatments. The larval survival results strongly infer an induced defence mechanism in colour-break tomato fruit that is stronger/faster in unpicked fruits; however, the gene expression patterns failed to provide the same clear-cut treatment effect. The lack of conformity between these results could be related to expression changes in unsampled candidate genes, or due to critical changes in gene expression that occurred during the unsampled periods.
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11
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Affiliation(s)
- Juan Manuel Morales
- Grupo de Ecología Cuantitativa, INIBIOMA‐CONICET, Univ. Nacional del Comahue Bariloche Argentina
| | - Teresa Morán López
- Grupo de Ecología Cuantitativa, INIBIOMA‐CONICET, Univ. Nacional del Comahue Bariloche Argentina
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12
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Fruit secondary metabolites shape seed dispersal effectiveness. Trends Ecol Evol 2021; 36:1113-1123. [PMID: 34509316 DOI: 10.1016/j.tree.2021.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/22/2022]
Abstract
Plant secondary metabolites (PSMs) play a central role in seed dispersal and fruit defense, with potential for large impacts on plant fitness and demography. Yet because PSMs can have multiple interactive functions across seed dispersal stages, we must systematically study their effects to determine the net consequences for plant fitness. To tackle this issue, we integrate the role of fruit PSMs into the seed dispersal effectiveness (SDE) framework. We describe PSM effects on the quantity and quality of animal-mediated seed dispersal, both in pairwise interactions and diverse disperser communities, as well as trade-offs that occur across dispersal stages. By doing so, this review provides structure to a rapidly growing field and yields insights into a critical process shaping plant populations.
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13
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Tang J, Poirier AC, Duytschaever G, Moreira LAA, Nevo O, Melin AD. Assessing urinary odours across the oestrous cycle in a mouse model using portable and benchtop gas chromatography-mass spectrometry. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210172. [PMID: 34540244 PMCID: PMC8411304 DOI: 10.1098/rsos.210172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 08/09/2021] [Indexed: 05/06/2023]
Abstract
For female mammals, communicating the timing of ovulation is essential for reproduction. Olfactory communication via volatile organic compounds (VOCs) can play a key role. We investigated urinary VOCs across the oestrous cycle using laboratory mice. We assessed the oestrous stage through daily vaginal cytology and analysed urinary VOCs using headspace gas chromatography-mass spectrometry (GC-MS), testing a portable GC-MS against a benchtop system. We detected 65 VOCs from 40 samples stored in VOC traps and analysed on a benchtop GC-MS, and 15 VOCs from 90 samples extracted by solid-phase microextraction (SPME) and analysed on a portable GC-MS. Only three compounds were found in common between the two techniques. Urine collected from the fertile stages of the oestrous cycle had increased quantities of a few notable VOCs compared with urine from non-fertile stages. These VOCs may be indicators of fertility. However, we did not find significant differences in chemical composition among oestrous stages. It is possible that changes in VOC abundance were too small to be detected by our analytical methods. Overall, the use of VOC traps combined with benchtop GC-MS was the more successful of the two methods, yet portable GC-MS systems may still have utility for some in situ applications.
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Affiliation(s)
- Jia Tang
- Department of Anthropology and Archaeology, University of Calgary, Canada
| | - Alice C. Poirier
- Department of Anthropology and Archaeology, University of Calgary, Canada
| | - Gwen Duytschaever
- Department of Anthropology and Archaeology, University of Calgary, Canada
| | - Laís A. A. Moreira
- Department of Anthropology and Archaeology, University of Calgary, Canada
| | - Omer Nevo
- German Centre of Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany
- Institute of Biodiversity, Friedrich Schiller University Jena, Germany
| | - Amanda D. Melin
- Department of Anthropology and Archaeology, University of Calgary, Canada
- Department of Medical Genetics, University of Calgary, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Canada
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14
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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
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15
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Cunningham EP, Edmonds D, Stalter L, Janal MN. Ring-tailed lemurs (Lemur catta) use olfaction to locate distant fruit. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 175:300-307. [PMID: 33624841 DOI: 10.1002/ajpa.24255] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/28/2021] [Accepted: 02/05/2021] [Indexed: 12/22/2022]
Abstract
OBJECTIVES As many primates live in forests where visibility is limited, the ability to detect the aroma of distant fruit and navigate odor plumes would be highly adaptive. Our study is the first to investigate this ability with strepsirrhine primates. MATERIALS AND METHODS We tested the ability of a group of ring-tailed lemurs to detect hidden fruit from afar using scent alone. We hid containers in the underbrush of a semi-natural forest, some baited with real cantaloupe and some with sham cantaloupe, 4-17 m from a path routinely used by the lemurs. Crucially, the containers were not visible from the path. Therefore, the lemurs had to use olfactory cues, but did not have to prioritize them to locate the bait. RESULTS The lemurs found the real cantaloupe on days that the wind blew the scent of the fruit toward the trail. They did not find the sham cantaloupe. Upon detecting the odor of the bait, the lemurs sniffed the air at one or more locations as they moved toward the bait, a process of navigation known as klinotaxis. DISCUSSION The traditional belief is that primates are unable to track odor plumes. The untrained lemurs in this study were able to detect the odor of the cantaloupe among the complex odors of the forest and navigate the odor plume to the fruit. The results indicate that olfaction may be used to respond to cues from distant sources. The ability to track odor plumes may be a critical foraging skill for strepsirrhines.
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Affiliation(s)
- Elena P Cunningham
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, 10010, USA
| | - Devin Edmonds
- Lemur Conservation Foundation, Myakka City, Florida, USA.,Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
| | - Laura Stalter
- Lemur Conservation Foundation, Myakka City, Florida, USA.,University of Vermont, Burlington, Vermont, USA
| | - Malvin N Janal
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, 10010, USA.,Department of Epidemiology and Health Promotion, New York University College of Dentistry, Burlington, Vermont, USA
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Pizo MA, Morales JM, Ovaskainen O, Carlo TA. Frugivory Specialization in Birds and Fruit Chemistry Structure Mutualistic Networks across the Neotropics. Am Nat 2021; 197:236-249. [PMID: 33523785 DOI: 10.1086/712381] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractThe interaction between fruit chemistry and the physiological traits of frugivores is expected to shape the structure of mutualistic seed dispersal networks, but it has been understudied compared with the role of morphological trait matching in structuring interaction patterns. For instance, highly frugivorous birds (i.e., birds that have fruits as the main component of their diets), which characteristically have fast gut passage times, are expected to avoid feeding on lipid-rich fruits because of the long gut retention times associated with lipid digestion. Here, we compiled data from 84 studies conducted in the Neotropics that used focal plant methods to record 35,815 feeding visits made by 317 bird species (155 genera in 28 families) to 165 plant species (82 genera in 48 families). We investigated the relationship between the degree of frugivory of birds (i.e., how much of their diet is composed of fruit) at the genus level and their visits to plant genera that vary in fruit lipid content. We used a hierarchical modeling of species communities approach that accounted for the effects of differences in body size, bird and plant phylogeny, and spatial location of study sites. We found that birds with a low degree of frugivory (e.g., predominantly insectivores) tend to have the highest increase in visitation rates as fruits become more lipid rich, while birds that are more frugivorous tend to increase visits at a lower rate or even decrease visitation rates as lipids increase in fruits. This balance between degree of frugivory and visitation rates to lipid-poor and lipid-rich fruits provides a mechanism to explain specialized dispersal systems and the occurrence of certain physiological nutritional filters, ultimately helping us to understand community-wide interaction patterns between birds and plants.
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Affiliation(s)
- Kim J. E. Steffens
- Department of Biology, Institute of Zoology University of Hamburg Martin‐Luther‐King Platz 3, 20146 Hamburg Germany
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Nevo O, Valenta K, Kleiner A, Razafimandimby D, Jeffrey JAJ, Chapman CA, Ayasse M. The evolution of fruit scent: phylogenetic and developmental constraints. BMC Evol Biol 2020; 20:138. [PMID: 33109084 PMCID: PMC7590443 DOI: 10.1186/s12862-020-01708-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 10/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fruit scent is increasingly recognized as an evolved signal whose function is to attract animal seed dispersers and facilitate plant reproduction. However, like all traits, fruit scent is likely to evolve in response to conflicting selective pressures and various constraints. Two major constraints are (i) phylogenetic constraints, in which traits are inherited from ancestors rather than adapted to current conditions and (ii) developmental constraints, if phenotypes are limited by the expression of other traits within the individual. We tested whether phylogenetic constraints play a role in fruit scent evolution by calculating the phylogenetic signal in ripe fruits of 98 species from three study sites. We then estimated the importance of developmental constraints by examining whether ripe fruits tend to emit compounds that are chemically similar to, and share biosynthetic pathways with, compounds emitted by conspecific unripe fruits from which they develop. RESULTS We show that closely related taxa are not more similar to each other than to very distinct taxa, thus indicating that fruit scent shows little phylogenetic signal. At the same time, although ripe and unripe fruits of the same species tend to emit different chemicals, they tend to employ chemicals originating from similar biosynthetic pathways, thus indicating that some developmental constraints determine ripe fruit scent. CONCLUSIONS Our results highlight the complex landscape in which fruit scent has evolved. On one hand, fruit scent evolution is not limited by common ancestry. On the other hand, the range of chemicals that can be employed in ripe fruits is probably constrained by the needs of unripe fruits.
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Affiliation(s)
- Omer Nevo
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103 Leipzig, Germany
- Institute of Biodiversity, Friedrich Schiller University Jena, Dornburgerstr 159, 07743 Jena, Germany
| | - Kim Valenta
- Department of Anthropology, University of Florida, Gainesville, FL USA
| | - Annemarie Kleiner
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
| | - Diary Razafimandimby
- Faculty of Sciences, Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Juan Antonio James Jeffrey
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT USA
- School of Medicine, Case Western Reserve University, Cleveland, OH USA
| | - Colin A. Chapman
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20037 USA
- School of Life Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, South Africa
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, China
| | - Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany
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Nevo O, Schmitt MH, Ayasse M, Valenta K. Sweet tooth: Elephants detect fruit sugar levels based on scent alone. Ecol Evol 2020; 10:11399-11407. [PMID: 33144973 PMCID: PMC7593167 DOI: 10.1002/ece3.6777] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/07/2020] [Accepted: 08/18/2020] [Indexed: 11/10/2022] Open
Abstract
The ability to assess food quality is crucial to all organisms. Fleshy fruits are a major source of nutrients to various animals, and unlike most food sources, have evolved to be attractive and to be consumed by animals to promote seed dispersal. It has recently been established that fruit scent-the bouquet of volatile chemicals emitted by ripe fruit-is an evolved communication system between plants and animals. Further, it has been argued that chemicals that are synthesized from sugar and its products may be an honest signal for sugar content and fruit quality. Elephants are important seed dispersers for numerous species and possess an olfactory system that is likely to outperform most other animals. We tested the hypothesis that fruit scent signifies sugar content and that elephants are capable of assessing fruit sugar levels based on scent alone. Using a paired-choice test of marula fruits (Sclerocarya birrea) by semitame African elephants, we show that elephants are capable of identifying more sugar-rich fruits based on scent alone and that this is likely based on two chemical compounds: ethanol and ethyl acetate, both downstream products of sugar fermentation. These results shed light on the mechanisms driving elephant feeding ecology, plant signaling, and the coevolutionary process between angiosperms and animal seed dispersers.
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Affiliation(s)
- Omer Nevo
- Institute of Evolutionary Ecology and Conservation GenomicsUlm UniversityUlmGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiodiversityFriedrich Schiller University JenaJenaGermany
| | - Melissa H. Schmitt
- Department of Ecology, Evolution, and Marine BiologyUniversity of California Santa BarbaraSanta BarbaraCAUSA
- South African Environmental Observation NetworkNdlovu NodePhalaborwaSouth Africa
| | - Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation GenomicsUlm UniversityUlmGermany
| | - Kim Valenta
- Department of AnthropologyUniversity of FloridaGainesvilleFLUSA
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20
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Valenta K, Nevo O. The dispersal syndrome hypothesis: How animals shaped fruit traits, and how they did not. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13564] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Kim Valenta
- Department of Anthropology University of Florida Gainesville FL USA
| | - Omer Nevo
- Institute of Evolutionary Ecology and Conservation Genomics Ulm University Ulm Germany
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