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Perkins J, Hayashi T, Peakall R, Flematti GR, Bohman B. The volatile chemistry of orchid pollination. Nat Prod Rep 2023; 40:819-839. [PMID: 36691832 DOI: 10.1039/d2np00060a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Covering: up to September 2022Orchids are renowned not only for their diversity of floral forms, but also for their many and often highly specialised pollination strategies. Volatile semiochemicals play a crucial role in the attraction of a wide variety of insect pollinators of orchids. The compounds produced by orchid flowers are as diverse as the pollinators they attract, and here we summarise some of the chemical diversity found across orchid taxa and pollination strategies. We focus on compounds that have been experimentally demonstrated to underpin pollinator attraction. We also highlight the structural elucidation and synthesis of a select subset of important orchid pollinator attractants, and discuss the ecological significance of the discoveries, the gaps in our current knowledge of orchid pollination chemistry, and some opportunities for future research in this field.
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Affiliation(s)
- James Perkins
- Research School of Biology, The Australian National University, Australia
| | - Tobias Hayashi
- Research School of Biology, The Australian National University, Australia
| | - Rod Peakall
- Research School of Biology, The Australian National University, Australia.,School of Molecular Sciences, The University of Western Australia, Australia
| | - Gavin R Flematti
- School of Molecular Sciences, The University of Western Australia, Australia
| | - Björn Bohman
- Research School of Biology, The Australian National University, Australia.,School of Molecular Sciences, The University of Western Australia, Australia.,Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Sweden.
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2
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Eisen KE, Ma R, Raguso RA. Among- and within-population variation in morphology, rewards, and scent in a hawkmoth-pollinated plant. AMERICAN JOURNAL OF BOTANY 2022; 109:1794-1810. [PMID: 35762273 DOI: 10.1002/ajb2.16030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Floral scent is a complex trait that mediates many plant-insect interactions, but our understanding of how floral scent variation evolves, either independently or in concert with other traits, remains limited. Assessing variation in floral scent at multiple levels of biological organization and comparing patterns of variation in scent to variation in other floral traits can contribute to our understanding of how scent variation evolves in nature. METHODS We used a greenhouse common garden experiment to investigate variation in floral scent at three scales-within plants, among plants, and among populations-and to determine whether scent, alone or in combination with morphology and rewards, contributes to population differentiation in Oenothera cespitosa subsp. marginata. Its range spans most of the biomes in the western United States, such that variation in both the abiotic and biotic environment could contribute to trait variation. RESULTS Multiple analytical approaches demonstrated substantial variation among and within populations in compound-specific and total floral scent measures. Overall, populations were differentiated in morphology and reward traits and in scent. Across populations, coupled patterns of variation in linalool, leucine-derived compounds, and hypanthium length are consistent with a long-tongued moth pollination syndrome. CONCLUSIONS The considerable variation in floral scent detected within populations suggests that, similar to other floral traits, variation in floral scent may have a heritable genetic component. Differences in patterns of population differentiation in floral scent and in morphology and rewards indicate that these traits may be shaped by different selective pressures.
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Affiliation(s)
- Katherine E Eisen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
- Department of Biology, Lund University, Lund, Sweden
| | - Rong Ma
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
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3
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Opedal ØH, Gross K, Chapurlat E, Parachnowitsch A, Joffard N, Sletvold N, Ovaskainen O, Friberg M. Measuring, comparing and interpreting phenotypic selection on floral scent. J Evol Biol 2022; 35:1432-1441. [PMID: 36177776 PMCID: PMC9828191 DOI: 10.1111/jeb.14103] [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: 04/21/2022] [Revised: 09/04/2022] [Accepted: 09/07/2022] [Indexed: 01/12/2023]
Abstract
Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with previous analyses in terms of identifying populations and scent compounds subject to stronger selection but also allowed us to evaluate and compare the strength of selection on scent across studies. Doing so revealed that selection on floral scent was highly variable, and overall about as common and as strong as selection on other phenotypic traits involved in pollinator attraction or pollen transfer. These results are consistent with an important role of floral scent in pollinator attraction. Our approach should be useful for further studies of plant-animal communication and for studies of selection on other high-dimensional phenotypes. In particular, our approach will be useful for studies of pollinator-mediated selection on complex scent blends comprising many volatiles, and when no prior information on the physiological responses of pollinators to scent compounds is available.
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Affiliation(s)
| | - Karin Gross
- Department of Environment & BiodiversityParis Lodron University of SalzburgSalzburgAustria
| | - Elodie Chapurlat
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBCUppsala UniversityUppsalaSweden,Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Amy Parachnowitsch
- Department of BiologyUniversity of New BrunswickFrederictonNew BrunswickCanada
| | - Nina Joffard
- University of Lille, UMR 8198 – Evo‐Eco‐PaleoLilleFrance
| | - Nina Sletvold
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBCUppsala UniversityUppsalaSweden
| | - Otso Ovaskainen
- Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskyläFinland,Organismal and Evolutionary Biology Research ProgrammeUniversity of HelsinkiHelsinkiFinland,Centre for Biodiversity Dynamics, Department of BiologyNorwegian University of Science and TechnologyTrondheimNorway
| | - Magne Friberg
- Biodiversity Unit, Department of BiologyLund UniversityLundSweden
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4
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Eisen KE, Powers JM, Raguso RA, Campbell DR. An analytical pipeline to support robust research on the ecology, evolution, and function of floral volatiles. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1006416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Research on floral volatiles has grown substantially in the last 20 years, which has generated insights into their diversity and prevalence. These studies have paved the way for new research that explores the evolutionary origins and ecological consequences of different types of variation in floral scent, including community-level, functional, and environmentally induced variation. However, to address these types of questions, novel approaches are needed that can handle large sample sizes, provide quality control measures, and make volatile research more transparent and accessible, particularly for scientists without prior experience in this field. Drawing upon a literature review and our own experiences, we present a set of best practices for next-generation research in floral scent. We outline methods for data collection (experimental designs, methods for conducting field collections, analytical chemistry, compound identification) and data analysis (statistical analysis, database integration) that will facilitate the generation and interpretation of quality data. For the intermediate step of data processing, we created the R package bouquet, which provides a data analysis pipeline. The package contains functions that enable users to convert chromatographic peak integrations to a filtered data table that can be used in subsequent statistical analyses. This package includes default settings for filtering out non-floral compounds, including background contamination, based on our best-practice guidelines, but functions and workflows can be easily customized as necessary. Next-generation research into the ecology and evolution of floral scent has the potential to generate broadly relevant insights into how complex traits evolve, their genomic architecture, and their consequences for ecological interactions. In order to fulfill this potential, the methodology of floral scent studies needs to become more transparent and reproducible. By outlining best practices throughout the lifecycle of a project, from experimental design to statistical analysis, and providing an R package that standardizes the data processing pipeline, we provide a resource for new and seasoned researchers in this field and in adjacent fields, where high-throughput and multi-dimensional datasets are common.
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5
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Skogen KA, Jogesh T, Hilpman ET, Todd SL, Raguso RA. Extensive population-level sampling reveals clinal variation in (R)-(-)-linalool produced by the flowers of an endemic evening primrose, Oenothera harringtonii. PHYTOCHEMISTRY 2022; 200:113185. [PMID: 35436476 DOI: 10.1016/j.phytochem.2022.113185] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
The study of floral trait diversity has a long history due to its role in angiosperm diversification. While many studies have focused on visual traits including morphology and color, few have included floral scent despite its importance in pollination. Of the studies that have included floral scent, sampling has been limited and rarely explores variation at the population level. We studied geographic variation in the flowers of Oenothera harringtonii, a rare plant endemic to a vulnerable shortgrass prairie habitat, whose population structure and conservation status are well studied. The self-incompatible flowers of O. harringtonii open at dusk, produce nectar and a strong fragrance, and are pollinated by hawkmoths. We collected floral trait (morphology, scent chemistry and emission rates) data from 650 individuals from 19 wild populations to survey floral variation across the entire range of this species. Similarly, we collected floral data from 49 individuals grown in a greenhouse common garden, to assess whether variation observed in the field is consistent when environment factors (temperature, watering regime, soil) are standardized. We identified 35 floral volatiles representing 5 biosynthetic classes. Population differentiation was stronger for floral scent chemistry than floral morphology. (R)-(-)-linalool was the most important floral trait differentiating populations, exhibiting clinal variation across the distribution of O. harringtonii without any correlated shifts in floral morphology. Populations in the north and west produced (R)-(-)-linalool consistently, those in the east and south largely lacked it, and populations at the center of the distribution were polymorphic. Floral scent emissions in wild populations varied across four years but chemical composition was largely consistent over time. Similarly, volatile emission rates and chemical composition in greenhouse-grown plants were consistent with those of wild populations of origin. Our data set, which represents the most extensive population-level survey of floral scent to date, indicates that such sampling may be needed to capture potentially adaptive geographic variation in wild populations.
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Affiliation(s)
- Krissa A Skogen
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60035, USA.
| | - Tania Jogesh
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60035, USA
| | - Evan T Hilpman
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60035, USA; School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Sadie L Todd
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60035, USA; Iowa Department of Agriculture and Land Stewardship, Ankeny, IA, 50023, USA
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
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6
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D'Auria M, Lorenz R, Mecca M, Racioppi R, Romano VA, Viggiani L. Fragrance components of Gymnadenia conopsea and Gymnadenia odoratissima collected at several sites in Italy and Germany. Nat Prod Res 2022; 36:3435-3439. [PMID: 33249883 DOI: 10.1080/14786419.2020.1851227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/01/2020] [Accepted: 11/09/2020] [Indexed: 10/22/2022]
Abstract
The SPME-GC-MS analysis of the aroma components of Gymnadenia conopsea subsp. conopsea, subsp. densiflora, var. alpina and Gymnadenia odoratissima var. odoratissima, var. idae were reported. The main components of in total 78 found in G. conopsea subsp. conopsea were elemicin, cis-9-hexadecenal, hexadecanal, isoelemicin and (Z)-11-hexadecen-1-ol acetate; in subsp. densiflora benzyl benzoate, eugenol and trans-isoeugenol; in var. alpina benzyl benzoate, methyleugenol and elemicin. In the scent of G. odoratissima var. odoratissima were found 2-phenylethyl acetate, eugenol and pentadecane, in var. idae mainly C15-C21 alkanes and C16, C18 carbonic acids and some isoprenoid-derivatives. As all tested Gymnadenia-taxa are allogamous, the differences in scent composition may play a role in pollinator attraction.
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Affiliation(s)
- Maurizio D'Auria
- Dipartimento di Scienze, Università della Basilicata, Potenza, Italy
| | - Richard Lorenz
- Arbeitskreis Heimische Orchideen Baden-Württemberg, Weinheim, Germany
| | - Marisabel Mecca
- Dipartimento di Scienze, Università della Basilicata, Potenza, Italy
| | - Rocco Racioppi
- Dipartimento di Scienze, Università della Basilicata, Potenza, Italy
| | | | - Licia Viggiani
- Dipartimento di Scienze, Università della Basilicata, Potenza, Italy
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7
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Keefover-Ring K, Hetherington MC, Brunet J. Population-specific responses of floral volatiles to abiotic factors in changing environments. AMERICAN JOURNAL OF BOTANY 2022; 109:676-688. [PMID: 35435247 DOI: 10.1002/ajb2.1846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
PREMISE Shifts in abiotic factors can affect many plant traits, including floral volatiles. This study examined the response of floral volatiles to water availability and whether phenotypic plasticity to water availability differs among populations. It also investigated genetic differentiation in floral volatiles, determined the effect of temperature on phenotypic plasticity to water availability, and assessed temporal variation in floral scent emission between day and evening, since pollinator visitation differs at those times. METHODS Rocky Mountain columbine plants (Aquilegia coerulea), started from seeds collected in three wild populations in Colorado, Utah, and Arizona, were grown under two water treatments in a greenhouse in Madison, Wisconsin, United States. One population was also grown under the two water treatments, at two temperatures. Air samples were collected from enclosed flowers using dynamic headspace methods and floral volatiles were identified and quantified by gas chromatography (GC) with mass spectrometry (MS). RESULTS Emission of three floral volatiles increased in the wetter environment, indicating phenotypic plasticity. The response of six floral volatiles to water availability differed among populations, suggesting genetic differentiation in phenotypic plasticity. Five floral volatiles varied among populations, and emission of most floral volatiles was greater during the day. CONCLUSIONS Phenotypic plasticity to water availability permits a quick response of floral volatiles in changing environments. The genetic differentiation in phenotypic plasticity suggests that phenotypic plasticity can evolve but complicates predictions of the effects of environmental changes on a plant and its pollinators.
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Affiliation(s)
- Ken Keefover-Ring
- Departments of Botany and Geography, University of Wisconsin-Madison, Madison, 53706, WI, USA
| | | | - Johanne Brunet
- Vegetable Crops Research Unit, United States Department of Agriculture, Agricultural Research Service, Madison, 53706, WI, USA
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8
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Campbell DR, Bischoff M, Raguso RA, Briggs HM, Sosenski P. Selection of Floral Traits by Pollinators and Seed Predators during Sequential Life History Stages. Am Nat 2022; 199:808-823. [DOI: 10.1086/716740] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Diane R. Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
| | - Mascha Bischoff
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
- Environmental Research Institute, North Highland College, Castle Street, Thurso KW14 7JD, United Kingdom
| | - Robert A. Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
| | - Heather M. Briggs
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
| | - Paula Sosenski
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92617
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado 81224
- Consejo Nacional de Ciencia y Tecnología (CONACYT)–Departamento de Ecología Tropical, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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9
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Mostafa S, Wang Y, Zeng W, Jin B. Floral Scents and Fruit Aromas: Functions, Compositions, Biosynthesis, and Regulation. FRONTIERS IN PLANT SCIENCE 2022; 13:860157. [PMID: 35360336 PMCID: PMC8961363 DOI: 10.3389/fpls.2022.860157] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 02/09/2022] [Indexed: 05/27/2023]
Abstract
Floral scents and fruit aromas are crucial volatile organic compounds (VOCs) in plants. They are used in defense mechanisms, along with mechanisms to attract pollinators and seed dispersers. In addition, they are economically important for the quality of crops, as well as quality in the perfume, cosmetics, food, drink, and pharmaceutical industries. Floral scents and fruit aromas share many volatile organic compounds in flowers and fruits. Volatile compounds are classified as terpenoids, phenylpropanoids/benzenoids, fatty acid derivatives, and amino acid derivatives. Many genes and transcription factors regulating the synthesis of volatiles have been discovered. In this review, we summarize recent progress in volatile function, composition, biosynthetic pathway, and metabolism regulation. We also discuss unresolved issues and research perspectives, providing insight into improvements and applications of plant VOCs.
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Affiliation(s)
- Salma Mostafa
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Department of Floriculture, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
| | - Yun Wang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Wen Zeng
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Biao Jin
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
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10
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Bechen LL, Johnson MG, Broadhead GT, Levin RA, Overson RP, Jogesh T, Fant JB, Raguso RA, Skogen KA, Wickett NJ. Differential gene expression associated with a floral scent polymorphism in the evening primrose Oenothera harringtonii (Onagraceae). BMC Genomics 2022; 23:124. [PMID: 35151274 PMCID: PMC8840323 DOI: 10.1186/s12864-022-08370-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 12/30/2021] [Indexed: 12/13/2022] Open
Abstract
Background Plant volatiles play an important role in both plant-pollinator and plant-herbivore interactions. Intraspecific polymorphisms in volatile production are ubiquitous, but studies that explore underlying differential gene expression are rare. Oenothera harringtonii populations are polymorphic in floral emission of the monoterpene (R)-(−)-linalool; some plants emit (R)-(−)-linalool (linalool+ plants) while others do not (linalool- plants). However, the genes associated with differential production of this floral volatile in Oenothera are unknown. We used RNA-Seq to broadly characterize differential gene expression involved in (R)-(−)-linalool biosynthesis. To identify genes that may be associated with the polymorphism for this trait, we used RNA-Seq to compare gene expression in six different Oenothera harringtonii tissues from each of three linalool+ and linalool- plants. Results Three clusters of differentially expressed genes were enriched for terpene synthase activity: two were characterized by tissue-specific upregulation and one by upregulation only in plants with flowers that produce (R)-(−)-linalool. A molecular phylogeny of all terpene synthases identified two putative (R)-(−)-linalool synthase transcripts in Oenothera harringtonii, a single allele of which is found exclusively in linalool+ plants. Conclusions By using a naturally occurring polymorphism and comparing different tissues, we were able to identify candidate genes putatively involved in the biosynthesis of (R)-(−)-linalool. Expression of these genes in linalool- plants, while low, suggests a regulatory polymorphism, rather than a population-specific loss-of-function allele. Additional terpene biosynthesis-related genes that are up-regulated in plants that emit (R)-(−)-linalool may be associated with herbivore defense, suggesting a potential economy of scale between plant reproduction and defense. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08370-6.
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11
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Manincor N, Andreu B, Buatois B, Lou Chao H, Hautekèete N, Massol F, Piquot Y, Schatz B, Schmitt E, Dufay M. Geographical variation of floral scents in generalist entomophilous species with variable pollinator communities. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Benjamin Andreu
- CEFE Univ. Montpellier CNRS EPHE IRD Univ. Paul Valéry Montpellier 3 Montpellier France
| | - Bruno Buatois
- CEFE Univ. Montpellier CNRS EPHE IRD Univ. Paul Valéry Montpellier 3 Montpellier France
| | | | | | - François Massol
- Univ. Lille CNRS UMR 8198—Evo‐Eco‐Paleo Lille France
- Univ. Lille CNRS Inserm CHU Lille Institut Pasteur de Lille U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille Lille France
| | - Yves Piquot
- Univ. Lille CNRS UMR 8198—Evo‐Eco‐Paleo Lille France
| | - Bertrand Schatz
- CEFE Univ. Montpellier CNRS EPHE IRD Univ. Paul Valéry Montpellier 3 Montpellier France
| | - Eric Schmitt
- Univ. Lille CNRS UMR 8198—Evo‐Eco‐Paleo Lille France
| | - Mathilde Dufay
- Univ. Lille CNRS UMR 8198—Evo‐Eco‐Paleo Lille France
- CEFE Univ. Montpellier CNRS EPHE IRD Univ. Paul Valéry Montpellier 3 Montpellier France
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12
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Gfrerer E, Laina D, Gibernau M, Fuchs R, Happ M, Tolasch T, Trutschnig W, Hörger AC, Comes HP, Dötterl S. Floral Scents of a Deceptive Plant Are Hyperdiverse and Under Population-Specific Phenotypic Selection. FRONTIERS IN PLANT SCIENCE 2021; 12:719092. [PMID: 34630465 PMCID: PMC8500232 DOI: 10.3389/fpls.2021.719092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Floral scent is a key mediator in plant-pollinator interactions. However, little is known to what extent intraspecific scent variation is shaped by phenotypic selection, with no information yet in deceptive plants. In this study, we collected inflorescence scent and fruit set of the deceptive moth fly-pollinated Arum maculatum L. (Araceae) from six populations north vs. five populations south of the Alps, accumulating to 233 samples in total, and tested for differences in scent, fruit set, and phenotypic selection on scent across this geographic barrier. We recorded 289 scent compounds, the highest number so far reported in a single plant species. Most of the compounds occurred both north and south of the Alps; however, plants of the different regions emitted different absolute and relative amounts of scent. Fruit set was higher north than south of the Alps, and some, but not all differences in scent could be explained by differential phenotypic selection in northern vs. southern populations. This study is the first to provide evidence that floral scents of a deceptive plant are under phenotypic selection and that phenotypic selection is involved in shaping geographic patterns of floral scent in such plants. The hyperdiverse scent of A. maculatum might result from the imitation of various brood substrates of its pollinators.
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Affiliation(s)
- Eva Gfrerer
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Danae Laina
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Marc Gibernau
- Laboratory of Sciences for the Environment, CNRS – University of Corsica, Ajaccio, France
| | - Roman Fuchs
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Martin Happ
- Lab for Intelligent Data Analytics Salzburg, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Till Tolasch
- FG Tierökologie, University of Hohenheim, Stuttgart, Germany
| | - Wolfgang Trutschnig
- Department of Mathematics, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Anja C. Hörger
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Hans Peter Comes
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Stefan Dötterl
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
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13
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van der Kooi CJ, Vallejo-Marín M, Leonhardt SD. Mutualisms and (A)symmetry in Plant-Pollinator Interactions. Curr Biol 2021; 31:R91-R99. [PMID: 33497641 DOI: 10.1016/j.cub.2020.11.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The majority of flowering plants relies on animal pollinators for sexual reproduction and many animal pollinators rely on floral resources. However, interests of plants and pollinators are often not the same, resulting in an asymmetric relationship that ranges from mutualistic to parasitic interactions. Our understanding of the processes that underlie this asymmetry remains fragmentary. In this Review, we bring together evidence from evolutionary biology, plant chemistry, biomechanics, sensory ecology and behaviour to illustrate that the degree of symmetry often depends on the perspective taken. We also highlight variation in (a)symmetry within and between plant and pollinator species as well as between geographic locations. Through taking different perspectives from the plant and pollinator sides we provide new ground for studies on the maintenance and evolution of animal pollination and on the (a)symmetry in plant-pollinator interactions.
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Affiliation(s)
- Casper J van der Kooi
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands.
| | | | - Sara D Leonhardt
- Department of Ecology and Ecosystem Management, Technical University of Munich, Freising, Germany
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14
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Cna'ani A, Dener E, Ben-Zeev E, Günther J, Köllner TG, Tzin V, Seifan M. Phylogeny and abiotic conditions shape the diel floral emission patterns of desert Brassicaceae species. PLANT, CELL & ENVIRONMENT 2021; 44:2656-2671. [PMID: 33715174 DOI: 10.1111/pce.14045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
A key facet of floral scent is diel fluctuations in emission, often studied in the context of plant-pollinator interactions, while contributions of environment and phylogeny remain overlooked. Here, we ask if these factors are involved in shaping temporal variations in scent emission. To that end, we coupled light/dark floral emission measurements of 17 desert Brassicaceae species with environmental and phylogenetic data to explore the individual/combined impacts of these predictors on diel emission patterns. We further investigated these patterns by conducting high-resolution emission measurements in a subset of genetically distant species with contrasting temporal dynamics. While diel shifts in magnitude and richness of emission were strongly affected by genetic relatedness, they also reflect the environmental conditions under which the species grow. Specifically, light/dark emission ratios were negatively affected by an increase in winter temperatures, known to impact both plant physiology and insect locomotion, and sandy soil fractions, previously shown to exert stress that tempers with diel metabolic rhythms. Additionally, the biosynthetic origins of the compounds were associated with their corresponding production patterns, possibly to maximize emission efficacy. Using a multidisciplinary chemical/ecological approach, we uncover and differentiate the main factors shaping floral scent diel fluctuations, highlighting their consequences under changing global climate.
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Affiliation(s)
- Alon Cna'ani
- Jacob Blaustein Center for Scientific Cooperation, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Midreshet Ban-Gurion, Israel
| | - Efrat Dener
- The Albert Katz International School for Desert Studies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Midreshet Ban-Gurion, Israel
| | - Efrat Ben-Zeev
- Nancy and Stephen Grand Israel National Center for Personalized Medicine, The Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Jan Günther
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena, Germany
- Section of Plant Biochemistry, Department of Plant and Environmental Science, University of Copenhagen, Copenhagen, Denmark
| | - Tobias G Köllner
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Vered Tzin
- French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Midreshet Ban-Gurion, Israel
| | - Merav Seifan
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Midreshet Ban-Gurion, Israel
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15
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Trunschke J, Lunau K, Pyke GH, Ren ZX, Wang H. Flower Color Evolution and the Evidence of Pollinator-Mediated Selection. FRONTIERS IN PLANT SCIENCE 2021; 12:617851. [PMID: 34381464 PMCID: PMC8350172 DOI: 10.3389/fpls.2021.617851] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 05/14/2021] [Indexed: 06/01/2023]
Abstract
The evolution of floral traits in animal-pollinated plants involves the interaction between flowers as signal senders and pollinators as signal receivers. Flower colors are very diverse, effect pollinator attraction and flower foraging behavior, and are hypothesized to be shaped through pollinator-mediated selection. However, most of our current understanding of flower color evolution arises from variation between discrete color morphs and completed color shifts accompanying pollinator shifts, while evidence for pollinator-mediated selection on continuous variation in flower colors within populations is still scarce. In this review, we summarize experiments quantifying selection on continuous flower color variation in natural plant populations in the context of pollinator interactions. We found that evidence for significant pollinator-mediated selection is surprisingly limited among existing studies. We propose several possible explanations related to the complexity in the interaction between the colors of flowers and the sensory and cognitive abilities of pollinators as well as pollinator behavioral responses, on the one hand, and the distribution of variation in color phenotypes and fitness, on the other hand. We emphasize currently persisting weaknesses in experimental procedures, and provide some suggestions for how to improve methodology. In conclusion, we encourage future research to bring together plant and animal scientists to jointly forward our understanding of the mechanisms and circumstances of pollinator-mediated selection on flower color.
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Affiliation(s)
- Judith Trunschke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Klaus Lunau
- Institute of Sensory Ecology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Graham H. Pyke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Department of Biological Sciences, Macquarie University, Ryde, NSW, Australia
| | - Zong-Xin Ren
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
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Moré M, Soteras F, Ibañez AC, Dötterl S, Cocucci AA, Raguso RA. Floral Scent Evolution in the Genus Jaborosa (Solanaceae): Influence of Ecological and Environmental Factors. PLANTS (BASEL, SWITZERLAND) 2021; 10:1512. [PMID: 34451557 PMCID: PMC8398055 DOI: 10.3390/plants10081512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/05/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Floral scent is a key communication channel between plants and pollinators. However, the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a 'warm Lowland Subtropical nectar-rewarding clade' with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a 'cool-temperate brood-deceptive clade' of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across "pollinator climates" (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.
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Affiliation(s)
- Marcela Moré
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Florencia Soteras
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Ana C. Ibañez
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Stefan Dötterl
- Department of Biosciences, Paris-Lodron-University of Salzburg, 5020 Salzburg, Austria;
| | - Andrea A. Cocucci
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Robert A. Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
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Bing J, Li X, Haverkamp A, Baldwin IT, Hansson BS, Knaden M, Yon F. Variation in Manduca sexta Pollination-Related Floral Traits and Reproduction in a Wild Tobacco Plant. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.680463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Most flowering plants depend on animal pollination for successful sexual reproduction. Floral signals such as color, shape, and odor are crucial in establishing this (often mutualistic) interaction. Plant and pollinator phenotypes can vary temporally but also spatially, thus creating mosaic-like patterns of local adaptations. Here, we investigated natural variation in floral morphology, flower volatile emission, and phenology in four accessions of a self-compatible wild tobacco, Nicotiana attenuata, to assess how these traits match the sensory perception of a known pollinator, the hawkmoth Manduca sexta. These accessions differ in floral traits and also in their habitat altitudes. Based on habitat temperatures, the accession occurring at the highest altitude (California) is less likely to be visited by M. sexta, while the others (Arizona, Utah 1, and Utah 2) are known to receive M. sexta pollinations. The accessions varied significantly in flower morphologies, volatile emissions, flower opening, and phenology, traits likely important for M. sexta perception and floral handling. In wind tunnel assays, we assessed the seed set of emasculated flowers after M. sexta visitation and of natural selfed and hand-pollinated selfed flowers. After moth visitations, plants of two accessions (Arizona and Utah 2) produced more capsules than the other two, consistent with predictions that accessions co-occurring with M. sexta would benefit more from the pollination services of this moth. We quantified flower and capsule production in four accessions in a glasshouse assay without pollinators to assess the potential for self-pollination. The two Utah accessions set significantly more seeds after pollen supplementation compared with those of autonomous selfing flowers, suggesting a greater opportunistic benefit from efficient pollinators than the other two. Moreover, emasculated flowers of the accession with the most exposed stigma (Utah 2) produced the greatest seed set after M. sexta visitation. This study reveals intraspecific variation in pollination syndromes that illuminate the potential of a plant species to adapt to local pollinator communities, changing environments, and altered pollination networks.
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Luizzi VJ, Friberg M, Petrén H. Phenotypic plasticity in floral scent in response to nutrient, but not water, availability in the perennial plant
Arabis alpina. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13866] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Victoria J. Luizzi
- Department of Ecology & Evolutionary Biology University of Arizona Tucson AZ USA
- Department of Biology Lund University Lund Sweden
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19
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Szenteczki MA, Godschalx AL, Galmán A, Espíndola A, Gibernau M, Alvarez N, Rasmann S. Spatial and temporal heterogeneity in pollinator communities maintains within‐species floral odour variation. OIKOS 2021. [DOI: 10.1111/oik.08445] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Andrea Galmán
- Misión Biológica de Galicia (MBG‐CSIC), Pontevedra Galicia Spain
| | | | - Marc Gibernau
- CNRS – Univ. of Corsica, Laboratory Sciences for the Environment (SPE – UMR 6134), Natural Resources Project Ajaccio France
| | - Nadir Alvarez
- Geneva Natural History Museum Genève Switzerland
- Dept of Genetics and Evolution, Univ. of Geneva Geneva Switzerland
| | - Sergio Rasmann
- Inst. de Biologie, Univ. de Neuchâtel Neuchâtel Switzerland
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20
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Ohashi K, Jürgens A, Thomson JD. Trade-off mitigation: a conceptual framework for understanding floral adaptation in multispecies interactions. Biol Rev Camb Philos Soc 2021; 96:2258-2280. [PMID: 34096158 PMCID: PMC8518848 DOI: 10.1111/brv.12754] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 11/26/2022]
Abstract
Explanations of floral adaptation to diverse pollinator faunas have often invoked visitor‐mediated trade‐offs in which no intermediate, generalized floral phenotype is optimal for pollination success, i.e. fitness valleys are created. In such cases, plant species are expected to specialize on particular groups of flower visitors. Contrary to this expectation, it is commonly observed that flowers interact with various groups of visitors, while at the same time maintaining distinct phenotypes among ecotypes, subspecies, or congeners. This apparent paradox may be due to a gap in our understanding of how visitor‐mediated trade‐offs could affect floral adaptation. Here we provide a conceptual framework for analysing visitor‐mediated trade‐offs with the hope of stimulating empirical and theoretical studies to fill this gap. We propose two types of visitor‐mediated trade‐offs to address negative correlations among fitness contributions of different visitors: visitor‐mediated phenotypic trade‐offs (phenotypic trade‐offs) and visitor‐mediated opportunity trade‐offs (opportunity trade‐offs). Phenotypic trade‐offs occur when different groups of visitors impose conflicting selection pressures on a floral trait. By contrast, opportunity trade‐offs emerge only when some visitors’ actions (e.g. pollen collection) remove opportunities for fitness contribution by more beneficial visitors. Previous studies have observed disruptive selection due to phenotypic trade‐offs less often than expected. In addition to existing explanations, we propose that some flowers have achieved ‘adaptive generalization’ by evolving features to avoid or eliminate the fitness valleys that phenotypic trade‐offs tend to produce. The literature suggests a variety of pathways to such ‘trade‐off mitigation’. Trade‐off mitigation may also evolve as an adaptation to opportunity trade‐offs. We argue that active exclusion, or floral specialization, can be viewed as a trade‐off mitigation, occurring only when flowers cannot otherwise avoid strong opportunity trade‐offs. These considerations suggest that an evolutionary strategy for trade‐off mitigation is achieved often by acquiring novel combinations of traits. Thus, phenotypic diversification of flowers through convergent evolution of certain trait combinations may have been enhanced not only through adaptive specialization for particular visitors, but also through adaptive generalization for particular visitor communities. Explorations of how visitor‐mediated trade‐offs explain the recurrent patterns of floral phenotypes may help reconcile the long‐lasting controversy on the validity of pollination syndromes.
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Affiliation(s)
- Kazuharu Ohashi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.,Department of Biology, Chemical Plant Ecology, Technische Universität Darmstadt, Schnittspahnstrasse 4, 64287 Darmstadt, Germany
| | - Andreas Jürgens
- Department of Biology, Chemical Plant Ecology, Technische Universität Darmstadt, Schnittspahnstrasse 4, 64287 Darmstadt, Germany
| | - James D Thomson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., Toronto, ON, M5S 3G5, Canada
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21
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Eisen KE, Geber MA, Raguso RA. Emission rates of species-specific volatiles vary across communities of Clarkia species: Evidence for multi-modal character displacement. Am Nat 2021; 199:824-840. [DOI: 10.1086/715501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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22
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Petrén H, Toräng P, Ågren J, Friberg M. Evolution of floral scent in relation to self-incompatibility and capacity for autonomous self-pollination in the perennial herb Arabis alpina. ANNALS OF BOTANY 2021; 127:737-747. [PMID: 33555338 PMCID: PMC8103803 DOI: 10.1093/aob/mcab007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS The transition from outcrossing to selfing is a frequent evolutionary shift in flowering plants and is predicted to result in reduced allocation to pollinator attraction if plants can self-pollinate autonomously. The evolution of selfing is associated with reduced visual floral signalling in many systems, but effects on floral scent have received less attention. We compared multiple populations of the arctic-alpine herb Arabis alpina (Brassicaceae), and asked whether the transition from self-incompatibility to self-compatibility has been associated with reduced visual and chemical floral signalling. We further examined whether floral signalling differ between self-compatible populations with low and high capacity for autonomous self-pollination, as would be expected if benefits of signalling decrease with reduced dependence on pollinators for pollen transfer. METHODS In a common garden we documented flower size and floral scent emission rate and composition in eight self-compatible and nine self-incompatible A. alpina populations. These included self-compatible Scandinavian populations with high capacity for autonomous self-pollination, self-compatible populations with low capacity for autonomous self-pollination from France and Spain, and self-incompatible populations from Italy and Greece. KEY RESULTS The self-compatible populations produced smaller and less scented flowers than the self-incompatible populations. However, flower size and scent emission rate did not differ between self-compatible populations with high and low capacity for autonomous self-pollination. Floral scent composition differed between self-compatible and self-incompatible populations, but also varied substantially among populations within the two categories. CONCLUSIONS Our study demonstrates extensive variation in floral scent among populations of a geographically widespread species. Contrary to expectation, floral signalling did not differ between self-compatible populations with high and low capacity for autonomous self-pollination, indicating that dependence on pollinator attraction can only partly explain variation in floral signalling. Additional variation may reflect adaptation to other aspects of local environments, genetic drift, or a combination of these processes.
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Affiliation(s)
- Hampus Petrén
- Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Per Toräng
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
- SLU Swedish Species Information Centre, Box 7007, SE-750 07 Uppsala, Sweden
| | - Jon Ågren
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Magne Friberg
- Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
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23
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Orsucci M, Sicard A. Flower evolution in the presence of heterospecific gene flow and its contribution to lineage divergence. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:971-989. [PMID: 33537708 DOI: 10.1093/jxb/eraa549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The success of species depends on their ability to exploit ecological resources in order to optimize their reproduction. However, species are not usually found within single-species ecosystems but in complex communities. Because of their genetic relatedness, closely related lineages tend to cluster within the same ecosystem, rely on the same resources, and be phenotypically similar. In sympatry, they will therefore compete for the same resources and, in the case of flowering plants, exchange their genes through heterospecific pollen transfer. These interactions, nevertheless, pose significant challenges to species co-existence because they can lead to resource limitation and reproductive interference. In such cases, divergent selective pressures on floral traits will favour genotypes that isolate or desynchronize the reproduction of sympatric lineages. The resulting displacement of reproductive characters will, in turn, lead to pre-mating isolation and promote intraspecific divergence, thus initiating or reinforcing the speciation process. In this review, we discuss the current theoretical and empirical knowledge on the influence of heterospecific pollen transfer on flower evolution, highlighting its potential to uncover the ecological and genomic constraints shaping the speciation process.
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Affiliation(s)
- Marion Orsucci
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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24
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Zu P, Schiestl FP, Gervasi D, Li X, Runcie D, Guillaume F. Floral signals evolve in a predictable way under artificial and pollinator selection in Brassica rapa. BMC Evol Biol 2020; 20:127. [PMID: 32972368 PMCID: PMC7517814 DOI: 10.1186/s12862-020-01692-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 09/16/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Angiosperms employ an astonishing variety of visual and olfactory floral signals that are generally thought to evolve under natural selection. Those morphological and chemical traits can form highly correlated sets of traits. It is not always clear which of these are used by pollinators as primary targets of selection and which would be indirectly selected by being linked to those primary targets. Quantitative genetics tools for predicting multiple traits response to selection have been developed since long and have advanced our understanding of evolution of genetically correlated traits in various biological systems. We use these tools to predict the evolutionary trajectories of floral traits and understand the selection pressures acting on them. RESULTS We used data from an artificial selection and a pollinator (bumblebee, hoverfly) evolution experiment with fast cycling Brassica rapa plants to predict evolutionary changes of 12 floral volatiles and 4 morphological floral traits in response to selection. Using the observed selection gradients and the genetic variance-covariance matrix (G-matrix) of the traits, we showed that the observed responses of most floral traits including volatiles were predicted in the right direction in both artificial- and bumblebee-selection experiment. Genetic covariance had a mix of constraining and facilitating effects on evolutionary responses. We further revealed that G-matrices also evolved in the selection processes. CONCLUSIONS Overall, our integrative study shows that floral signals, especially volatiles, evolve under selection in a mostly predictable way, at least during short term evolution. Evolutionary constraints stemming from genetic covariance affected traits evolutionary trajectories and thus it is important to include genetic covariance for predicting the evolutionary changes of a comprehensive suite of traits. Other processes such as resource limitation and selfing also need to be considered for a better understanding of floral trait evolution.
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Affiliation(s)
- Pengjuan Zu
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
| | - Daniel Gervasi
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland
| | - Xin Li
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Daniel Runcie
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Frédéric Guillaume
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
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25
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Joffard N, Arnal V, Buatois B, Schatz B, Montgelard C. Floral scent evolution in the section Pseudophrys: pollinator-mediated selection or phylogenetic constraints? PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:881-889. [PMID: 32130747 DOI: 10.1111/plb.13104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 02/07/2020] [Indexed: 06/10/2023]
Abstract
Sexually deceptive orchid species from the Mediterranean genus Ophrys usually interact with one or a few pollinator species by means of specific floral scents. In this study, we investigated the respective role of pollinator-mediated selection and phylogenetic constraints in the evolution of floral scents in the section Pseudophrys. We built a phylogenetic tree of 19 Pseudophrys species based on three nuclear loci; we gathered a dataset on their pollination interactions from the literature and from our own field data; and we extracted and analysed their floral scents using solid phase microextraction and gas chromatography-mass spectrometry. We then quantified the phylogenetic signal carried by floral scents and investigated the link between plant-pollinator interactions and floral scent composition using phylogenetic comparative methods. We confirmed the monophyly of the section Pseudophrys and demonstrated the existence of three main clades within this section. We found that floral scent composition is affected by both phylogenetic relationships among Ophrys species and pollination interactions, with some compounds (especially fatty acid esters) carrying a significant phylogenetic signal and some (especially alkenes and alkadienes) generating dissimilarities between closely related Pseudophrys pollinated by different insects. Our results show that in the section Pseudophrys, floral scents are shaped both by pollinator-mediated selection and by phylogenetic constraints, but that the relative importance of these two evolutionary forces differ among compound classes, probably reflecting distinct selective pressures imposed upon behaviourally active and non-active compounds.
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Affiliation(s)
- N Joffard
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, Montpellier, France
| | - V Arnal
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, Montpellier, France
| | - B Buatois
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, Montpellier, France
| | - B Schatz
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, Montpellier, France
| | - C Montgelard
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry Montpellier - EPHE, Montpellier, France
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26
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Joffard N, Le Roncé I, Langlois A, Renoult J, Buatois B, Dormont L, Schatz B. Floral trait differentiation in Anacamptis coriophora: Phenotypic selection on scents, but not on colour. J Evol Biol 2020; 33:1028-1038. [PMID: 32500947 DOI: 10.1111/jeb.13657] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 05/14/2020] [Accepted: 05/23/2020] [Indexed: 01/26/2023]
Abstract
Current divergent selection may promote floral trait differentiation among conspecific populations in flowering plants. However, whether this applies to complex traits such as colour or scents has been little studied, even though these traits often vary within species. In this study, we compared floral colour and odour as well as selective pressures imposed upon these traits among seven populations belonging to three subspecies of the widespread, generalist orchid Anacamptis coriophora. Colour was characterized using calibrated photographs, and scents were sampled using dynamic headspace extraction and analysed using gas chromatography-mass spectrometry. We then quantified phenotypic selection exerted on these traits by regressing fruit set values on floral trait values. We showed that the three studied subspecies were characterized by different floral colour and odour, with one of the two predominant floral volatiles emitted by each subspecies being taxon-specific. Plant size was positively correlated with fruit set in most populations, whereas we found no apparent link between floral colour and female reproductive success. We detected positive selection on several taxon-specific compounds in A. coriophora subsp. fragrans, whereas no selection was found on floral volatiles of A. coriophora subsp. coriophora and A. coriophora subsp. martrinii. This study is one of the first to document variation in phenotypic selection exerted on floral scents among conspecific populations. Our results suggest that selection could contribute to ongoing chemical divergence among A. coriophora subspecies.
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Affiliation(s)
- Nina Joffard
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
- Evolutionsbiologiskt Centrum (EBC), Uppsala, Sweden
| | - Iris Le Roncé
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
- Département de biologie, École Normale Supérieure de Lyon, Lyon, France
| | - Alban Langlois
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
- Université Toulouse III Paul Sabatier, Toulouse, France
| | - Julien Renoult
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
| | - Bruno Buatois
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
| | - Laurent Dormont
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
| | - Bertrand Schatz
- Centre d'Ecologie Fonctionnelle et Evolutive, EPHE-PSL, CNRS, Univ. Montpellier, Univ. Paul Valéry Montpellier 3, IRD, Montpellier, France
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Chapurlat E, Le Roncé I, Ågren J, Sletvold N. Divergent selection on flowering phenology but not on floral morphology between two closely related orchids. Ecol Evol 2020; 10:5737-5747. [PMID: 32607187 PMCID: PMC7319237 DOI: 10.1002/ece3.6312] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/09/2020] [Accepted: 03/30/2020] [Indexed: 11/08/2022] Open
Abstract
Closely related species often differ in traits that influence reproductive success, suggesting that divergent selection on such traits contribute to the maintenance of species boundaries. Gymnadenia conopsea ss. and Gymnadenia densiflora are two closely related, perennial orchid species that differ in (a) floral traits important for pollination, including flowering phenology, floral display, and spur length, and (b) dominant pollinators. If plant-pollinator interactions contribute to the maintenance of trait differences between these two taxa, we expect current divergent selection on flowering phenology and floral morphology between the two species. We quantified phenotypic selection via female fitness in one year on flowering start, three floral display traits (plant height, number of flowers, and corolla size) and spur length, in six populations of G. conopsea s.s. and in four populations of G. densiflora. There was indication of divergent selection on flowering start in the expected direction, with selection for earlier flowering in two populations of the early-flowering G. conopsea s.s. and for later flowering in one population of the late-flowering G. densiflora. No divergent selection on floral morphology was detected, and there was no significant stabilizing selection on any trait in the two species. The results suggest ongoing adaptive differentiation of flowering phenology, strengthening this premating reproductive barrier between the two species. Synthesis: This study is among the first to test whether divergent selection on floral traits contribute to the maintenance of species differences between closely related plants. Phenological isolation confers a substantial potential for reproductive isolation, and divergent selection on flowering time can thus greatly influence reproductive isolation and adaptive differentiation.
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Affiliation(s)
- Elodie Chapurlat
- Plant Ecology and EvolutionDepartment of Ecology and GeneticsEvolutionary Biology CentreUppsala UniversityUppsalaSweden
| | - Iris Le Roncé
- Plant Ecology and EvolutionDepartment of Ecology and GeneticsEvolutionary Biology CentreUppsala UniversityUppsalaSweden
- Master BioSciencesÉcole Normale Supérieure de LyonUniversité Claude Bernard Lyon 1Université de LyonLyonFrance
| | - Jon Ågren
- Plant Ecology and EvolutionDepartment of Ecology and GeneticsEvolutionary Biology CentreUppsala UniversityUppsalaSweden
| | - Nina Sletvold
- Plant Ecology and EvolutionDepartment of Ecology and GeneticsEvolutionary Biology CentreUppsala UniversityUppsalaSweden
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Stephens RB, Trowbridge AM, Ouimette AP, Knighton WB, Hobbie EA, Stoy PC, Rowe RJ. Signaling from below: rodents select for deeper fruiting truffles with stronger volatile emissions. Ecology 2020; 101:e02964. [PMID: 31872867 DOI: 10.1002/ecy.2964] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/15/2019] [Accepted: 11/05/2019] [Indexed: 11/11/2022]
Abstract
Many plant and fungal species use volatile organic compounds (VOCs) as chemical signals to convey information about the location or quality of their fruits or fruiting bodies to animal dispersers. Identifying the environmental factors and biotic interactions that shape fruit selection by animals is key to understanding the evolutionary processes that underpin chemical signaling. Using four Elaphomyces truffle species, we explored the role of fruiting depth, VOC emissions, and protein content in selection by five rodent species. We used stable isotope analysis of nitrogen (δ15 N) in truffles to estimate fruiting depth, proton-transfer-reaction mass spectrometry to determine volatile emission composition, and nitrogen concentrations to calculate digestible protein of truffles. We coupled field surveys of truffle availability with truffle spore loads in rodent scat to determine selection by rodents. Despite presumably easier access to the shallow fruiting species, E. americanus (0.5-cm depth) and E. verruculosus (2.5-cm depth), most rodents selected for truffles fruiting deeper in the soil, E. macrosporus (4.1-cm depth) and E. bartlettii (5.0-cm depth). The deeper fruiting species had distinct VOC profiles and produced significantly higher quantities of odiferous compounds. Myodes gapperi (southern red-backed vole), a fungal specialist, also selected for truffles with high levels of digestible protein, E. verruculosus and E. macrosporus. Our results highlight the importance of chemical signals in truffle selection by rodents and suggest that VOCs are under strong selective pressures relative to protein rewards. Strong chemical signals likely allow detection of truffles deep within the soil and reduce foraging effort by rodents. For rodents that depend on fungi as a major food source, protein content may also be important in selecting truffles.
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Affiliation(s)
- Ryan B Stephens
- Natural Resources and the Environment, University of New Hampshire, 114 James Hall, 56 College Road, Durham, New Hampshire, 03824, USA
| | - Amy M Trowbridge
- Department of Entomology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Andrew P Ouimette
- Earth Systems Research Center, University of New Hampshire, Morse Hall, 8 College Road, Durham, New Hampshire, 03824, USA
| | - W Berk Knighton
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, 59717, USA
| | - Erik A Hobbie
- Earth Systems Research Center, University of New Hampshire, Morse Hall, 8 College Road, Durham, New Hampshire, 03824, USA
| | - Paul C Stoy
- Department of Biological Systems Engineering, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Rebecca J Rowe
- Natural Resources and the Environment, University of New Hampshire, 114 James Hall, 56 College Road, Durham, New Hampshire, 03824, USA
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30
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Is there spatial variation in phenotypic selection on floral traits in a generalist plant–pollinator system? Evol Ecol 2019. [DOI: 10.1007/s10682-019-10002-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Chapurlat E, Ågren J, Anderson J, Friberg M, Sletvold N. Conflicting selection on floral scent emission in the orchid Gymnadenia conopsea. THE NEW PHYTOLOGIST 2019; 222:2009-2022. [PMID: 30767233 DOI: 10.1111/nph.15747] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
Floral scent is a crucial trait for pollinator attraction. Yet only a handful of studies have estimated selection on scent in natural populations and no study has quantified the relative importance of pollinators and other agents of selection. In the fragrant orchid Gymnadenia conopsea, we used electroantennographic data to identify floral scent compounds detected by local pollinators and quantified pollinator-mediated selection on emission rates of 10 target compounds as well as on flowering start, visual display and spur length. Nocturnal pollinators contributed more to reproductive success than diurnal pollinators, but there was significant pollinator-mediated selection on both diurnal and nocturnal scent emission. Pollinators selected for increased emission of two compounds and reduced emission of two other compounds, none of which were major constituents of the total bouquet. In three cases, pollinator-mediated selection was opposed by nonpollinator-mediated selection, leading to weaker or no detectable net selection. Our study demonstrates that minor scent compounds can be targets of selection, that pollinators do not necessarily favour stronger scent signalling, and that some scent compounds are subject to conflicting selection from pollinators and other agents of selection. Hence, including floral scent traits into selection analysis is important for understanding the mechanisms behind floral evolution.
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Affiliation(s)
- Elodie Chapurlat
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Jon Ågren
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Joseph Anderson
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Magne Friberg
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
- Department of Biology, Lund University, SE-223 62, Lund, Sweden
| | - Nina Sletvold
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
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Flower scent of Ceropegia stenantha: electrophysiological activity and synthesis of novel components. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:301-310. [PMID: 30868226 PMCID: PMC6579769 DOI: 10.1007/s00359-019-01318-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 11/27/2022]
Abstract
In specialized pollination systems, floral scents are crucial for flower-pollinator communication, but key volatiles that attract pollinators are unknown for most systems. Deceptive Ceropegia trap flowers are famous for their elaborate mechanisms to trap flies. Recent studies revealed species-specific floral chemistry suggesting highly specialized mimicry strategies. However, volatiles involved in fly attraction were until now identified in C. dolichophylla and C. sandersonii, only. We here present data on C. stenantha for which flower scent and pollinators were recently described, but volatiles involved in flower-fly communication stayed unknown. We performed electrophysiological measurements with scatopsid fly pollinators (Coboldia fuscipes) and identified 12 out of 13 biologically active floral components. Among these volatiles some were never described from any organism but C. stenantha. We synthesized these components, tested them on antennae of male and female flies, and confirmed their biological activity. Overall, our data show that half of the volatiles emitted from C. stenantha flowers are perceived by male and female fly pollinators and are potentially important for flower-fly communication in this pollination system. Further studies are needed to clarify the role of the electrophysiologically active components in the life of scatopsid fly pollinators, and to fully understand the pollination strategy of C. stenantha.
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Extreme diversification of floral volatiles within and among species of Lithophragma (Saxifragaceae). Proc Natl Acad Sci U S A 2019; 116:4406-4415. [PMID: 30765532 DOI: 10.1073/pnas.1809007116] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
A major challenge in evolutionary biology is to understand how complex traits of multiple functions have diversified and codiversified across interacting lineages and geographic ranges. We evaluate intra- and interspecific variation in floral scent, which is a complex trait of documented importance for mutualistic and antagonistic interactions between plants, pollinators, and herbivores. We performed a large-scale, phylogenetically structured study of an entire plant genus (Lithophragma, Saxifragaceae), of which several species are coevolving with specialized pollinating floral parasites of the moth genus Greya (Prodoxidae). We sampled 94 Lithophragma populations distributed across all 12 recognized Lithophragma species and subspecies, and four populations of related saxifragaceous species. Our results reveal an unusually high diversity of floral volatiles among populations, species, and clades within the genus. Moreover, we found unexpectedly major changes at each of these levels in the biosynthetic pathways used by local populations in their floral scents. Finally, we detected significant, but variable, genus- and species-level patterns of ecological convergence in the floral scent signal, including an impact of the presence and absence of two pollinating Greya moth species. We propose that one potential key to understanding floral scent variation in this hypervariable genus is its geographically diverse interactions with the obligate specialized Greya moths and, in some species and sites, more generalized copollinators.
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Parachnowitsch AL, Manson JS, Sletvold N. Evolutionary ecology of nectar. ANNALS OF BOTANY 2019; 123:247-261. [PMID: 30032269 PMCID: PMC6344224 DOI: 10.1093/aob/mcy132] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/16/2018] [Indexed: 05/24/2023]
Abstract
Background Floral nectar is an important determinant of plant-pollinator interactions and an integral component of pollination syndromes, suggesting it is under pollinator-mediated selection. However, compared to floral display traits, we know little about the evolutionary ecology of nectar. Combining a literature review with a meta-analysis approach, we summarize the evidence for heritable variation in nectar traits and link this variation to pollinator response and plant fitness. We further review associations between nectar traits and floral signals and discuss them in the context of honest signalling and targets of selection. Scope Although nectar is strongly influenced by environmental factors, heritable variation in nectar production rate has been documented in several populations (mean h2 = 0.31). Almost nothing is known about heritability of other nectar traits, such as sugar and amino acid concentrations. Only a handful of studies have quantified selection on nectar traits, and few find statistically significant selection. Pollinator responses to nectar traits indicate they may drive selection, but studies tying pollinator preferences to plant fitness are lacking. So far, only one study conclusively identified pollinators as selective agents on a nectar trait, and the role of microbes, herbivores, nectar robbers and abiotic factors in nectar evolution is largely hypothetical. Finally, there is a trend for positive correlations among floral cues and nectar traits, indicating honest signalling of rewards. Conclusions Important progress can be made by studies that quantify current selection on nectar in natural populations, as well as experimental approaches that identify the target traits and selective agents involved. Signal-reward associations suggest that correlational selection may shape evolution of nectar traits, and studies exploring these more complex forms of natural selection are needed. Many questions about nectar evolution remain unanswered, making this a field ripe for future research.
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Affiliation(s)
- Amy L Parachnowitsch
- Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jessamyn S Manson
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Nina Sletvold
- Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
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35
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36
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Schiestl FP, Balmer A, Gervasi DD. Real‐time evolution supports a unique trajectory for generalized pollination*. Evolution 2018; 72:2653-2668. [DOI: 10.1111/evo.13611] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 08/13/2018] [Accepted: 09/05/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Florian P. Schiestl
- Institute of Systematic and Evolutionary BotanyUniversity of Zürich Zollikerstrasse 107, CH‐8008 Zürich Switzerland
| | - Alice Balmer
- Institute of Systematic and Evolutionary BotanyUniversity of Zürich Zollikerstrasse 107, CH‐8008 Zürich Switzerland
| | - Daniel D. Gervasi
- Institute of Systematic and Evolutionary BotanyUniversity of Zürich Zollikerstrasse 107, CH‐8008 Zürich Switzerland
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Crab spiders impact floral-signal evolution indirectly through removal of florivores. Nat Commun 2018; 9:1367. [PMID: 29636464 PMCID: PMC5893632 DOI: 10.1038/s41467-018-03792-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 03/13/2018] [Indexed: 02/05/2023] Open
Abstract
The puzzling diversity of flowers is primarily shaped by selection and evolutionary change caused by the plant's interaction with animals. The contribution of individual animal species to net selection, however, may vary depending on the network of interacting organisms. Here we document that in the buckler mustard, Biscutella laevigata, the crab spider Thomisus onustus reduces bee visits to flowers but also benefits plants by feeding on florivores. Uninfested plants experience a trade-off between pollinator and spider attraction as both bees and crab spiders are attracted by the floral volatile β-ocimene. This trade-off is reduced by the induced emission of β-ocimene after florivore infestation, which is stronger in plant populations where crab spiders are present than where they are absent, suggesting that plants are locally adapted to the presence of crab spiders. Our study demonstrates the context-dependence of selection and shows how crab spiders impact on floral evolution.
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38
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Weber MG, Cacho NI, Phan MJQ, Disbrow C, Ramírez SR, Strauss SY. The evolution of floral signals in relation to range overlap in a clade of California Jewelflowers (Streptanthus s.l.). Evolution 2018; 72:798-807. [PMID: 29464694 DOI: 10.1111/evo.13456] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/05/2018] [Accepted: 02/06/2018] [Indexed: 01/18/2023]
Abstract
Because of their function as reproductive signals in plants, floral traits experience distinct selective pressures related to their role in speciation, reinforcement, and prolonged coexistence with close relatives. However, few studies have investigated whether population-level processes translate into detectable signatures at the macroevolutionary scale. Here, we ask whether patterns of floral trait evolution and range overlap across a clade of California Jewelflowers reflect processes hypothesized to shape floral signal differentiation at the population level. We found a pattern of divergence in floral scent composition across the clade such that close relatives had highly disparate floral scents given their age. Accounting for range overlap with close relatives explained additional variation in floral scent over time, with sympatric species pairs having diverged more than allopatric species pairs given their age. However, three other floral traits (flower size, scent complexity and flower color) did not fit these patterns, failing to deviate from a null Brownian motion model of evolution. Together, our results suggest that selection for divergence among close relatives in the composition of floral scents may play a key, sustained role in mediating speciation and coexistence dynamics across this group, and that signatures of these dynamics may persist at the macroevolutionary scale.
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Affiliation(s)
- Marjorie G Weber
- Center for Population Biology, University of California, Davis, California 95616.,Current Address: Department of Plant Biology and Ecology, Evolutionary Biology and Behavior Program, Michigan State University, East Lansing, Michigan 48823
| | - N Ivalú Cacho
- Instituto de Biología, Universidad Nacional Autónoma de México, CDMX 04510, México.,Department of Evolution and Ecology, University of California, Davis, California 95616
| | - Martin J Q Phan
- Department of Evolution and Ecology, University of California, Davis, California 95616
| | - Caprice Disbrow
- Department of Evolution and Ecology, University of California, Davis, California 95616
| | - Santiago R Ramírez
- Center for Population Biology, University of California, Davis, California 95616.,Department of Evolution and Ecology, University of California, Davis, California 95616
| | - Sharon Y Strauss
- Center for Population Biology, University of California, Davis, California 95616.,Department of Evolution and Ecology, University of California, Davis, California 95616
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Chapurlat E, Anderson J, Ågren J, Friberg M, Sletvold N. Diel pattern of floral scent emission matches the relative importance of diurnal and nocturnal pollinators in populations of Gymnadenia conopsea. ANNALS OF BOTANY 2018; 121:711-721. [PMID: 29360931 PMCID: PMC5853007 DOI: 10.1093/aob/mcx203] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS Floral scent is considered an integral component of pollination syndromes, and its composition and timing of emission are thus expected to match the main pollinator type and time of activity. While floral scent differences among plant species with different pollination systems can be striking, studies on intraspecific variation are sparse, which limits our understanding of the role of pollinators in driving scent divergence. METHODS Here, we used dynamic headspace sampling to quantify floral scent emission and composition during the day and at night in the natural habitat of six Scandinavian populations of the fragrant orchid Gymnadenia conopsea. We tested whether diel scent emission and composition match pollinator type by comparing four populations in southern Sweden, where nocturnal pollinators are more important for plant reproductive success than are diurnal pollinators, with two populations in central Norway, where the opposite is true. To determine to what extent scent patterns quantified in the field reflected plasticity, we also measured scent emission in a common growth chamber environment. KEY RESULTS Both scent composition and emission rates differed markedly between day and night, but only the latter varied significantly among populations. The increase in scent emission rate at night was considerably stronger in the Swedish populations compared with the Norwegian populations. These patterns persisted when plants were transferred to a common environment, suggesting a genetic underpinning of the scent variation. CONCLUSIONS The results are consistent with a scenario where spatial variation in relative importance of nocturnal and diurnal pollinators has resulted in selection for different scent emission rhythms. Our study highlights the importance of adding a characterization of diel variation of scent emission rates to comparative studies of floral scent, which so far have often focused on scent composition only.
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Affiliation(s)
- Elodie Chapurlat
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Sweden
- For correspondence. E-mail
| | - Joseph Anderson
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Sweden
| | - Jon Ågren
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Sweden
| | - Magne Friberg
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Sweden
| | - Nina Sletvold
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Sweden
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40
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Ray HA, Stuhl CJ, Gillett-Kaufman JL. Floral fragrance analysis of Prosthechea cochleata (Orchidaceae), an endangered native, epiphytic orchid, in Florida. PLANT SIGNALING & BEHAVIOR 2018; 13:e1422461. [PMID: 29297748 PMCID: PMC5790404 DOI: 10.1080/15592324.2017.1422461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/01/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
South Florida is home to a number of native species of orchids. The Florida Panther National Wildlife Refuge has 27 known species, including Prosthechea cochleata, the clamshell orchid, which is listed as endangered on Florida's Regulated Plant Index. In a prior study done on this species in Mexico, P. cochleata was found to produce no floral fragrance at the particular study location. However, blooming orchids of this species at the University of Florida in Gainesville, were noted to be fragrant. In this paper, we document the presence of floral fragrance compounds from P. cochleata by using by gas chromatography mass spectrometry (GC/MS) analysis of headspace volatile collection. The orchids sampled were found to be consistently producing eight volatiles that are common in floral fragrances, including those of previous orchid species studied. By knowing the fragrance compounds produced, we can better understand the pollination biology of this endangered orchid. This information could be used to help future conservation efforts for P. cochelata by increasing pollination and subsequent seed capsule production.
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Affiliation(s)
- Haleigh A. Ray
- 1881 Natural Area Drive, Steinmetz Hall, Entomology and Nematology Department, University of Florida, Gainesville, FL
| | - Charles J. Stuhl
- Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service U.S. Department of Agriculture, Gainesville, FL
| | - Jennifer L. Gillett-Kaufman
- 1881 Natural Area Drive, Steinmetz Hall, Entomology and Nematology Department, University of Florida, Gainesville, FL
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Friberg M, Waters MT, Thompson JN. Nutrient availability affects floral scent much less than other floral and vegetative traits in Lithophragma bolanderi. ANNALS OF BOTANY 2017; 120:471-478. [PMID: 28655187 PMCID: PMC5591434 DOI: 10.1093/aob/mcx069] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 01/09/2017] [Indexed: 05/29/2023]
Abstract
Background and Aims Many plant-pollinator interactions are mediated by floral scents that can vary among species, among populations within species and even among individuals within populations. This variation could be innate and unaffected by the environment, but, because many floral volatiles have amino-acid precursors, scent variation also could be affected by differences in nutrient availability among environments. In plants that have coevolved with specific pollinators, natural selection is likely to favour low phenotypic plasticity in floral scent even under different conditions of nutrient availability if particular scents or scent combinations are important for attracting local pollinators. Methods Clonal pairs of multiple seed-families of two Lithophragma bolanderi (Saxifragaceae) populations were subjected to a high and a low nutrient treatment. These plants are pollinated primarily by host-specific Greya moths. It was evaluated how nutrient treatment affected variation in floral scent relative to other vegetative and reproductive traits. Key Results Floral scent strength (the per-flower emission rate) and composition were unaffected by nutrient treatment, but low-nutrient plants produced fewer and lighter leaves, fewer scapes and fewer flowers than high-nutrient plants. The results held in both populations, which differed greatly in the number and composition of floral scents produced. Conclusions The results reveal a strong genetic component both to scent composition and emission level, and partly contrasts with the only previous study that has assessed the susceptibility of floral volatile signals to variation in the abundance of nutrients. These results, and the tight coevolutionary relationship between Lithophragma plants and their specialized Greya moth pollinators, indicate that reproductive traits important to coevolving interactions, such as the floral scent of L. bolanderi, may be locally specialized and more canalized than other traits important for plant fitness.
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Affiliation(s)
- Magne Friberg
- Uppsala University, Department of Plant Ecology and Evolution, Evolutionary Biology Centre, EBC, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Mia T Waters
- University of California, Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, CA, USA
| | - John N Thompson
- University of California, Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, CA, USA
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42
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Delle-Vedove R, Schatz B, Dufay M. Understanding intraspecific variation of floral scent in light of evolutionary ecology. ANNALS OF BOTANY 2017; 120:1-20. [PMID: 28873948 PMCID: PMC5737645 DOI: 10.1093/aob/mcx055] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 03/29/2017] [Indexed: 05/29/2023]
Abstract
Background and Aims Among the various floral traits involved in pollinator attraction and potentially under selection mediated by pollinators, floral scent/fragrance has been less investigated than other components of floral phenotype. Whether or not pollinator-mediated selection impacts floral scents depends on the heritability of scent/fragrance and the occurrence of some variation within species. Although most studies have investigated how scent varies among species, growing amounts of data are available on variation at the intraspecific level. Methods The results of 81 studies investigating intraspecific variation of floral scents in 132 taxa were reviewed. For each study, whether variation was found in either identity, proportion or absolute quantities of volatile organic compounds (VOCs) was recorded, as well as information with the potential to explain variation, such as methodology, plant origin or pollination biology. Key Results Variation was found for almost all investigated species, both among individuals (among and sometimes within populations) and within individuals across different temporal scales. Cases in which such variation is a possible result of pollinator-mediated selection were analysed, by discussing separately selection related to variation in pollinator identity/behaviour among populations or across time, deceit pollination and sex-specific selection. Not surprisingly, in many cases, pollinator-mediated selection alone does not explain the observed variation in floral scent. This led us to review current knowledge on less investigated factors, such as selection mediated by natural enemies, genetic drift and gene flow, environmental constraints, phylogenetic inertia, or biochemical constraints that could be invoked to explain scent variation. Conclusions This review highlights the great potential of analysing floral scent variation and including it in integrated studies of floral phenotypes. We also have identified the current gaps in our understanding of this complex signal and we propose several methodological and conceptual future directions in this research area.
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Affiliation(s)
- Roxane Delle-Vedove
- Universite de Lille, CNRS UMR 8198 Evo-Eco-Paleo, 59655 Villeneuve d'Ascq Cedex, France
| | - Bertrand Schatz
- CEFE (Centre d’Ecologie Fonctionnelle et Evolutive), UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier, France
| | - Mathilde Dufay
- Universite de Lille, CNRS UMR 8198 Evo-Eco-Paleo, 59655 Villeneuve d'Ascq Cedex, France
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Borghi M, Fernie AR, Schiestl FP, Bouwmeester HJ. The Sexual Advantage of Looking, Smelling, and Tasting Good: The Metabolic Network that Produces Signals for Pollinators. TRENDS IN PLANT SCIENCE 2017; 22:338-350. [PMID: 28111171 DOI: 10.1016/j.tplants.2016.12.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/10/2016] [Accepted: 12/21/2016] [Indexed: 05/08/2023]
Abstract
A striking feature of the angiosperms that use animals as pollen carriers to sexually reproduce is the great diversity of their flowers with regard to morphology and traits such as color, odor, and nectar. These traits are underpinned by the synthesis of secondary metabolites such as pigments and volatiles, as well as carbohydrates and amino acids, which are used by plants to lure and reward animal pollinators. We review here the knowledge of the metabolic network that supports the biosynthesis of these compounds and the behavioral responses that these molecules elicit in the animal pollinators. Such knowledge provides us with a deeper insight into the ecology and evolution of plant-pollinator interactions, and should help us to better manage these ecologically essential interactions in agricultural ecosystems.
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Affiliation(s)
- Monica Borghi
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam-Golm, Germany
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008 Zürich
| | - Harro J Bouwmeester
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands; Present address: Plant Hormone Biology group, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
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Real-time divergent evolution in plants driven by pollinators. Nat Commun 2017; 8:14691. [PMID: 28291771 PMCID: PMC5424062 DOI: 10.1038/ncomms14691] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/23/2017] [Indexed: 12/28/2022] Open
Abstract
Pollinator-driven diversification is thought to be a major source of floral variation in plants. Our knowledge of this process is, however, limited to indirect assessments of evolutionary changes. Here, we employ experimental evolution with fast cycling Brassica rapa plants to demonstrate adaptive evolution driven by different pollinators. Our study shows pollinator-driven divergent selection as well as divergent evolution in plant traits. Plants pollinated by bumblebees evolved taller size and more fragrant flowers with increased ultraviolet reflection. Bumblebees preferred bumblebee-pollinated plants over hoverfly-pollinated plants at the end of the experiment, showing that plants had adapted to the bumblebees' preferences. Plants with hoverfly pollination became shorter, had reduced emission of some floral volatiles, but increased fitness through augmented autonomous self-pollination. Our study demonstrates that changes in pollinator communities can have rapid consequences on the evolution of plant traits and mating system.
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45
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Zu P, Schiestl FP. The effects of becoming taller: direct and pleiotropic effects of artificial selection on plant height in Brassica rapa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:1009-1019. [PMID: 27889935 DOI: 10.1111/tpj.13440] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/07/2016] [Accepted: 11/18/2016] [Indexed: 06/06/2023]
Abstract
Plant height is an important trait for plant reproductive success. Plant height is often under pollinator-mediated selection, and has been shown to be correlated with various other traits. However, few studies have examined the evolutionary trajectory of plant height under selection and the pleiotropic effects of plant height evolution. We conducted a bi-directional artificial selection experiment on plant height with fast cycling Brassica rapa plants to estimate its heritability and genetic correlations, and to reveal evolutionary responses to artificial selection on height and various correlated traits. With the divergent lines obtained through artificial selection, we subsequently conducted pollinator-choice assays and investigated resource limitation of fruit production. We found that plant height variation is strongly genetically controlled (with a realized heritability of 41-59%). Thus, plant height can evolve rapidly under phenotypic selection. In addition, we found remarkable pleiotropic effects in phenology, morphology, floral scent, color, nectar and leaf glucosinolates. Most traits were increased in tall-line plants, but flower size, UV reflection and glucosinolates were decreased, indicating potential trade-offs. Pollinators preferred plants of the tall selection lines over the short selection lines in both greenhouse experiments with bumblebees and field experiment with natural pollinators. We did not detect any differences in resource limitation between plants of the different selection lines. Overall, our study predicts that increased height should evolve under positive pollinator-mediated directional selection with potential trade-offs in floral signals and herbivore defense.
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Affiliation(s)
- Pengjuan Zu
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
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Jogesh T, Overson RP, Raguso RA, Skogen KA. Herbivory as an important selective force in the evolution of floral traits and pollinator shifts. AOB PLANTS 2016; 9:plw088. [PMID: 28011456 PMCID: PMC5499749 DOI: 10.1093/aobpla/plw088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/16/2016] [Accepted: 11/29/2016] [Indexed: 05/09/2023]
Abstract
Floral trait evolution is frequently attributed to pollinator-mediated selection but herbivores can play a key role in shaping plant reproductive biology. Here we examine the role of florivores in driving floral trait evolution and pollinator shifts in a recently radiated clade of flowering plants, Oenothera sect. Calylophus We compare florivory by a specialist, internal feeder, Mompha, on closely related hawkmoth- and bee-pollinated species and document variation in damage based on floral traits within sites, species and among species. Our results show that flowers with longer floral tubes and decreased floral flare have increased Mompha damage. Bee-pollinated flowers, which have substantially smaller floral tubes, experience on average 13% less Mompha florivory than do hawkmoth-pollinated flowers. The positive association between tube length and Mompha damage is evident even within sites of some species, suggesting that Mompha can drive trait differentiation at microevolutionary scales. Given that there are at least two independent shifts from hawkmoth to bee pollination in this clade, florivore-mediated selection on floral traits may have played an important role in facilitating morphological changes associated with transitions from hawkmoth to bee pollination.
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Affiliation(s)
- Tania Jogesh
- Chicago Botanic Garden, 1000 Lake Cook Road Glencoe, IL 60022 USA
| | - Rick P Overson
- Chicago Botanic Garden, 1000 Lake Cook Road Glencoe, IL 60022 USA
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Rd., Ithaca, NY 14853, USA
| | - Krissa A Skogen
- Chicago Botanic Garden, 1000 Lake Cook Road Glencoe, IL 60022 USA
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The effect of pollinators and herbivores on selection for floral signals: a case study in Brassica rapa. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9878-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Raguso RA. More lessons from linalool: insights gained from a ubiquitous floral volatile. CURRENT OPINION IN PLANT BIOLOGY 2016; 32:31-36. [PMID: 27286000 DOI: 10.1016/j.pbi.2016.05.007] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/23/2016] [Accepted: 05/25/2016] [Indexed: 05/25/2023]
Abstract
Linalool (3,7-dimethyl-1,6-octadien-3-ol) is a common floral volatile with two distinct enantiomers and related metabolites involved in the full spectrum of plant-pollinator interactions. Recent studies reveal a complex interplay between pollinator attraction and plant defense mediated by linalool and its derivatives, from the smallest (Arabidopsis, Mitella) to the largest (Datura) flowers studied. Accordingly, fig wasps, fungus gnats and moths of all sizes show remarkable electrophysiological, neural and behavioral sensitivity to different enantiomers and quantitative ratios of linalool in floral bouquets. The diverse functions of linalool, ranging from toxin to long distance pollinator attractant are discussed in the broader context of floral volatile ecology and evolution.
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Affiliation(s)
- Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Rd., Ithaca, NY 14853, USA.
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Henneresse T, Tyteca D. Insect Visitors and Potential Pollinators of Orchis militaris (Orchidaceae) in Southern Belgium. JOURNAL OF INSECT SCIENCE (ONLINE) 2016; 16:iew088. [PMID: 27694346 PMCID: PMC5043467 DOI: 10.1093/jisesa/iew088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/24/2016] [Indexed: 04/29/2023]
Abstract
As part of a research project on the food deception strategy in Orchis militaris (L.), the objective of this study was to identify insect visitors and potential pollinators of this orchid species in Belgium. In 2013, insects were collected over 2 d per site in five localities distributed in Southern Belgium (Wallonia). A total of 104 insects belonging to 49 species were caught. Dipterans were the most abundant visitors (50% of total specimens), followed by Hymenopterans (32%). Rhingia campestris Meigen, Bombylius venosus Mikan, Apis mellifera (L.), and Bombus lapidarius (L.) were the most abundant species. Only five specimens bore one to more than 10 pollinia: four honeybees (A. mellifera) and one bumblebee worker (B. lapidarius). These two species should be considered as potential pollinators in the study area, but probably not confirmed ones.
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Affiliation(s)
- Thomas Henneresse
- Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 4-5 box L7.07.04, B-1348, Louvain-la-Neuve
| | - Daniel Tyteca
- Biodiversity Research Centre, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 4-5 box L7.07.04, B-1348, Louvain-la-Neuve
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