1
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Cisternas-Fuentes A, Koski MH. Effective population size mediates the impact of pollination services on pollen limitation. Proc Biol Sci 2024; 291:20231519. [PMID: 38196350 PMCID: PMC10777167 DOI: 10.1098/rspb.2023.1519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/04/2023] [Indexed: 01/11/2024] Open
Abstract
Inadequate pollen receipt limits flowering plant reproduction worldwide. Ecological causes of pollen limitation (PL), like pollinator scarcity and low plant abundance, have been a primary research focus. The genetic diversity of plant populations could impact both quantity and quality components of PL in concert with ecological factors, yet empirical examples are lacking. We evaluated joint effects of ecological factors (flower abundance, pollinator visitation) and genetic effective population size (NE) on PL across 13 populations of the common herb Argentina anserina. We used a histological approach with 5504 styles from 1137 flowers to separate quantity and quality components of PL, and link these to reproductive output. NE and pollinator visitation interacted to shape PL, but NE had stronger direct effects. Effectively smaller populations experienced stronger quantity PL, and controlled crosses in a pollinator-free environment revealed that stigmatic pollen quantity was an intrinsic population-level attribute that increased with NE. Pollinator visitation enhanced pollen quality, but only in effectively larger populations. Quantity and quality PL negatively impacted fruit and seed set, respectively. Results highlight that PL is dictated by plant population genetic diversity in addition to commonly evaluated ecological factors. Efforts to support pollinators will more strongly enhance plant reproduction in genetically diverse populations.
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Affiliation(s)
- Anita Cisternas-Fuentes
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
- Departamento de botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Matthew H. Koski
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
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2
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Cisternas-Fuentes A, Koski MH. Drivers of strong isolation and small effective population size at a leading range edge of a widespread plant. Heredity (Edinb) 2023:10.1038/s41437-023-00610-z. [PMID: 37016137 DOI: 10.1038/s41437-023-00610-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 04/06/2023] Open
Abstract
Climate change has influenced species distributions worldwide with upward elevational shifts observed in many systems. Leading range edge populations, like those at upper elevation limits, are crucial for climate change responses but can exhibit low genetic diversity due to founder effects, isolation, or limited outbreeding. These factors can hamper local adaptation at range limits. Using the widespread herb, Argentina anserina, we measured ecological attributes (population density on the landscape, area of population occupancy, and plant and flower density) spanning a 1000 m elevation gradient, with high elevation populations at the range limit. We measured vegetative clonal potential in the greenhouse for populations spanning the gradient. We combined these data with a ddRAD-seq dataset to test the hypotheses that high elevation populations would exhibit ecological and genomic signatures of leading range edge populations. We found that population density on the landscape declined towards the high elevation limit, as is expected towards range edges. However, plant density was elevated within edge populations. In the greenhouse, high elevation plants exhibited stronger clonal potential than low elevation plants, likely explaining increased plant density in the field. Phylogeographic analysis supported more recent colonization of high elevation populations which were also more genetically isolated, had more extreme heterozygote excess and had smaller effective population size than low. Results support that colonization of high elevations was likely accompanied by increased asexuality, contributing to a decline in effective population size. Despite high plant density in leading edge populations, their small effective size, isolation and clonality could constrain adaptive potential.
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Affiliation(s)
- Anita Cisternas-Fuentes
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA.
| | - Matthew H Koski
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA.
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3
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Lüthi MN, Berardi AE, Mandel T, Freitas LB, Kuhlemeier C. Single gene mutation in a plant MYB transcription factor causes a major shift in pollinator preference. Curr Biol 2022; 32:5295-5308.e5. [PMID: 36473466 DOI: 10.1016/j.cub.2022.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/16/2022] [Accepted: 11/03/2022] [Indexed: 12/12/2022]
Abstract
Understanding the molecular basis of reproductive isolation and speciation is a key goal of evolutionary genetics. In the South American genus Petunia, the R2R3-MYB transcription factor MYB-FL regulates the biosynthesis of UV-absorbing flavonol pigments, a major determinant of pollinator preference. MYB-FL is highly expressed in the hawkmoth-pollinated P. axillaris, but independent losses of its activity in sister taxa P. secreta and P. exserta led to UV-reflective flowers and associated pollinator shifts in each lineage (bees and hummingbirds, respectively). We created a myb-fl CRISPR mutant in P. axillaris and studied the effect of this single gene on innate pollinator preference. The mutation strongly reduced the expression of the two key flavonol-related biosynthetic genes but only affected the expression of few other genes. The mutant flowers were UV reflective as expected but additionally contained low levels of visible anthocyanin pigments. Hawkmoths strongly preferred the wild-type P. axillaris over the myb-fl mutant, whereas both social and solitary bee preference depended on the level of visible color of the mutants. MYB-FL, with its specific expression pattern, small number of target genes, and key position at the nexus of flavonol and anthocyanin biosynthetic pathways, provides a striking example of evolution by single mutations of large phenotypic effect.
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Affiliation(s)
- Martina N Lüthi
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Andrea E Berardi
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Therese Mandel
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Loreta B Freitas
- Department of Genetics, Universidade Federal do Rio Grande do Sul, POB 15053, Porto Alegre, 91501970 Rio Grande do Sul, Brazil
| | - Cris Kuhlemeier
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
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4
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Eco-Evo-Devo of petal pigmentation patterning. Essays Biochem 2022; 66:753-768. [PMID: 36205404 DOI: 10.1042/ebc20220051] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 12/13/2022]
Abstract
Colourful spots, stripes and rings decorate the corolla of most flowering plants and fulfil important biotic and abiotic functions. Spatial differences in the pigmentation of epidermal cells can create these patterns. The last few years have yielded new data that have started to illuminate the mechanisms controlling the function, formation and evolution of petal patterns. These advances have broad impacts beyond the immediate field as pigmentation patterns are wonderful systems to explore multiscale biological problems: from understanding how cells make decisions at the microscale to examining the roots of biodiversity at the macroscale. These new results also reveal there is more to petal patterning than meets the eye, opening up a brand new area of investigation. In this mini-review, we summarise our current knowledge on the Eco-Evo-Devo of petal pigmentation patterns and discuss some of the most exciting yet unanswered questions that represent avenues for future research.
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5
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Cabon V, Kracht A, Seitz B, Kowarik I, von der Lippe M, Buchholz S. Urbanisation modulates the attractiveness of plant communities to pollinators by filtering for floral traits. OIKOS 2022. [DOI: 10.1111/oik.09071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Valentin Cabon
- Technische Univ. Berlin, Dept of Ecology Berlin Germany
- Univ. de Rennes 1, CNRS‐ECOBIO (Ecosystèmes, Biodiversité, Évolution) UMR 6553 Rennes France
| | - Alice Kracht
- Technische Univ. Berlin, Dept of Ecology Berlin Germany
| | - Birgit Seitz
- Technische Univ. Berlin, Dept of Ecology Berlin Germany
- Berlin‐Brandenburg Inst. of Advanced Biodiversity Research (BBIB) Berlin Germany
| | - Ingo Kowarik
- Technische Univ. Berlin, Dept of Ecology Berlin Germany
- Berlin‐Brandenburg Inst. of Advanced Biodiversity Research (BBIB) Berlin Germany
| | - Moritz von der Lippe
- Technische Univ. Berlin, Dept of Ecology Berlin Germany
- Berlin‐Brandenburg Inst. of Advanced Biodiversity Research (BBIB) Berlin Germany
| | - Sascha Buchholz
- Berlin‐Brandenburg Inst. of Advanced Biodiversity Research (BBIB) Berlin Germany
- Inst. of Landscape Ecology, Univ. of Münster Münster Germany
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6
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Koski MH, Finnell LM, Leonard E, Tharayil N. Elevational divergence in pigmentation plasticity is associated with selection and pigment biochemistry. Evolution 2022; 76:512-527. [PMID: 35038345 DOI: 10.1111/evo.14422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 11/19/2021] [Accepted: 11/30/2021] [Indexed: 11/29/2022]
Abstract
Phenotypic plasticity is predicted to evolve in environmentally variable habitats, or those experiencing a high frequency of strong selection. However, the evolution of plasticity may be constrained by costs or physiological constraints. In flowers, UV-absorbing pigmentation ameliorates UV damage to pollen, and is linked with elevated UV exposure. Whether plasticity contributes to this pattern remains unclear. Petals of Argentina anserina have larger UV-absorbing petal areas at high elevations where they experience higher and more variable UV exposure compared to low elevations. We measured UV-induced pigmentation plasticity in high- and low-elevation populations (hereafter, 'high, 'low'), and selection on pigmentation via male fitness. We dissected UV pigment biochemistry using metabolomics to explore biochemical mechanisms underlying plasticity. High displayed positive UV-induced pigmentation plasticity but low lacked plasticity. Selection favored elevated pigmentation under UV in high, supporting adaptive plasticity. In high, UV-absorption was conferred by flavonoids produced in one flavonoid pathway branch. However, in low, UV-absorption was associated with many compounds spanning many branches. Elevated plasticity was thus associated with reduced pigment diversity. The results are consistent with adaptive floral pigmentation plasticity in more extreme and variable environments. We discuss how biochemical underpinnings of pigmentation may permit or constrain the evolution of pigmentation plasticity. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Matthew H Koski
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634
| | - Lindsay M Finnell
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634
| | - Elizabeth Leonard
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634
| | - Nishanth Tharayil
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634
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7
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Finnell LM, Koski MH. A test of Sensory Drive in plant-pollinator interactions: heterogeneity in the signalling environment shapes pollinator preference for a floral visual signal. THE NEW PHYTOLOGIST 2021; 232:1436-1448. [PMID: 34287921 DOI: 10.1111/nph.17631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Sensory Drive predicts that habitat-dependent signal transmission and perception explain the diversification of communication signals. Whether Sensory Drive shapes floral evolution remains untested in nature. Pollinators of Argentina anserina prefer small ultraviolet (UV)-absorbing floral guides at low elevation but larger guides at high. However, mechanisms underlying differential preference are unclear. High elevation populations experience elevated UV irradiance and frequently flower against bare substrates rather than foliage, potentially impacting signal transmission and perception. At high and low elevation extremes, we experimentally tested the effects of UV light (ambient vs reduced) and floral backgrounds (foliage vs bare) on pollinator choice for UV guide size. We examined how different signalling environments shaped pollinator-perceived flower colour using visual system models. At high elevation, pollinators preferred locally common large UV guides under ambient UV, but lacked preference under reduced UV. Flies preferred large guides only against bare substrate, the common high elevation background. Ambient UV amplified contrast of large UV guides with floral backgrounds, and flowers contrasted more with bare ground than foliage. Results support that local signalling conditions contribute to pollinator preference for a floral visual signal, a key tenet of Sensory Drive. Components of Sensory Drive could shape floral signal evolution in other plants spanning heterogeneous signalling environments.
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Affiliation(s)
- Lindsay M Finnell
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Matthew H Koski
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA
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8
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Tunes P, Camargo MGG, Guimarães E. Floral UV Features of Plant Species From a Neotropical Savanna. FRONTIERS IN PLANT SCIENCE 2021; 12:618028. [PMID: 34025689 PMCID: PMC8137824 DOI: 10.3389/fpls.2021.618028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
Despite the wide interest in flower colours, only after the end of the nineteenth-century studies started to comprise floral UV reflection, which is invisible to humans but visible to the major groups of pollinators. Many flowers and inflorescences display colour patterns, an important signal for pollinators, promoted by the presence of at least two different colours within flowers or inflorescences, including colours in the UV waveband. For Neotropical savanna plant species, we characterised floral UV features using UV-photography and reflectance measurements. We tested (i) whether floral UV features were constrained by their shared ancestry, (ii) whether floral UV features were associated with pollinators, and (iii) whether floral UV features were associated with floral traits mediating these interactions, including floral resource, type of attraction unit and presence/absence of non-UV colour patterns. Of 80 plant species, ca. 70% were UV-patternless, most of them UV-absorbing. Approximately 30% presented one of three types of UV-patterns: bullseye, contrasting corolla markings oriented toward floral resources or contrasting reproductive structures, which were all considered as floral guides. Floral UV features were phylogenetically constrained and were associated with pollinators, floral resources and attraction unit, but not with non-UV colour patterns. UV-patternless flowers were associated with most of the pollination systems, while UV-patterned flowers were mainly associated with bee-pollination. UV-absorbing flowers comprised the only category with hawkmoth- and butterfly-pollinated flowers, and a high percentage of hummingbird-pollinated species. Nocturnal pollinated species were also commonly UV-absorbing, except for one UV-reflecting bat-pollinated species and one beetle-pollinated species with UV-reflecting stigmas. All types of floral UV features were associated with nectar; however, flowers with contrasting reproductive structures were mainly associated with pollen. There was an association between UV-absorbing species and the presence of inflorescences and intermediate attraction units. Our results evince that phylogenetic relatedness can constraint floral UV features' diversification, but combinations of evolutionary and ecological processes may be expected in this scenario.
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Affiliation(s)
- Priscila Tunes
- Laboratory of Ecology and Evolution of Plant-Animal Interactions, Postgraduate Program in Biological Sciences (Botany), Institute of Biosciences, São Paulo State University, Botucatu, Brazil
| | | | - Elza Guimarães
- Laboratory of Ecology and Evolution of Plant-Animal Interactions, Institute of Biosciences, São Paulo State University, Botucatu, Brazil
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9
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Martins AE, Arista M, Morellato LPC, Camargo MGG. Color signals of bee-pollinated flowers: the significance of natural leaf background. AMERICAN JOURNAL OF BOTANY 2021; 108:788-797. [PMID: 34056706 DOI: 10.1002/ajb2.1656] [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: 05/21/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Flower color is a primary pollinator attractant and generally adjusted to the cognitive system of the pollinators. The perception of flower color depends on the visual system of pollinators and also on environmental factors such as light conditions and the background against which flowers are displayed. METHODS Using bee-pollinated Fabaceae species as a model, we analyzed flower color diversity and compared flower color signals considering both the standard green and the natural leaf background of two tropical seasonally dry vegetations-a mountain rupestrian grassland (campo rupestre) and a woody savanna (cerrado)-compared to a nontropical Mediterranean shrubland. RESULTS By using natural background, bees discriminated color for 58% of the flowers in the campo rupestre and for only 43% in cerrado. Both vegetations were surpassed by 75% of bee color discrimination in Mediterranean vegetation. Chromatic contrast and purity were similar among the three vegetation types. Green contrast and brightness were similar between the tropical vegetations but differed from the Mediterranean shrubland. Green contrast differences were lost when using a standard green background, and most variables (purity, green contrast, and brightness) differed according to the background (natural or standard green) in all vegetations. CONCLUSIONS The natural background influenced bee perception of flower color regardless of vegetation. The background of the campo rupestre promoted green contrast for flowers, ensuring flower detection by pollinators and, along with bees, may also act as a selective pressure driving the diversity of flower colors in Fabaceae species. We highlight the importance of considering the natural background coloration when analyzing flower color signals.
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Affiliation(s)
- Amanda E Martins
- Department of Biodiversity, Phenology Lab, São Paulo State University (UNESP), Biosciences Institute, Av 24A, 1515, Rio Claro, São Paulo, 13506-900, Brazil
| | - Montserrat Arista
- Department of Plant Biology and Ecology, Universidad de Sevilla, Seville, 41080, Spain
| | - Leonor Patricia Cerdeira Morellato
- Department of Biodiversity, Phenology Lab, São Paulo State University (UNESP), Biosciences Institute, Av 24A, 1515, Rio Claro, São Paulo, 13506-900, Brazil
| | - Maria Gabriela G Camargo
- Department of Biodiversity, Phenology Lab, São Paulo State University (UNESP), Biosciences Institute, Av 24A, 1515, Rio Claro, São Paulo, 13506-900, Brazil
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10
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Sullivan CN, Koski MH. The effects of climate change on floral anthocyanin polymorphisms. Proc Biol Sci 2021; 288:20202693. [PMID: 33653138 DOI: 10.1098/rspb.2020.2693] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pigmentation affords resistance to abiotic stressors, and thus can respond adaptively or plastically to drought and extreme temperatures associated with global change. Plants frequently display variability in flower coloration that is underlain by anthocyanin pigmentation. While anthocyanin polymorphisms impact plant-animal interactions, they also impact reproductive performance under abiotic stress. We used descriptions of flower colour from over 1900 herbarium records representing 12 North American species spanning 124 years to test whether anthocyanin-based flower colour has responded to global change. Based on demonstrated abiotic associations with performance of anthocyanin colour morphs, we predicted pigmentation would increase in species experiencing increased aridity, but decline in those experiencing larger increases in temperature. We found that the frequency of reports of pigmented morphs increased temporally in some taxa but displayed subtle declines in others. Pigmentation was negatively associated with temperature and positively associated with vapour pressure deficit (a metric of aridity) across taxa. Species experiencing larger temperature increases over time displayed reductions in pigmentation, while those experiencing increases in aridity displayed increases in pigmentation. Change in anthocyanin-based floral colour was thus linked with climatic change. Altered flower coloration has the strong potential to impact plant-animal interactions and overall plant reproductive performance.
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Affiliation(s)
- Cierra N Sullivan
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Matthew H Koski
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
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11
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Dudek B, Schneider B, Hilger HH, Stavenga DG, Martínez-Harms J. Highly different flavonol content explains geographic variations in the UV reflecting properties of flowers of the corn poppy, Papaver rhoeas (Papaveraceae). PHYTOCHEMISTRY 2020; 178:112457. [PMID: 32692661 DOI: 10.1016/j.phytochem.2020.112457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/24/2020] [Accepted: 07/05/2020] [Indexed: 05/26/2023]
Abstract
Papaver rhoeas, the corn poppy, is a very common weed in cereal fields all over the world. Its flowers generally display a bright red coloration, but their reflectance in the ultraviolet (UV) wavelength range varies geographically. Whereas the UV reflectance of East Mediterranean flowers is minor, that of Central European ones is substantial. By comparing the pigmentation of the differently reflecting flowers, we found that only East Mediterranean flower petals contain high amounts of UV absorbing flavonol glycosides. The most abundant compounds were isolated by solid phase extraction and preparative HPLC, and their structures were elucidated by NMR and HRESI-MS, yielding seven kaempferol and quercetin glycosides, mostly unknown in P. rhoeas petals. Additionally, reflectance and transmittance measurements revealed that wavelength-selective scattering effects do not contribute to the flower color differences observed within this species. Possible abiotic and biotic factors influencing the UV reflecting properties of East Mediterranean and Central European poppies are discussed.
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Affiliation(s)
- Bettina Dudek
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745, Jena, Germany.
| | - Bernd Schneider
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745, Jena, Germany
| | - Hartmut H Hilger
- Department of Biology, Chemistry, Pharmacy, Institute of Biology - Botany, Freie Universität Berlin, Altensteinstr 6, D-14195, Berlin, Germany
| | - Doekele G Stavenga
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747, AG Groningen, the Netherlands
| | - Jaime Martínez-Harms
- INIA La Cruz, Instituto de Investigaciones Agropecuarias, Chorrillos 86, 2280454, La Cruz, Chile.
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12
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Koski MH, MacQueen D, Ashman TL. Floral Pigmentation Has Responded Rapidly to Global Change in Ozone and Temperature. Curr Biol 2020; 30:4425-4431.e3. [PMID: 32946752 DOI: 10.1016/j.cub.2020.08.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/03/2020] [Accepted: 08/24/2020] [Indexed: 12/22/2022]
Abstract
Across kingdoms, organisms ameliorate UV stress by increasing UV-absorbing pigmentation. Rapid ozone degradation during the 20th century resulted in elevated UV incidence, but pigmentation responses to this aspect of global change have yet to be demonstrated. In flowering plants, UV exposure favors larger areas of UV-absorbing pigmentation on petals, which protects pollen from UV-damage. Pigmentation also affects floral thermoregulation, suggesting climate warming may additionally impact pigmentation. We used 1,238 herbarium specimens collected from 1941 to 2017 to test whether change in UV floral pigmentation was associated with altered ozone and temperature in 42 species spanning three continents. We tested three predictions: first, UV-absorbing pigmentation will increase temporally and be correlated with reduced ozone (higher UV) when accounting for effects of temperature; second, taxa that experienced larger ozone declines will display larger increases in pigmentation; and third, taxa with anthers exposed to ambient UV will respond more strongly than those with anthers protected by petals. Globally, the extent of petal UV pigmentation increased significantly across taxa by ∼2% per year. However, temporal change was species specific-increasing in some taxa but declining in others. Species with exposed anthers experiencing larger declines in ozone displayed more dramatic pigmentation increases. For taxa with anthers enclosed within petals, pigmentation declined with increases in temperature, supporting a thermoregulatory role of UV pigmentation. Results document a rapid phenotypic response of floral pigmentation to anthropogenic climatic change, suggesting that global change may alter pollination through its impact on floral color, with repercussions for plant reproductive fitness.
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Affiliation(s)
- Matthew H Koski
- Clemson University, Department of Biological Sciences, Clemson, SC 29631, USA; University of Virginia, Department of Biology, Charlottesville, VA 22904, USA.
| | - Drew MacQueen
- University of Virginia Library Scholars Lab, PO Box 40010, Charlottesville, VA 22904-4129, USA
| | - Tia-Lynn Ashman
- University of Pittsburgh, Department of Biological Sciences, Pittsburgh, PA 15260, USA
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13
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Koski MH. The role of sensory drive in floral evolution. THE NEW PHYTOLOGIST 2020; 227:1012-1024. [PMID: 32112572 DOI: 10.1111/nph.16510] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/17/2020] [Indexed: 05/25/2023]
Abstract
Sensory drive theory posits that the evolution of communication signals is shaped by the sensory systems of receivers and the habitat conditions under which signals are received. It has inspired an enormous body of research, advancing our understanding of signal evolution and speciation in animals. In plants, the extreme diversification of floral signals has fascinated biologists for over a century. While processes involved in sensory drive probably play out in plant-pollinator communication, the theory has not been formally synthesized in this context. However, it has untapped potential to explain mechanisms underlying variation in pollinator preferences across populations, and how environmental conditions impact floral signal transmission and perception. Here I develop a framework of sensory drive for plant-pollinator interactions, identifying similarities and differences from its original conception. I then summarize studies that shed light on how the primary processes of sensory drive - habitat transmission, perceptual tuning, and signal matching - apply to the evolution of floral color and scent. Throughout, I propose research avenues and approaches to assess how sensory drive shapes floral diversity. This framework will be important for explaining patterns of extant floral diversity and examining how altered signaling conditions under global change will impact the evolutionary trajectory of floral traits.
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Affiliation(s)
- Matthew H Koski
- Department of Biological Sciences, Clemson University, Clemson, SC, 29631, USA
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14
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Martínez-Harms J, Hadar R, Márquez N, Menzel R, Shmida A, Stavenga DG, Vorobyev M. Enhanced UV-Reflection Facilitated a Shift in the Pollination System of the Red Poppy, Papaver rhoeas (Papaveraceae). PLANTS 2020; 9:plants9080927. [PMID: 32708009 PMCID: PMC7464000 DOI: 10.3390/plants9080927] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/06/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022]
Abstract
Evolutionary change is considered a major factor influencing the invasion of new habitats by plants. Yet, evidence on how such modifications promote range expansion remains rather limited. Here we investigated flower color modifications in the red poppy, Papaver rhoeas (Papaveraceae), as a result of its introduction into Central Europe and the impact of those modifications on its interactions with pollinators. We found that while flowers of Eastern Mediterranean poppies reflect exclusively in the red part of the spectrum, those of Central European poppies reflect both red and ultraviolet (UV) light. This change coincides with a shift from pollination by glaphyrid beetles (Glaphyridae) to bees. Glaphyrids have red-sensitive photoreceptors that are absent in bees, which therefore will not be attracted by colors of exclusively red-reflecting flowers. However, UV-reflecting flowers are easily detectable by bees, as revealed by visual modeling. In the North Mediterranean, flowers with low and high UV reflectance occur sympatrically. We hypothesize that Central European populations of P. rhoeas were initially polymorphic with respect to their flower color and that UV reflection drove a shift in the pollination system of P. rhoeas that facilitated its spread across Europe.
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Affiliation(s)
- Jaime Martínez-Harms
- Institut für Biologie-Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 1–3, 14195 Berlin, Germany; (R.H.); (N.M.); (R.M.)
- INIA La Cruz, Instituto de Investigaciones Agropecuarias, Chorrillos 86, La Cruz 2280454, Chile
- Correspondence:
| | - Ravit Hadar
- Institut für Biologie-Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 1–3, 14195 Berlin, Germany; (R.H.); (N.M.); (R.M.)
| | - Natalia Márquez
- Institut für Biologie-Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 1–3, 14195 Berlin, Germany; (R.H.); (N.M.); (R.M.)
| | - Randolf Menzel
- Institut für Biologie-Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 1–3, 14195 Berlin, Germany; (R.H.); (N.M.); (R.M.)
| | - Avi Shmida
- Department of Ecology, Evolution & Behaviour, Center for the Study of Rationality, The Hebrew University, Jerusalem 91904, Israel;
| | - Doekele G. Stavenga
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands;
| | - Misha Vorobyev
- School of Optometry and Vision Science, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand;
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Koski MH. Macroevolution of Flower Color Patterning: Biased Transition Rates and Correlated Evolution with Flower Size. FRONTIERS IN PLANT SCIENCE 2020; 11:945. [PMID: 32714351 PMCID: PMC7344184 DOI: 10.3389/fpls.2020.00945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Floral pigmentation patterns can both mediate plant-pollinator interactions and modify the abiotic environment of reproductive structures. To date, there have been no inquiries into the rate and directionality of macroevolutionary transitions between patterned and non-patterned petals despite their ecological importance and ubiquity across angiosperms. Petals in the Potentilleae tribe (Rosaceae) display color patterns in the ultraviolet (UV) and human-visible spectrum, or can be uniform in color (i.e., patternless). Using a phylogeny of Potentilleae, I test whether evolutionary transition rates between patterned and non-patterned petals are biased in either direction. I then examine whether UV and human-visible floral patterns are phylogenetically correlated and test the prediction that color patterns will evolve in concert with larger flowers if they function as guides to orient pollinators to floral rewards. I found that transition rates were biased toward petals that were uniform in color. Transition rates from patterned to uniformly colored petals were two and six times higher than the reverse for UV and human-visible pattern, respectively. The presence of UV and human-visible pattern evolved independently from one another. However, the evolution of human-visible pattern was associated with the evolution of larger flowers but the evolution of UV pattern was correlated with the evolution of smaller flowers. I posit that the transition bias toward non-patterned flowers may reflect developmental constraints on spatial regulation of pigments required to produce floral color patterning. The correlated evolution of larger flowers and human-visible pigmentation patterns support the hypothesis that nectar or pollen guides are more likely to evolve in larger-flowered species. This work provides insight into how transition rate bias and trait correlations can shape phylogenetic patterns of floral color pattern diversity.
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Borghi M, Perez de Souza L, Yoshida T, Fernie AR. Flowers and climate change: a metabolic perspective. THE NEW PHYTOLOGIST 2019; 224:1425-1441. [PMID: 31257600 DOI: 10.1111/nph.16031] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 06/24/2019] [Indexed: 05/18/2023]
Abstract
Adverse climatic conditions at the time of flowering severely hinder crop yields and threaten the interactions between plants and their pollinators. These features depend on a common trait: the metabolism of flowers. In this Viewpoint article, we aim to provide insight into the metabolic changes that occur in flowers in response to changes in climate and emphasize that these changes severely impact the fitness of autogamous and allogamous species, plant-pollinator interactions, and overall ecosystem health. We review the biochemical processes that lead to failure of gamete development and to alterations of color, scent and nectar secretion. Then, making use of open access expression data, we examine the expression of genes that may drive these changes in response to heat and drought. Finally, we present measurements of metabolites from flowers exposed to a heat wave and discuss how the results of this short-term experiment may give rise to misleading conclusions regarding the positive effect of heat on flower fitness. We hope this article draws attention to this often-neglected dynamic and its important consequences.
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Affiliation(s)
- Monica Borghi
- Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | | | - Takuya Yoshida
- Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
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17
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Klomberg Y, Dywou Kouede R, Bartoš M, Mertens JEJ, Tropek R, Fokam EB, Janeček Š. The role of ultraviolet reflectance and pattern in the pollination system of Hypoxis camerooniana (Hypoxidaceae). AOB PLANTS 2019; 11:plz057. [PMID: 31649811 PMCID: PMC6803167 DOI: 10.1093/aobpla/plz057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Apart from floral morphology and colours perceived by the human eye, ultraviolet (UV) reflectance acts as an important visual advertisement of numerous flowering plant species for pollinators. However, the effect of UV signalling on attracting pollinators of particular plant species is still insufficiently studied, especially in the Afrotropics. Therefore, we studied the pollination system of Hypoxis camerooniana in montane grasslands of Mount Cameroon, West/Central Africa. We focused mainly on the effects of the flowers' UV reflectance on its visitors. We experimentally removed UV reflection from petals either completely or partially. Thereafter, flower visitors were recorded and pistils were collected post-flowering to quantify germinated pollen tubes per treatments. The most important visitors were bees, followed by flies. Due to their contacts with reproductive organs bees are considered as the primary pollinators. Visitation rates were lower when UV reflectance was completely removed, whereas the decrease of frequency on half-treated flowers did not differ significantly from control treatments. The complete removal of UV also affected bees' landing behaviour, but not that of flies. We showed that the presence of UV reflectance is more important than UV pattern for bees visiting flowers of H. camerooniana. We hypothesize that exploiting all flowers irrespective of their pattern can be more efficient for pollinators in the open grasslands of high altitudes to spot these relatively scarce flowers by their UV reflectance. Furthermore, we highlight the necessity of both experimental and natural controls in similar studies to control for additional effects of the used UV manipulations. Many plants advertise their flowers with UV reflectance visible to their insect visitors. By manipulating the UV reflectance and pattern of Hypoxis camerooniana in the Afromontane grasslands of Mount Cameroon, we have shown how crucial it is for the predominant visitor, bees. Both bees' preferences for flowers and their behaviour during visits are influenced by changes in UV reflectance. However, the presence of some UV signal is more important than the specific pattern. Especially in montane grasslands with higher UV irradiation, the UV floral colours are important for recognition of flowers by potential pollinators.
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Affiliation(s)
- Yannick Klomberg
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czechia
| | - Raissa Dywou Kouede
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, PO Box 63 Buea, Cameroon
| | - Michael Bartoš
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, 37901 Třeboň, Czechia
| | - Jan E J Mertens
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czechia
| | - Robert Tropek
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czechia
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 37005 České Budějovice, Czechia
| | - Eric B Fokam
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, PO Box 63 Buea, Cameroon
| | - Štěpán Janeček
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czechia
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18
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Kemp JE, Bergh NG, Soares M, Ellis AG. Dominant pollinators drive non-random community assembly and shared flower colour patterns in daisy communities. ANNALS OF BOTANY 2019; 123:277-288. [PMID: 29992277 PMCID: PMC6344215 DOI: 10.1093/aob/mcy126] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/13/2018] [Indexed: 05/20/2023]
Abstract
Background and Aims As most plants rely on pollination for persistence in communities, pollination interactions should be important determinants of plant community assembly. Here, trait and phylogenetic null modelling approaches were combined with pollinator interaction networks to elucidate the processes structuring flower colour assembly patterns in Asteraceae communities in Namaqualand, South Africa. Methods Plant species were assigned to flower colour pattern categories (CPCs) that incorporate the complexity of the bulls-eye colour pattern, using pollinator vision models. Null models were used to assess whether daisy communities exhibit clustering (driven by filtering, facilitation or convergence) or overdispersion (driven by competitive exclusion or character displacement) of CPCs. Next, flower visitor networks were constructed for communities with non-random CPC assembly to confirm the functional role of pollinators in determining floral trait assembly. Key Results Plant species are unevenly distributed across CPCs, the majority of which are not phylogenetically conserved, suggesting that certain CPCs have a selective advantage. Clustering of CPCs in communities is more frequent than overdispersion, and this does not reflect non-random phylogenetic assembly. In most communities at least one CPC is overrepresented relative to null assemblages. Interaction networks show that each community has a single dominant pollinator that strongly interacts with the overrepresented CPC, suggesting a role for pollinator preferences in driving clustered assembly of CPCs within daisy communities. Conclusion This novel approach, which demonstrates non-random assembly of complex flower colour patterns and corroborates their functional association with particular pollinators, provides strong evidence that pollinators influence plant community assembly. Results suggest that in some community contexts the benefits of pollinator sharing outweigh the costs of heterospecific pollen transfer, generating clustered assembly. They also challenge the perception of generalized pollination in daisies, suggesting instead that complex daisy colour patterns represent a pollination syndrome trait linked to specific fly pollinators.
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Affiliation(s)
- Jurene E Kemp
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Nicola G Bergh
- The Compton Herbarium, Kirstenbosch Research Centre, South African National Biodiversity Institute, Newlands, Cape Town, South Africa
- The Bolus Herbarium, Department of Biological Sciences, H.W. Pearson Building, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Muri Soares
- The Bolus Herbarium, Department of Biological Sciences, H.W. Pearson Building, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Allan G Ellis
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
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Bergamo PJ, Telles FJ, Arnold SEJ, de Brito VLG. Flower colour within communities shifts from overdispersed to clustered along an alpine altitudinal gradient. Oecologia 2018; 188:223-235. [DOI: 10.1007/s00442-018-4204-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 06/06/2018] [Indexed: 12/14/2022]
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20
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Zhang G, Meng L, Wu Z, Zhang Z, Yin L, Yang Y, Duan Y. Natural selection on floral traits of Caltha scaposa (Ranunculaceae), an alpine perennial with generalized pollination system from Northwest Yunnan. PLANT DIVERSITY 2017; 39:202-207. [PMID: 30159512 PMCID: PMC6112295 DOI: 10.1016/j.pld.2017.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/16/2017] [Indexed: 05/23/2023]
Abstract
Floral traits, including those invisible to humans but visible to pollinators, that increase pollination efficiency may be selected by pollinators in plant species with pollen limitation of seed production, but the importance of pollinators as selective agents on different floral traits needs to be further quantified experimentally. In the present study, we examined selective strength on flower diameter, flower height, UV bulls-eye size, sepal size and UV proportion via female fitness in Caltha scaposa, based on open-pollinated and hand-pollinated flowers, through which pollinator-mediated selection was calculated for each of floral traits. Our results suggest that seed production of C. scaposa is pollen limited in natural conditions. There was directional selection (Δβpollinator = -0.12) for larger flowers in open-pollinated flowers, while no significant selection was found in flower height, UV bulls-eye size, sepal size or UV proportion. Statistically significant selection was found in UV bulls-eye size, sepal size and UV proportion in hand-pollinated flowers, but interactions with pollinators contributed only to flower diameter. We conclude that in C. scaposa, floral traits that are subjected to selection might be driven by multiple selective agents, and suggest the importance of investigating floral traits that are invisible to human but visible to pollinators in measuring pollinator-mediated selection via male fitness.
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Affiliation(s)
- Guopeng Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Lihua Meng
- School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China
| | - Zhikun Wu
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Zhiqiang Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Lingjuan Yin
- National Technical Secondary School of Lijiang, Lijiang 674119, PR China
| | - Yongping Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
| | - Yuanwen Duan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China
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21
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Moyers BT, Owens GL, Baute GJ, Rieseberg LH. The genetic architecture of UV floral patterning in sunflower. ANNALS OF BOTANY 2017; 120:39-50. [PMID: 28459939 PMCID: PMC5737206 DOI: 10.1093/aob/mcx038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 03/14/2017] [Indexed: 06/07/2023]
Abstract
Background and Aims The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus , a close relative of the domesticated sunflower. Methods A camera modified to capture UV light (320-380 nm) was used to phenotype floral UV patterning in an F 2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Key Results Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus . Conclusions The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently.
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Affiliation(s)
- Brook T. Moyers
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Room 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
| | - Gregory L. Owens
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Room 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
| | - Gregory J. Baute
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Room 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
| | - Loren H. Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Room 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
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22
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Harrison TL, Wood CW, Borges IL, Stinchcombe JR. No evidence for adaptation to local rhizobial mutualists in the legume Medicago lupulina. Ecol Evol 2017; 7:4367-4376. [PMID: 28649348 PMCID: PMC5478075 DOI: 10.1002/ece3.3012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/15/2017] [Accepted: 03/27/2017] [Indexed: 12/31/2022] Open
Abstract
Local adaptation is a common but not ubiquitous feature of species interactions, and understanding the circumstances under which it evolves illuminates the factors that influence adaptive population divergence. Antagonistic species interactions dominate the local adaptation literature relative to mutualistic ones, preventing an overall assessment of adaptation within interspecific interactions. Here, we tested whether the legume Medicago lupulina is adapted to the locally abundant species of mutualistic nitrogen-fixing rhizobial bacteria that vary in frequency across its eastern North American range. We reciprocally inoculated northern and southern M. lupulina genotypes with the northern (Ensifer medicae) or southern bacterium (E. meliloti) in a greenhouse experiment. Despite producing different numbers of root nodules (the structures in which the plants house the bacteria), neither northern nor southern plants produced more seeds, flowered earlier, or were more likely to flower when inoculated with their local rhizobia. We then used a pre-existing dataset to perform a genome scan for loci that showed elevated differentiation between field-collected plants that hosted different bacteria. None of the loci we identified belonged to the well-characterized suite of legume-rhizobia symbiosis genes, suggesting that the rhizobia do not drive genetic divergence between M. lupulina populations. Our results demonstrate that symbiont local adaptation has not evolved in this mutualism despite large-scale geographic variation in the identity of the interacting species.
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Affiliation(s)
- Tia L. Harrison
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Corlett W. Wood
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - Isabela L. Borges
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
| | - John R. Stinchcombe
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoONCanada
- Centre for Genome Evolution and FunctionUniversity of TorontoTorontoONCanada
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Koski MH, Ashman TL. Reproductive character displacement and environmental filtering shape floral variation between sympatric sister taxa. Evolution 2016; 70:2616-2622. [PMID: 27566693 DOI: 10.1111/evo.13042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 08/06/2016] [Accepted: 08/18/2016] [Indexed: 01/24/2023]
Abstract
Divergence in reproductive traits between closely related species that co-occur contributes to speciation by reducing interspecific gene flow. In flowering plants, greater floral divergence in sympatry than allopatry may reflect reproductive character displacement (RCD) by means of divergent pollinator-mediated selection or mating system evolution. However, environmental filtering (EF) would prevail for floral traits under stronger selection by abiotic factors than pollination, and lead to sympatric taxa being more phenotypically similar. We determine whether floral UV pigmentation and size show signatures of RCD or EF using a biogeographically informed sister taxa comparison. We determine whether 35 sister pairs in the Potentilleae tribe (Rosaceae) are allopatric or sympatric and confirm that sympatric sisters experience more similar bioclimatic conditions, an assumption of the EF hypothesis. We test whether interspecific differences are greater in allopatry or sympatry while accounting for divergence time. For UV pigmentation, sympatric sisters are more phenotypically similar than allopatric ones. For flower size, sympatric sisters show increased divergence with time since speciation but allopatric ones do not. We conclude that floral UV pigmentation shows a signature of EF, whereas flower size shows a signature of RCD. Discordant results between the traits suggest that the dominant selective agent differs between them.
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Affiliation(s)
- Matthew H Koski
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260. .,Current Address: Department of Biology, University of Virginia, Charlottesville, Virginia, 22904.
| | - Tia-Lynn Ashman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
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24
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Reginato M, Michelangeli FA. Diversity and constraints in the floral morphological evolution of Leandra s.str. (Melastomataceae). ANNALS OF BOTANY 2016; 118:445-58. [PMID: 27401539 PMCID: PMC4998978 DOI: 10.1093/aob/mcw116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/10/2016] [Accepted: 03/07/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Putative processes related to floral diversification and its relation to speciation are still largely unaccounted for in the Melastomataceae. Leandra s.str. is one of the most diverse lineages of the Neotropical Miconieae and ranks among the ten most diverse groups in the Atlantic Forest. Here, we describe the floral diversity of this lineage in a continuous framework and address several questions related to floral evolution and putative developmental and environmental constraints in its morphology. METHODS The morphological data set includes individual size measurements and shape scores (from elliptical Fourier analysis) for hypanthia, petals, stamens and styles. We evaluate whether there is evidence of correlation among these floral structures, shifts and convergent patterns, and association of these traits with elevation. KEY RESULTS Leandra s.str. flower structures present a strong phylogenetic signal and tend to be conserved among close relatives. The extremes in flower regimes seem to be quite distinct, but non-overlapping discrete flower types are not observed. Overall, the morphology of Leandra s.str. floral structures is correlated, and anther colour and inflorescence architecture correlate with flower structures. Additionally, the rates of species diversification and morphological evolution are correlated in most clades. CONCLUSIONS Although some flower regimes tend to occur in different elevational ranges, no significant association is observed. The general idea that hypanthium-ovary fusion is associated with fruit types in the Melastomataceae does not hold for Leandra s.str., where, instead, hypanthium-ovary fusion seems to be associated with anther shape. The lowest rate of flower morphological change, when compared with species diversification rates, is observed in the clade that possesses the most specialized flowers in the group. While stuck on a single general pollination system, Leandra s.str. seems to be greatly wandering around it, given the flower diversity and convergent patterns observed in this group.
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Affiliation(s)
- Marcelo Reginato
- Institute of Systematic Botany, The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY 10458, USA The Graduate Center, City University of New York, 365 5th Avenue, New York, NY 10016, USA
| | - Fabián A Michelangeli
- Institute of Systematic Botany, The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY 10458, USA
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25
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Berardi AE, Fields PD, Abbate JL, Taylor DR. Elevational divergence and clinal variation in floral color and leaf chemistry in Silene vulgaris. AMERICAN JOURNAL OF BOTANY 2016; 103:1508-23. [PMID: 27519429 DOI: 10.3732/ajb.1600106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 06/08/2016] [Indexed: 05/17/2023]
Abstract
PREMISE OF STUDY Environmental heterogeneity over a species range can lead to divergent selection among populations, leading to phenotypic differences. The plant flavonoid pathway controls key reproductive and defense-related traits and responds to selection and environmental stressors, allowing for hypotheses about phenotypic divergence across environmental gradients. We hypothesized that with increasing elevation, more flavonoids would be produced as a response to increased UV radiation and that plants would be better defended against herbivores. METHODS We measured floral color, flavonoids, and herbivory in natural populations of Silene vulgaris (Caryophyllaceae) along elevational transects in the French Alps. We correlated phenotypes with environmental variables and calculated genotypic divergence (FST) to compare with phenotypic divergence (PST). KEY RESULTS We found significant phenotypic variation in S. vulgaris along elevational gradients. Strong positive correlations were observed between floral color, leaf non-anthocyanidin flavonoid concentration, and elevation. Floral anthocyanin and leaf non-anthocyanidin flavonoid phenotypes negatively covaried with temperature and precipitation seasonality. Comparisons of PST to FST provided evidence for stabilizing selection on floral color among transects and divergent selection along the elevational gradient. CONCLUSIONS Flavonoid production increases along elevational gradients in S. vulgaris, with clinal variation in calyx anthocyanins and increasing leaf non-anthocyanin flavonoid concentrations. Despite the photoprotective and antiherbivore properties of some flavonoids, flavonoid production in flowers and leaves was correlated with population microclimatic variables: temperature and precipitation. Taken together, the results suggest that different flavonoid groups are targeted by selection in different tissues and provide evidence for divergent patterns of selection for flavonoids between high and low elevations.
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Affiliation(s)
- Andrea E Berardi
- Department of Biology, University of Virginia, P. O. Box 400328, Charlottesville, Virginia 22904-4328 USA
| | - Peter D Fields
- Department of Biology, University of Virginia, P. O. Box 400328, Charlottesville, Virginia 22904-4328 USA
| | - Jessica L Abbate
- Department of Biology, University of Virginia, P. O. Box 400328, Charlottesville, Virginia 22904-4328 USA
| | - Douglas R Taylor
- Department of Biology, University of Virginia, P. O. Box 400328, Charlottesville, Virginia 22904-4328 USA
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Koski MH, Ashman T. Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors. THE NEW PHYTOLOGIST 2016; 211:708-18. [PMID: 26987355 PMCID: PMC6681094 DOI: 10.1111/nph.13921] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/30/2016] [Indexed: 05/27/2023]
Abstract
Selection driven by biotic interactions can generate variation in floral traits. Abiotic selection, however, also contributes to floral diversity, especially with respect to patterns of pigmentation. Combining comparative studies of floral pigmentation and geography can reveal the bioclimatic factors that may drive macroevolutionary patterns of floral color. We create a molecular phylogeny and measure ultraviolet (UV) floral pattern for 177 species in the Potentilleae tribe (Rosaceae). Species are similar in flower shape and visible color but vary in UV floral pattern. We use comparative approaches to determine whether UV pigmentation variation is associated with geography and/or bioclimatic features (UV-B, precipitation, temperature). Floral UV pattern was present in half of the species, while others were uniformly UV-absorbing. Phylogenetic signal was detected for presence/absence of pattern, but among patterned species, quantitative variation in UV-absorbing area was evolutionarily labile. Uniformly UV-absorbing species tended to experience higher UV-B irradiance. Patterned species occurring at higher altitudes had larger UV-absorbing petal areas, corresponding with low temperature and high UV exposure. This analysis expands our understanding of the covariation of UV-B irradiance and UV floral pigmentation from within species to that among species, and supports the view that abiotic selection is associated with floral diversification among species.
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Affiliation(s)
- Matthew H. Koski
- Department of Biological SciencesUniversity of PittsburghPittsburghPA15260USA
- Present address:
Department of BiologyUniversity of VirginiaCharlottesvilleVA22904USA
| | - Tia‐Lynn Ashman
- Department of Biological SciencesUniversity of PittsburghPittsburghPA15260USA
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