1
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Lev-Yadun S. Visual-, Olfactory-, and Nectar-Taste-Based Flower Aposematism. PLANTS (BASEL, SWITZERLAND) 2024; 13:391. [PMID: 38337924 PMCID: PMC10857241 DOI: 10.3390/plants13030391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 02/12/2024]
Abstract
Florivory, i.e., flower herbivory, of various types is common and can strongly reduce plant fitness. Flowers suffer two very different types of herbivory: (1) the classic herbivory of consuming tissues and (2) nectar theft. Unlike the non-reversibility of consumed tissues, nectar theft, while potentially reducing a plant's fitness by lowering its attraction to pollinators, can, in various cases, be fixed quickly by the production of additional nectar. Therefore, various mechanisms to avoid or reduce florivory have evolved. Here, I focus on one of the flowers' defensive mechanisms, aposematism, i.e., warning signaling to avoid or at least reduce herbivory via the repelling of herbivores. While plant aposematism of various types was almost ignored until the year 2000, it is a common anti-herbivory defense mechanism in many plant taxa, operating visually, olfactorily, and, in the case of nectar, via a bitter taste. Flower aposematism has received only very little focused attention as such, and many of the relevant publications that actually demonstrated herbivore repellence and avoidance learning following flower signaling did not refer to repellence as aposematism. Here, I review what is known concerning visual-, olfactory-, and nectar-taste-based flower aposematism, including some relevant cases of mimicry, and suggest some lines for future research.
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Affiliation(s)
- Simcha Lev-Yadun
- Department of Biology & Environment, Faculty of Natural Sciences, University of Haifa-Oranim, Tivon 36006, Israel
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2
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Lev‐Yadun S. The phenomenon of red and yellow autumn leaves: Hypotheses, agreements and disagreements. J Evol Biol 2022; 35:1245-1282. [PMID: 35975328 PMCID: PMC9804425 DOI: 10.1111/jeb.14069] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 07/02/2022] [Accepted: 07/10/2022] [Indexed: 01/05/2023]
Abstract
Yellow and red autumn leaves are typical of many temperate/boreal woody plants. Since the 19th century, it has been either considered the non-functional outcome of chlorophyll degradation that unmasks the pre-existing yellow and red pigments or that the de novo synthesis of red anthocyanins in autumn leaves indicated that it should have a physiological function, although it was commonly ignored. Defending free amino acids and various other resources released especially following the breakdown of the photosynthetic system, and mobilizing them for storage in other organs before leaf fall, is the cornerstone of both the physiological and anti-herbivory hypotheses about the functions of yellow and red autumn leaf colouration. The complicated phenomenon of conspicuous autumn leaf colouration has received significant attention since the year 2000, especially because ecologists started paying attention to its anti-herbivory potential. The obvious imperfection of the hypotheses put forth in several papers stimulated many other scientists. Hot debates among physiologists, among ecologists, and between physiologists and ecologists have been common since the year 2000, first because the various functions of yellow and red autumn leaf colouration are non-exclusive, and second because many scientists were trained to focus on a single subject. Here, I will review the debates, especially between the photoprotective and the anti-herbivory hypotheses, and describe both the progress in their understanding and the required progress.
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Affiliation(s)
- Simcha Lev‐Yadun
- Department of Biology & Environment, Faculty of Natural SciencesUniversity of HaifaTivonIsrael
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3
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Huang L, Liu Y, Dou L, Pan S, Li Z, Zhang J, Li J. Mutualist- and antagonist-mediated selection contribute to trait diversification of flowers. PeerJ 2022; 10:e14107. [PMID: 36196403 PMCID: PMC9527018 DOI: 10.7717/peerj.14107] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 09/01/2022] [Indexed: 01/21/2023] Open
Abstract
Flowers are generally short-lived, and they all face a multidimensional challenge because they have to attract mutualists, compel them to vector pollen with minimal investment in rewards, and repel floral enemies during this short time window. Their displays are under complex selection, either consistent or conflicting, to maximize reproductive fitness under heterogeneous environments. The phenological or morphological mismatches between flowers and visitors will influence interspecific competition, resource access, mating success and, ultimately, population and community dynamics. To better understand the effects of the plant visitors on floral traits, it is necessary to determine the functional significance of specific floral traits for the visitors; how plants respond to both mutualists and antagonists through adaptive changes; and to evaluate the net fitness effects of biological mutualisms and antagonism on plants. In this review, we bring together insights from fields as diverse as floral biology, insect behavioral responses, and evolutionary biology to explain the processes and patterns of floral diversity evolution. Then, we discuss the ecological significance of plant responses to mutualists and antagonists from a community perspective, and propose a set of research questions that can guide the research field to integrate studies of plant defense and reproduction.
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Affiliation(s)
- Luyao Huang
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yang Liu
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Liwen Dou
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Shaobin Pan
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | | | - Jin Zhang
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Jia Li
- Shandong University of Traditional Chinese Medicine, Jinan, China
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4
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Alexandre NM, Haji D, Bakhtiari M, Chatla K, Aguilar JM, Arzumanova K, Whiteman NK. A Reference Genome Assembly of Hybrid-Derived California Wild Radish (Raphanus sativus × raphanistrum). J Hered 2022; 113:197-204. [PMID: 35575080 PMCID: PMC9113464 DOI: 10.1093/jhered/esab076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 01/30/2023] Open
Abstract
For agriculturally important plants, pollination and herbivory are 2 ecological factors that play into the success of crop yields. Each is also important in natural environments where invasive plants and their effect on species interactions may alter the native ecology. The California Wild Radish (Raphanus sativus × raphanistrum), a hybrid derived from an agriculturally important crop and a nonnative cultivar, is common in California. Remarkably, it has recently replaced wild populations of both progenitor species. Experiments on phenotypic variation for petal color and antiherbivore defenses suggest both pairs of polymorphisms are maintained as a result of pollinator- and herbivore-mediated natural selection. This species provides an opportunity to understand how natural selection shapes the evolution of ecologically important traits when traits are constrained by 2 opposing forces. Here we provide the genome assembly of the California Wild Radish displaying improvement to currently existing genomes for agronomically important crucifers. This genome sequence provides the tools to dissect the genomic architecture of traits related to herbivory and pollination using natural variation in the wild as well as the ability to infer demographic and selective history in the context of hybridization. Study systems like these will improve our understanding and predictions of evolutionary change for correlated traits.
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Affiliation(s)
- Nicolas M Alexandre
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Diler Haji
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Moe Bakhtiari
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Kamalakar Chatla
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Jessica M Aguilar
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Ksenia Arzumanova
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Noah K Whiteman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
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5
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Agati G, Guidi L, Landi M, Tattini M. Anthocyanins in photoprotection: knowing the actors in play to solve this complex ecophysiological issue. THE NEW PHYTOLOGIST 2021; 232:2228-2235. [PMID: 34449083 PMCID: PMC9291080 DOI: 10.1111/nph.17648] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 06/24/2021] [Indexed: 05/04/2023]
Affiliation(s)
- Giovanni Agati
- National Research Council of ItalyInstitute of Applied Physics ‘Nello Carrara’Via Madonna del Piano 10Sesto Fiorentino, FlorenceI‐50019Italy
| | - Lucia Guidi
- Department of Agriculture, Food and EnvironmentUniversity of PisaVia del Borghetto 80I‐56124PisaItaly
| | - Marco Landi
- Department of Agriculture, Food and EnvironmentUniversity of PisaVia del Borghetto 80I‐56124PisaItaly
| | - Massimiliano Tattini
- Institute for Sustainable Plant ProtectionNational Research Council of ItalyVia Madonna del Piano 10I‐50019Sesto Fiorentino, FlorenceItaly
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6
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Buide ML, Del Valle JC, Prado-Comesaña A, Narbona E. The effects of pollination, herbivory and autonomous selfing on the maintenance of flower colour variation in Silenelittorea. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:275-284. [PMID: 33179369 DOI: 10.1111/plb.13209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/30/2020] [Indexed: 05/23/2023]
Abstract
Intraspecific flower colour variation has been generally proposed to evolve as a result of selection driven by biotic or abiotic agents. In a polymorphic population of Silene littorea with pink- and white-flowered plants, we studied pollinators, analysed flower colour perception and tested for differences in pollinator visitation. We also experimentally analysed pollinator limitation in fruit and seed set, and the degree of autonomous selfing. The incidence of florivory and leaf herbivory was compared over 3-4 years. Silene littorea is mainly pollinated by bees and butterflies. Pollinators preferred pink flowers, which did not show pollinator limitation. On the contrary, white flowers showed pollinator limitation in fruit set. White-flowered plants had less floral display and higher levels of florivory than pink plants. Flower colour morphs of S. littorea can reproduce in the absence of pollinators by autonomous selfing, setting 20% and 12% of fruit and seeds in the pink morph and 27% and 20% in the white morph, respectively. Fruit set of white flowers produced by autonomous selfing did not differ from open-pollinated flowers. In conclusion, S. littorea is pollinated by insects of different orders that more frequently visit pink flowers, which is reflected in pollinator limitation of fruit set in white flowers. Moreover, this species has a mixed mating system in which both colour morphs can reproduce in the absence of pollinators by autonomous selfing, although white flowers mainly produce fruits by autogamy. We suggest that reproductive assurance by autonomous selfing helps to maintain flower colour polymorphism in this population.
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Affiliation(s)
- M L Buide
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
| | - J C Del Valle
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
| | - A Prado-Comesaña
- Department of Analytical and Food Chemistry, University of Vigo, Vigo, Spain
| | - E Narbona
- Department of Molecular Biology and Biochemical Engineering, Pablo de Olavide University, Seville, Spain
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7
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Dalrymple RL, Kemp DJ, Flores-Moreno H, Laffan SW, White TE, Hemmings FA, Moles AT. Macroecological patterns in flower colour are shaped by both biotic and abiotic factors. THE NEW PHYTOLOGIST 2020; 228:1972-1985. [PMID: 32533864 DOI: 10.1111/nph.16737] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/24/2020] [Indexed: 05/22/2023]
Abstract
There is a wealth of research on the way interactions with pollinators shape flower traits. However, we have much more to learn about influences of the abiotic environment on flower colour. We combine quantitative flower colour data for 339 species from a broad spatial range covering tropical, temperate, arid, montane and coastal environments from 9.25ºS to 43.75ºS with 11 environmental variables to test hypotheses about how macroecological patterns in flower colouration relate to biotic and abiotic conditions. Both biotic community and abiotic conditions are important in explaining variation of flower colour traits on a broad scale. The diversity of pollinating insects and the plant community have the highest predictive power for flower colouration, followed by mean annual precipitation and solar radiation. On average, flower colours are more chromatic where there are fewer pollinators, solar radiation is high, precipitation and net primary production are low, and growing seasons are short, providing support for the hypothesis that higher chromatic contrast of flower colours may be related to stressful conditions. To fully understand the ecology and evolution of flower colour, we should incorporate the broad selective context that plants experience into research, rather than focusing primarily on effects of plant-pollinator interactions.
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Affiliation(s)
- Rhiannon L Dalrymple
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Darrell J Kemp
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, Sydney, NSW, 2109, Australia
| | - Habacuc Flores-Moreno
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Shawn W Laffan
- School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Thomas E White
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2109, Australia
| | - Frank A Hemmings
- John T. Waterhouse Herbarium, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Angela T Moles
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
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8
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Dafni A, Tzohari H, Ben-Shlomo R, Vereecken NJ, Ne’eman G. Flower Colour Polymorphism, Pollination Modes, Breeding System and Gene Flow in Anemone coronaria. PLANTS (BASEL, SWITZERLAND) 2020; 9:E397. [PMID: 32210122 PMCID: PMC7154818 DOI: 10.3390/plants9030397] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/07/2020] [Accepted: 03/19/2020] [Indexed: 11/16/2022]
Abstract
The flower colour of Anemone coronaria (Ranunculaceae) is a genetically inherited trait. Such intra-specific flower colour polymorphism might be driven by pollinators, other non-pollinating agents, or by abiotic factors. We investigated the genetic relations among red, white and purple-blue flower colour morphs growing in 10 populations of A. coronaria in Israel, in relation to their breeding system, pollination modes, differential perception by bees and visitors' behaviour. Flowers of these three morphs differed in their reflectance that could be perceived by bees. Honeybees, solitary bees and flies demonstrated only partial preferences for the different colour morphs. No spontaneous self-pollination was found; however, fruit set under nets, excluding insects but allowing wind pollination, was not significantly lower than that of natural free pollinated flowers, indicating a potential role of wind pollination. Anemone coronaria flowers were visited by various insects, honeybees and Andrena sp. preferred the white and purple-blue morphs, while the syrphid flies preferred the white flowers. Thus, visitor behaviour can only partially explain the evolution or maintenance of the colour polymorphism. No significant genetic differences were found among the populations or colour morphs. Wind pollination, causing random gene flow, may explain why no significant genetic divergence was found among all studied populations and their colour morphs. The existence of monomorphic red populations, along other polymorphic populations, might be explained by linked resistance to aridity and/or grazing.
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Affiliation(s)
- Amots Dafni
- Department of Evolutionary Biology and Institute of Evolution, University of Haifa, Haifa 3498838, Israel;
| | - Hagai Tzohari
- Department of Evolutionary Biology and Institute of Evolution, University of Haifa, Haifa 3498838, Israel;
| | - Rachel Ben-Shlomo
- Department of Biology and Environment University of Haifa-Oranim, Tivon 36006, Israel;
| | - Nicolas J. Vereecken
- Agroecology & Pollination Group, Landscape Ecology & Plant Production Systems, Université Libre de Bruxelles (ULB), Boulevard du Triomphe CP 264/2, B-1050 Brussels, Belgium;
| | - Gidi Ne’eman
- Department of Biology and Environment University of Haifa-Oranim, Tivon 36006, Israel;
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9
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Rusman Q, Lucas-Barbosa D, Poelman EH, Dicke M. Ecology of Plastic Flowers. TRENDS IN PLANT SCIENCE 2019; 24:725-740. [PMID: 31204246 DOI: 10.1016/j.tplants.2019.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/16/2019] [Accepted: 04/25/2019] [Indexed: 05/20/2023]
Abstract
Plant phenotypic plasticity in response to herbivore attack includes changes in flower traits. Such herbivore-induced changes in flower traits have consequences for interactions with flower visitors. We synthesize here current knowledge on the specificity of herbivore-induced changes in flower traits, the underlying molecular mechanisms, and the ecological consequences for flower-associated communities. Herbivore-induced changes in flower traits seem to be largely herbivore species-specific. The extensive plasticity observed in flowers influences a highly connected web of interactions within the flower-associated community. We argue that the adaptive value of herbivore-induced plant responses and flower plasticity can be fully understood only from a community perspective rather than from pairwise interactions.
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Affiliation(s)
- Quint Rusman
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands.
| | - Dani Lucas-Barbosa
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Erik H Poelman
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
| | - Marcel Dicke
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA Wageningen, The Netherlands
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10
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Segar ST, Volf M, Sisol M, Pardikes NA, Souto-Vilarós D. Chemical cues and genetic divergence in insects on plants: conceptual cross pollination between mutualistic and antagonistic systems. CURRENT OPINION IN INSECT SCIENCE 2019; 32:83-90. [PMID: 31113637 DOI: 10.1016/j.cois.2018.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/20/2018] [Accepted: 11/25/2018] [Indexed: 06/09/2023]
Abstract
Cascading or reciprocal genetic diversification of herbivores, parasitoids, and pollinators can track chemotypic variation in host resources, and can lead to non-overlapping communities. Because plants simultaneously interact with both pollinators and herbivores, models investigating the genetic divergence of antagonistic herbivores and mutualistic pollinators should be merged in order to study how both processes interact using a common conceptual and methodological approach. We expect insects to mediate divergence in many systems, with outcomes depending on the level of pollinator or herbivore specialisation, and the relative selective pressures they impose. Applying approaches widely used to study insect pollinators, for example genomic tools and integration of behavioural, genetic and chemical data, to both pollinators and herbivores in the same system will facilitate our understanding of patterns of genetic divergence across multiple interacting species.
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Affiliation(s)
- Simon T Segar
- Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic; Department of Crop and Environment Sciences, Harper Adams University, UK.
| | - Martin Volf
- Molecular Interaction Ecology Group, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Mentap Sisol
- New Guinea Binatang Research Centre, Madang, Papua New Guinea
| | | | - Daniel Souto-Vilarós
- Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
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11
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Rusman Q, Lucas‐Barbosa D, Poelman EH. Dealing with mutualists and antagonists: Specificity of plant‐mediated interactions between herbivores and flower visitors, and consequences for plant fitness. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13035] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Quint Rusman
- Laboratory of EntomologyWageningen University Wageningen The Netherlands
| | - Dani Lucas‐Barbosa
- Laboratory of EntomologyWageningen University Wageningen The Netherlands
| | - Erik H. Poelman
- Laboratory of EntomologyWageningen University Wageningen The Netherlands
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12
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Narbona E, Wang H, Ortiz PL, Arista M, Imbert E. Flower colour polymorphism in the Mediterranean Basin: occurrence, maintenance and implications for speciation. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20 Suppl 1:8-20. [PMID: 28430395 DOI: 10.1111/plb.12575] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 04/18/2017] [Indexed: 05/20/2023]
Abstract
Flower colour polymorphism (FCP) is the occurrence of at least two discrete flower colour variants in the same population. Despite a vast body of research concerning the maintenance and evolutionary consequences of FCP, only recently has the spatial variation in morph frequencies among populations been explored. Here we summarise the biochemical and genetic basis of FCP, the factors that have been proposed to explain their maintenance, and the importance of FCP and its geographic variation in the speciation process. We also review the incidence of FCP in the environmentally heterogeneous Mediterranean Basin. Nearly 88% of Mediterranean FCP species showed anthocyanin-based polymorphisms. Concerning the evolutionary mechanisms that contribute to maintain FCP, selection by pollinators is suggested in some species, but in others, selection by non-pollinator agents, genetic drift or gene flow are also found; in some cases different processes interact in the maintenance of FCP. We emphasise the role of both autonomous selfing and clonal reproduction in FCP maintenance. Mediterranean polymorphic species show mainly monomorphic populations with only a few polymorphic ones, which generate clinal or mosaic patterns of variation in FCP. No cases of species with only polymorphic populations were found. We posit that different evolutionary processes maintaining polymorphism the Mediterranean Basin will result in a continuum of geographic patterns in morph compositions and relative frequencies of FCP species.
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Affiliation(s)
- E Narbona
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
| | - H Wang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- Institut des Sciences de l'Évolution de Montpellier (ISEM), Université de Montpellier, Montpellier, France
| | - P L Ortiz
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - M Arista
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - E Imbert
- Institut des Sciences de l'Évolution de Montpellier (ISEM), Université de Montpellier, Montpellier, France
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13
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Marquis RJ, Salazar D, Baer C, Reinhardt J, Priest G, Barnett K. Ode to Ehrlich and Raven or how herbivorous insects might drive plant speciation. Ecology 2017; 97:2939-2951. [PMID: 27870033 DOI: 10.1002/ecy.1534] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 06/27/2016] [Accepted: 07/07/2016] [Indexed: 11/06/2022]
Abstract
Fifty years ago, Ehrlich and Raven proposed that insect herbivores have driven much of plant speciation, particularly at tropical latitudes. There have been no explicit tests of their hypotheses. Indeed there were no proposed mechanisms either at the time or since by which herbivores might generate new plant species. Here we outline two main classes of mechanisms, prezygotic and postzygotic, with a number of scenarios in each by which herbivore-driven changes in host plant secondary chemistry might lead to new plant lineage production. The former apply mainly to a sympatric model of speciation while the latter apply to a parapatric or allopatric model. Our review suggests that the steps of each mechanism are known to occur individually in many different systems, but no scenario has been thoroughly investigated in any one system. Nevertheless, studies of Dalechampia and its herbivores and pollinators, and patterns of defense tradeoffs in trees on different soil types in the Peruvian Amazon provide evidence consistent with the original hypotheses of Ehrlich and Raven. For herbivores to drive sympatric speciation, our findings suggest that interactions with both their herbivores and their pollinators should be considered. In contrast, herbivores may drive speciation allopatrically without any influence by pollinators. Finally, there is evidence that these mechanisms are more likely to occur at low latitudes and thus more likely to produce new species in the tropics. The mechanisms we outline provide a predictive framework for further study of the general role that herbivores play in diversification of their host plants.
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Affiliation(s)
- Robert J Marquis
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Diego Salazar
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Department of Integrative Biology, University of California-Berkeley, 3040 Valley Life Sciences Bldg #3140, Berkeley, California, 94720, USA
| | - Christina Baer
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Jason Reinhardt
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Department of Forest Resources, University of Minnesota, 1530 Cleveland Ave. N., St. Paul, Minnesota, 55108, USA
| | - Galen Priest
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA
| | - Kirk Barnett
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Penrith, New South Wales, 2751, Australia
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14
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Strauss SY, Siemens DH, Decher MB, Mitchell-Olds T. ECOLOGICAL COSTS OF PLANT RESISTANCE TO HERBIVORES IN THE CURRENCY OF POLLINATION. Evolution 2017; 53:1105-1113. [PMID: 28565516 DOI: 10.1111/j.1558-5646.1999.tb04525.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/1998] [Accepted: 03/12/1999] [Indexed: 11/27/2022]
Abstract
In this paper, we examine how ecological costs of resistance might be manifested through plant relationships with pollinators. If defensive compounds are incorporated into floral structures or if they are sufficiently costly that fewer rewards are offered to pollinators, pollinators may discriminate against more defended plants. Here we consider whether directional selection for increased resistance to herbivores could be constrained by opposing selection through pollinator discrimination against more defended plants. We used artificial selection to create two populations of Brassica rapa plants that had high and low myrosinase concentrations and, consequently, high and low resistance to flea beetle herbivores. We measured changes in floral characters of plants in both damaged and undamaged states from these populations with different resistances to flea beetle attack. We also measured pollinator visitation to plants, including numbers of pollinators and measures of visit quality (numbers of flowers visited and time spent per flower). Damage from herbivores resulted in reduced petal size, as did selection for high resistance to herbivores later in the plant lifetime. In addition, floral display (number of open flowers) was also altered by an interaction between these two effects. Changes in floral traits translated into overall greater use of low-resistance, undamaged plants based on total amount of time pollinators spent foraging on plants. Total numbers of pollinators attracted to plants did not differ among treatments; however, pollinators spent significantly more time per flower on plants from the low-resistance population and tended to visit more flowers on these plants as well. Previous work by other investigators on the same pollinator taxa has shown that longer visit times are associated with greater male and female plant fitness. Because initial numbers of pollinators did not differ between selection regimes, palatability and/or amount of rewards offered by high- and low-resistance populations are likely to be responsible for these patterns. During periods of pollinator limitation, less defended plants may have a selective advantage and pollinator preferences may mediate directional selection imposed by herbivores. In addition, if pollinator preferences limit seed set in highly defended plants, then lower seed set previously attributed to allocation costs of defense may also reflect greater pollinator limitation in these plants relative to less defended plants.
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Affiliation(s)
- Sharon Y Strauss
- Center for Population Biology, University of California, Davis, California, 95616
| | - David H Siemens
- Max-Planck-Institute for Chemical Ecology, Tatzendpromenade 1A, 07745, Jena, Germany
| | - Meika B Decher
- Center for Population Biology, University of California, Davis, California, 95616
| | - Thomas Mitchell-Olds
- Max-Planck-Institute for Chemical Ecology, Tatzendpromenade 1A, 07745, Jena, Germany
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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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Sobral M, Losada M, Veiga T, Guitián J, Guitián J, Guitián P. Flower color preferences of insects and livestock: effects on Gentiana lutea reproductive success. PeerJ 2016; 4:e1685. [PMID: 27014509 PMCID: PMC4806593 DOI: 10.7717/peerj.1685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 01/22/2016] [Indexed: 11/28/2022] Open
Abstract
Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution. Gentiana lutea shows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed in G.lutea, play a role in G. lutea flower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding on G. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affect G. lutea reproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation of G. lutea is not affected by insect herbivores or grazing livestock.
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Affiliation(s)
- Mar Sobral
- Departamento de Bioloxía Celular e Ecoloxía/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - María Losada
- Departamento de Bioloxía Celular e Ecoloxía/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Tania Veiga
- Departamento de Bioloxía Celular e Ecoloxía/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Javier Guitián
- Departamento de Botánica/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - José Guitián
- Departamento de Bioloxía Celular e Ecoloxía/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Pablo Guitián
- Departamento de Botánica/Facultade de Bioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Johnson MT, Campbell SA, Barrett SC. Evolutionary Interactions Between Plant Reproduction and Defense Against Herbivores. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-112414-054215] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marc T.J. Johnson
- Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, L5L 1C6 Canada;
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2 Canada; ,
| | - Stuart A. Campbell
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2 Canada; ,
| | - Spencer C.H. Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2 Canada; ,
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Carlson JE, Holsinger KE. Extrapolating from local ecological processes to genus-wide patterns in colour polymorphism in South African Protea. Proc Biol Sci 2015; 282:20150583. [PMID: 25876847 PMCID: PMC4426637 DOI: 10.1098/rspb.2015.0583] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 03/20/2015] [Indexed: 11/12/2022] Open
Abstract
Polymorphic traits are central to many fundamental discoveries in evolution, yet why they are found in some species and not others remains poorly understood. We use the African genus Protea-within which more than 40% of species have co-occurring pink and white floral colour morphs-to ask whether convergent evolution and ecological similarity could explain the genus-wide pattern of polymorphism. First, we identified environmental correlates of pink morph frequency across 28 populations of four species. Second, we determined whether the same correlates could predict species-level polymorphism and monomorphism across 31 species. We found that pink morph frequency increased with elevation in Protea repens and three section Exsertae species, increased eastward in P. repens, and increased with seed predation intensity in section Exsertae. For cross-species comparisons, populations of monomorphic pink species occurred at higher elevations than populations of monomorphic white species, and 18 polymorphic species spanned broader elevational gradients than 13 monomorphic species. These results suggest that divergent selection along elevational clines has repeatedly favoured polymorphism, and that more uniform selection in altitudinally restricted species may promote colour monomorphism. Our findings are, to our knowledge, the first to link selection acting within species to the presence and absence of colour polymorphism at broader phylogenetic scales.
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Affiliation(s)
- Jane E Carlson
- Department of Ecology and Evolutionary Biology, University of Connecticut, U-3043, Storrs, CT 06269, USA
| | - Kent E Holsinger
- Department of Ecology and Evolutionary Biology, University of Connecticut, U-3043, Storrs, CT 06269, USA
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20
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McArt SH, Halitschke R, Salminen JP, Thaler JS. Leaf herbivory increases plant fitness via induced resistance to seed predators. Ecology 2013. [DOI: 10.1890/12-1664.1] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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21
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Variation among Four Populations of Erysimum Capitatum in Phenotype, Pollination and Herbivory over an Elevational Gradient. AMERICAN MIDLAND NATURALIST 2013. [DOI: 10.1674/0003-0031-169.2.259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Florivores prefer white versus pink petal color morphs in wild radish, Raphanus sativus. Oecologia 2012; 172:189-95. [DOI: 10.1007/s00442-012-2480-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
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Carlson JE, Holsinger KE. Direct and indirect selection on floral pigmentation by pollinators and seed predators in a color polymorphic South African shrub. Oecologia 2012; 171:905-19. [PMID: 23007806 DOI: 10.1007/s00442-012-2453-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 08/24/2012] [Indexed: 12/30/2022]
Abstract
The coexistence of different color morphs is often attributed to variable selection pressures across space, time, morph frequencies, or selection agents, but the routes by which each morph is favored are rarely identified. In this study we investigated factors that influence floral color polymorphisms on a local scale in Protea, within which approximately 40% of species are polymorphic. Previous work shows that seed predators and reproductive differences likely contribute to maintaining polymorphism in four Protea species. We explored whether selection acts directly or indirectly on floral color in two populations of Protea aurea, using path analysis of pollinator behavior, nectar production, seed predation, color, morphology, and maternal fecundity fitness components. We found that avian pollinators spent more time on white morphs, likely due to nectar differences, but that this had no apparent consequences for fecundity. Instead, the number of flowers per inflorescence underpinned many of the reproductively important differences between color morphs. White morphs had more flowers per inflorescence, which itself was positively correlated with nectar production, seed predator occurrence, and total long-term seed production. The number of seeds per plant to survive predation, in contrast, was not directly associated with color or any other floral trait. Thus, although color differences may be associated with conflicting selection pressures, the selection appears to be associated with the number of flowers per inflorescence and its unmeasured correlates, rather than with inflorescence color itself.
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Affiliation(s)
- Jane E Carlson
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA.
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24
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McCall AC, Barr CM. Why do florivores prefer hermaphrodites over females in Nemophila menziesii (Boraginaceae)? Oecologia 2012; 170:147-57. [DOI: 10.1007/s00442-012-2278-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
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25
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Gerchman Y, Dodek I, Petichov R, Yerushalmi Y, Lerner A, Keasar T. Beyond pollinator attraction: extra-floral displays deter herbivores in a Mediterranean annual plant. Evol Ecol 2011. [DOI: 10.1007/s10682-011-9509-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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26
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Dick CA, Buenrostro J, Butler T, Carlson ML, Kliebenstein DJ, Whittall JB. Arctic mustard flower color polymorphism controlled by petal-specific downregulation at the threshold of the anthocyanin biosynthetic pathway. PLoS One 2011; 6:e18230. [PMID: 21490971 PMCID: PMC3072389 DOI: 10.1371/journal.pone.0018230] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 02/23/2011] [Indexed: 12/28/2022] Open
Abstract
Intra- and interspecific variation in flower color is a hallmark of angiosperm diversity. The evolutionary forces underlying the variety of flower colors can be nearly as diverse as the colors themselves. In addition to pollinator preferences, non-pollinator agents of selection can have a major influence on the evolution of flower color polymorphisms, especially when the pigments in question are also expressed in vegetative tissues. In such cases, identifying the target(s) of selection starts with determining the biochemical and molecular basis for the flower color variation and examining any pleiotropic effects manifested in vegetative tissues. Herein, we describe a widespread purple-white flower color polymorphism in the mustard Parrya nudicaulis spanning Alaska. The frequency of white-flowered individuals increases with increasing growing-season temperature, consistent with the role of anthocyanin pigments in stress tolerance. White petals fail to produce the stress responsive flavonoid intermediates in the anthocyanin biosynthetic pathway (ABP), suggesting an early pathway blockage. Petal cDNA sequences did not reveal blockages in any of the eight enzyme-coding genes in white-flowered individuals, nor any color differentiating SNPs. A qRT-PCR analysis of white petals identified a 24-fold reduction in chalcone synthase (CHS) at the threshold of the ABP, but no change in CHS expression in leaves and sepals. This arctic species has avoided the deleterious effects associated with the loss of flavonoid intermediates in vegetative tissues by decoupling CHS expression in petals and leaves, yet the correlation of flower color and climate suggests that the loss of flavonoids in the petals alone may affect the tolerance of white-flowered individuals to colder environments.
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Affiliation(s)
- Cynthia A. Dick
- Department of Biology, Santa Clara University, Santa Clara, California, United States of America
| | - Jason Buenrostro
- Department of Biology, Santa Clara University, Santa Clara, California, United States of America
| | - Timothy Butler
- Department of Biology, Santa Clara University, Santa Clara, California, United States of America
| | - Matthew L. Carlson
- Biological Sciences Department, University of Alaska, Anchorage, Alaska, United States of America
| | - Daniel J. Kliebenstein
- Department of Plant Sciences, University of California Davis, Davis, California, United States of America
| | - Justen B. Whittall
- Department of Biology, Santa Clara University, Santa Clara, California, United States of America
- * E-mail:
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Halpern SL, Adler LS, Wink M. Leaf herbivory and drought stress affect floral attractive and defensive traits in Nicotiana quadrivalvis. Oecologia 2010; 163:961-71. [PMID: 20461411 DOI: 10.1007/s00442-010-1651-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 04/20/2010] [Indexed: 10/19/2022]
Abstract
Adaptive phenotypic plasticity allows sessile organisms such as plants to match trait expression to the particular environment they experience. Plasticity may be limited, however, by resources in the environment, by responses to prior environmental cues, or by previous interactions with other species, such as competition or herbivory. Thus, understanding the expression of plastic traits and their effects on plant performance requires evaluating trait expression in complex environments, rather than across levels of a single variable. In this study, we tested the independent and combined effects of two components of a plant's environment, herbivory and water availability, on the expression of attractive and defensive traits in Nicotiana quadrivalvis in the greenhouse. Damage and drought did not affect leaf nicotine concentrations but had additive and non-additive effects on floral attractive and defensive traits. Plants in the high water treatment produced larger flowers with more nectar than in the low water treatment. Leaf damage induced greater nectar volumes in the high water treatment only, suggesting that low water limited plastic responses to herbivore damage. Leaf damage also tended to induce higher nicotine concentrations in nectar, consistent with other studies showing that leaf damage can induce floral defenses. Our results suggest that there are separate and synergistic effects of leaf herbivory and drought on floral trait expression, and thus plasticity in response to complex environments may influence plant fitness via effects on floral visitation and defense.
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Affiliation(s)
- Stacey L Halpern
- Biology Department, Pacific University, 2043 College Way, Forest Grove, OR 97116, USA.
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28
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Carlson JE, Holsinger KE. Natural selection on inflorescence color polymorphisms in wild Protea populations: The role of pollinators, seed predators, and intertrait correlations. AMERICAN JOURNAL OF BOTANY 2010; 97:934-44. [PMID: 21622464 DOI: 10.3732/ajb.0900348] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PREMISE OF THE STUDY The processes maintaining flower color polymorphisms have long been of evolutionary interest. Mechanistic explanations include selection through pollinators, antagonists, local environments, drift, and pleiotropic effects. We examined the maintenance of inflorescence color polymorphisms in the genus Protea (Proteaceae) of South Africa, in which ∼40% of species contain different color morphs. • METHODS We studied 10 populations of four bird-pollinated Protea species and compared adult performance, floral and leaf morphology, vegetative pigmentation, germination, and seedling survival between co-occurring pink and white morphs. We also tested for differences in pollination success and pre-dispersal seed predation. • KEY RESULTS White morphs produced seeds 10% heavier and 3.5 times more likely to germinate, which all else being equal, should fuel positive selection on white. In one studied population per species, however, white morphs were more susceptible to seed predation by endophagous larvae. Pollinators had no morph-specific effects on female fecundity, as measured by amount or probability of seed set. Differences in stem color indicated that white morphs produced smaller quantities of pigment and associated compounds throughout, possibly explaining their higher seed palatability. • CONCLUSIONS Our findings suggest a mechanism for some white protea polymorphisms: deleterious pleiotropic effects on pink morphs are occasionally offset by reduced losses to seed-eating larvae. Because trends were repeated across species, we suggest that similar processes may also occur in other proteas, placing a new emphasis on seed predators for influencing some of South Africa's amazing floral diversity.
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Affiliation(s)
- Jane E Carlson
- Department of Ecology and Evolutionary Biology University of Connecticut, U-3043 Storrs, Connecticut 06269 USA
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Abstract
As the most visible role of anthocyanins is to impart colors, the adaptive significance of anthocyanins in plant reproductive organs is invariably attributed to the attraction of seed dispersers and pollinators. However, few studies suggested that anthocyanins in vegetative tissue might also function in plant defence, although the evidence for such a function is not particularly strong. Here, we investigated whether anthocyanins contribute to fruit defence against fruit-rot fungi. We found that the risk of fruit-rot in grape varieties infected with Botrytis cinerea decreased with increasing anthocyanin contents. Moreover, anthocyanin contents directly inhibited growth rates of nine fruit-rot fungi on agar plates. Anthocyanins reduced fungal growth by 50% in the concentrations that typically characterise unripe blackberries and by 95% in the concentrations that typify ripe blackberries. We conclude that anthocyanins in fruits not only function to attract animal vectors, but that they also contribute to fruit defence. The antifungal activity of anthocyanins might more widely explain their occurrence in various plant organs such as vegetative tissue and roots.
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Affiliation(s)
- H. Martin Schaefer
- Faculty of Biology, University of Freiburg, Department of Evolutionary Biology and Animal Ecology, Hauptstr. 1, 79104 Freiburg, Germany
| | - Michael Rentzsch
- Technische Universität Braunschweig, Institut für Lebensmittelchemie, Schleinitzstr. 20, 38106 Braunschweig, Germany
| | - Michael Breuer
- Department Ecology, State Institute for Viticulture and Enology, Merzhauser Str. 119, 79100 Freiburg, Germany
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Coberly LC, Rausher MD. PLEIOTROPIC EFFECTS OF AN ALLELE PRODUCING WHITE FLOWERS IN IPOMOEA PURPUREA. Evolution 2008; 62:1076-85. [DOI: 10.1111/j.1558-5646.2008.00355.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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31
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Autumn leaf colouration: a new hypothesis involving plant–ant mutualism via aphids. Naturwissenschaften 2008; 95:671-6. [DOI: 10.1007/s00114-008-0366-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 01/14/2008] [Accepted: 02/15/2008] [Indexed: 11/30/2022]
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32
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Rausher M. Evolutionary Transitions in Floral Color. INTERNATIONAL JOURNAL OF PLANT SCIENCES 2008; 169:7-21. [PMID: 0 DOI: 10.1086/523358] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Cazetta E, Schaefer HM, Galetti M. Does attraction to frugivores or defense against pathogens shape fruit pulp composition? Oecologia 2007; 155:277-86. [DOI: 10.1007/s00442-007-0917-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 11/04/2007] [Indexed: 11/30/2022]
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Pohl N, Carvallo G, Botto-Mahan C, Medel R. Nonadditive effects of flower damage and hummingbird pollination on the fecundity of Mimulus luteus. Oecologia 2006; 149:648-55. [PMID: 16896778 DOI: 10.1007/s00442-006-0479-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
Flower herbivory and pollination have been described as interactive processes that influence each other in their effects on plant reproductive success. Few studies, however, have so far examined their joint effects in natural populations. In this paper we evaluate the influence of flower damage and pollination by the hummingbird Oreotrochilus leucopleurus on the fecundity of the Andean monkey flower Mimulus luteus. We performed a 2x2 factorial experiment, with artificial clipping of lower petals and selective exclusion of the hummingbird as main factors. In spite of the relatively low proportion (27.5%) of the variance in seed production accounted for by the full factorial model, artificial damage and hummingbird exclusion, as well as their interaction, were highly significant, indicating nonadditive effects of factors on plant fecundity. In the presence of hummingbirds, undamaged flowers had a seed production that was 1.7-fold higher than for damaged flowers, suggesting that the effect of flower damage on female reproductive success occurs probably as a consequence of hummingbird discrimination against damaged corollas. This result indicates that the impact of flower herbivory on plant fecundity was contingent on the presence or absence of hummingbirds, suggesting that pollinators may indirectly select for undamaged and probably resistant flower phenotypes. A second interaction effect revealed that undamaged flowers produced 78.5% more seeds in the absence of rather than in the presence of O. leucopleurus, raising the question of the ecological mechanism involved. We suggest that the strong territorial behavior exhibited by the bee Centris nigerrima may confine the foraging activities of the remaining bee species to safe sites within exclosures. Overall, our results provide evidence that hummingbird pollination and flower herbivory have interdependent effects on M. luteus fecundity, which indicates that it will be difficult to predict their ecological and evolutionary consequences unless interactions are analyzed in an integrated form.
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Affiliation(s)
- Nélida Pohl
- Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697-2525, USA
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M. Eckhart V, S. Rushing N, M. Hart G, D. Hansen J. Frequency-dependent pollinator foraging in polymorphicClarkia xantianassp.xantianapopulations: implications for flower colour evolution and pollinator interactions. OIKOS 2006. [DOI: 10.1111/j.0030-1299.2006.14289.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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McCall AC, Karban R. Induced defense in Nicotiana attenuata (Solanaceae) fruit and flowers. Oecologia 2005; 146:566-71. [PMID: 16328552 DOI: 10.1007/s00442-005-0284-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 10/12/2005] [Indexed: 10/25/2022]
Abstract
Plants protect themselves against herbivory using a continuum of strategies, ranging from constitutive defenses to intermittent induced responses. Induced defenses may not provide immediate and maximum protection, but could be advantageous when continuous defense is either energetically or ecologically costly. As such, induced defenses in flowers could help defend relatively valuable tissue while keeping reproductive structures accessible and attractive to pollinators. Thus far, no one has demonstrated the efficacy of induced defenses against floral herbivores (florivores) in the field. Here we show that mechanical leaf damage in wild tobacco, Nicotiana attenuata (Solanaceae), reduced both flower and fruit herbivory in the field and that exogenous application of methyl jasmonate, a potent elicitor of induced responses, reduced both leaf and floral damage in natural populations. This result is consistent with a survey of damage in the field, which showed a negative relationship between leaf damage and flower and fruit damage. Although optimal defense theory predicts that induced defenses should be rare in reproductive tissues, owing to their high fitness value, our results suggest otherwise. Induced defenses in leaves and reproductive tissues may allow plants to respond effectively to the concomitant pressures of defending against herbivory and attracting pollinators.
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Affiliation(s)
- Andrew C McCall
- Center for Population Biology, Department of Entomology, University of California, Davis, CA, 95616, USA.
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Irwin RE, Strauss SY. Flower color microevolution in wild radish: evolutionary response to pollinator-mediated selection. Am Nat 2004; 165:225-37. [PMID: 15729652 DOI: 10.1086/426714] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Accepted: 10/04/2004] [Indexed: 11/04/2022]
Abstract
Evolutionary ecologists are fundamentally interested in how species interactions affect evolutionary change. We tested the degree to which plant-pollinator interactions affect the frequency of flower color morphs of Raphanus sativus. Petal color in R. sativus is determined by two independently assorting loci, producing four petal colors (yellow, white, pink, and bronze). We assessed the impact of pollinator discrimination on changes in flower color variation by comparing the frequency of colors produced in the presence (open pollination) versus absence (null pollination) of pollinator discrimination. We also assessed the impact of postpollination and developmental effects on progeny colors using equal pollinations with all four color morphs. Our results from open pollinations found an overrepresentation of yellow progeny in the next generation, when compared with both null pollinations and cumulative ratios based on Hardy-Weinberg and linkage equilibria assumptions. When these results were combined with those from equal pollinations, the overrepresentation of yellow could be attributed to selection from pollinators. Yet, surveys in the field the following year found no flower color frequency changes in the next generation. These results illustrate that flower color microevolution can be driven by both pollinator discrimination and other nonpollinator selective forces acting during the seed-to-adult transition, countering selection imposed by pollinators.
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Affiliation(s)
- Rebecca E Irwin
- Center for Population Biology, University of California, Davis, California 95616, USA.
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Frey FM. OPPOSING NATURAL SELECTION FROM HERBIVORES AND PATHOGENS MAY MAINTAIN FLORAL-COLOR VARIATION IN CLAYTONIA VIRGINICA (PORTULACACEAE). Evolution 2004. [DOI: 10.1554/03-477] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gómez JM. Herbivory reduces the strength of pollinator-mediated selection in the Mediterranean herb Erysimum mediohispanicum: consequences for plant specialization. Am Nat 2003; 162:242-56. [PMID: 12858267 DOI: 10.1086/376574] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2002] [Accepted: 02/18/2003] [Indexed: 11/03/2022]
Abstract
In this study, I tested whether selection occurring on several morphological and floral traits in Erysimum mediohispanicum (Cruciferae) is modified by the effects of herbivores. Six plots were established in 1997 in the Sierra Nevada, Spain; three were fenced to exclude native ungulates, and the remaining were open to ungulates. I determined pollinator and ungulate preferences for plant traits and their effect on plant fecundity. Then I compared the selection regimes between plants excluded from herbivores and plants open to them. When ungulates were absent, I found significant selection on flower number, reproductive stalk height, basal diameter of the stalks, petal length, and inner diameter of the flowers. When ungulates were present, selection on floral traits completely disappeared, and selection strength on flower number and morphological traits decreased. This effect was due to the ungulate preference for larger plants and the phenotypic correlations between plant size and floral traits. Results suggest that pollinator-mediated selection can be disrupted by conflicting effects of plant enemies acting during or subsequent to pollination. An accurate picture of the pollinator role as selective pressure requires the consideration of the entire life cycle of the plant as well as the ecological scenario in which the interactions occur.
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Affiliation(s)
- Jose M Gómez
- Departamento de Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.
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Irwin RE, Strauss SY, Storz S, Emerson A, Guibert G. THE ROLE OF HERBIVORES IN THE MAINTENANCE OF A FLOWER COLOR POLYMORPHISM IN WILD RADISH. Ecology 2003. [DOI: 10.1890/0012-9658(2003)084[1733:trohit]2.0.co;2] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Armbruster WS. Can indirect selection and genetic context contribute to trait diversification? A transition-probability study of blossom-colour evolution in two genera. J Evol Biol 2002. [DOI: 10.1046/j.1420-9101.2002.00399.x] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Gómez JM, Zamora R. Spatial Variation in the Selective Scenarios of Hormathophylla spinosa (Cruciferae). Am Nat 2000; 155:657-668. [PMID: 10777438 DOI: 10.1086/303353] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effects of multispecific systems containing both mutualistic and antagonistic interacting organisms on the evolution of plant traits have seldom been analyzed. We studied the selection exerted by several species of herbivores and pollinators in three populations of Hormathophylla spinosa (Cruciferae) in the Sierra Nevada (Spain) over 4 yr by using path analyses and structural equation modeling (SEM). The main selective pressures in our study sites were ungulates and pollinators. However, the importance of each kind of interacting organism differed among populations. Our results indicate a selection mosaic among populations of H. spinosa in the Sierra Nevada caused by the spatial variation in the relative importance of different interactions as selective pressures. We found two main selective scenarios, depending on the presence or absence of ungulates. In the populations with low ungulate pressure, there was positive phenotypic selection in flower number per plant and in flower density (mediated by nectarivorous pollinators). In the two populations with high ungulate pressure, there was a strong positive, ungulate-mediated selection in thorn density. Our results suggest that the application of SEM to several populations simultaneously monitored might help to isolate the major selection pressures on local populations and identify potential differences in selection among populations, becoming a useful exploratory approach to study the geographical variation of selection in complex systems.
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