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Agarwal R, Althoff DM. Extreme specificity in obligate mutualism-A role for competition? Ecol Evol 2024; 14:e11628. [PMID: 38911491 PMCID: PMC11190587 DOI: 10.1002/ece3.11628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 05/31/2024] [Accepted: 06/10/2024] [Indexed: 06/25/2024] Open
Abstract
Obligate mutualisms, reciprocally obligate beneficial interactions, are some of the most important mutualisms on the planet, providing the basis for the evolution of the eukaryotic cell, the formation and persistence of terrestrial ecosystems and the establishment and expansion of coral reefs. In addition, these mutualisms can also lead to the diversification of interacting partner species. Accompanying this diversification is a general pattern of a high degree of specificity among interacting partner species. A survey of obligate mutualisms demonstrates that greater than half of these systems have only one or two mutualist species on each side of the interaction. This is in stark contrast to facultative mutualisms that can have dozens of interacting mutualist species. We posit that the high degree of specificity in obligate mutualisms is driven by competition within obligate mutualist guilds that limits species richness. Competition may be particularly potent in these mutualisms because mutualistic partners are totally dependent on each other's fitness gains, which may fuel interspecific competition. Theory and the limited number of empirical studies testing for the role of competition in determining specificity suggest that competition may be an important force that fuels the high degree of specificity. Further empirical research is needed to dissect the relative roles of trait complementarity, mutualism regulation, and competition among mutualist guild members in determining mutualism specificity at local scales.
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Affiliation(s)
- Renuka Agarwal
- Department of BiologySyracuse UniversitySyracuseNew YorkUSA
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Song B, Chen J, Lev-Yadun S, Niu Y, Gao Y, Ma R, Armbruster WS, Sun H. Multifunctionality of angiosperm floral bracts: a review. Biol Rev Camb Philos Soc 2024; 99:1100-1120. [PMID: 38291834 DOI: 10.1111/brv.13060] [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: 11/28/2022] [Revised: 01/02/2024] [Accepted: 01/22/2024] [Indexed: 02/01/2024]
Abstract
Floral bracts (bracteoles, cataphylls) are leaf-like organs that subtend flowers or inflorescences but are of non-floral origin; they occur in a wide diversity of species, representing multiple independent origins, and exhibit great variation in form and function. Although much attention has been paid to bracts over the past 150 years, our understanding of their adaptive significance remains remarkably incomplete. This is because most studies of bract function and evolution focus on only one or a few selective factors. It is widely recognised that bracts experience selection mediated by pollinators, particularly for enhancing pollinator attraction through strong visual, olfactory, or echo-acoustic contrast with the background and through signalling the presence of pollinator rewards, either honestly (providing rewards for pollinators), or deceptively (attraction without reward or even trapping pollinators). However, studies in recent decades have demonstrated that bract evolution is also affected by agents other than pollinators. Bracts can protect flowers, fruits, or seeds from herbivores by displaying warning signals, camouflaging conspicuous reproductive organs, or by providing physical barriers or toxic chemicals. Reviews of published studies show that bracts can also promote seed dispersal and ameliorate the effects of abiotic stressors, such as low temperature, strong ultraviolet radiation, heavy rain, drought, and/or mechanical abrasion, on reproductive organs or for the plants' pollinators. In addition, green bracts and greening of colourful bracts after pollination promote photosynthetic activity, providing substantial carbon (photosynthates) for fruit or seed development, especially late in a plant's life cycle or season, when leaves have started to senesce. A further layer of complexity derives from the fact that the agents of selection driving the evolution of bracts vary between species and even between different developmental stages within a species, and selection by one agent can be reinforced or opposed by other agents. In summary, our survey of the literature reveals that bracts are multifunctional and subject to multiple agents of selection. To understand fully the functional and evolutionary significance of bracts, it is necessary to consider multiple selection agents throughout the life of the plant, using integrative approaches to data collection and analysis.
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Affiliation(s)
- Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - Jiaqi Chen
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
- School of Life Sciences, Yunnan University, Huannan Road, East of University Town, Chenggong New Area, Kunming, 650500, China
| | - Simcha Lev-Yadun
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa at Oranim, Kiryat Tiv'on, 36006, Israel
| | - Yang Niu
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - Yongqian Gao
- Yunnan Forestry Technological College, 1 Jindian, Kunming, 650224, China
| | - Rong Ma
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, PO Box 757000, Fairbanks, AK, 99775, USA
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, China
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Dötterl S, Gershenzon J. Chemistry, biosynthesis and biology of floral volatiles: roles in pollination and other functions. Nat Prod Rep 2023; 40:1901-1937. [PMID: 37661854 DOI: 10.1039/d3np00024a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Covering: 2010 to 2023Floral volatiles are a chemically diverse group of plant metabolites that serve multiple functions. Their composition is shaped by environmental, ecological and evolutionary factors. This review will summarize recent advances in floral scent research from chemical, molecular and ecological perspectives. It will focus on the major chemical classes of floral volatiles, on notable new structures, and on recent discoveries regarding the biosynthesis and the regulation of volatile emission. Special attention will be devoted to the various functions of floral volatiles, not only as attractants for different types of pollinators, but also as defenses of flowers against enemies. We will also summarize recent findings on how floral volatiles are affected by abiotic stressors, such as increased temperatures and drought, and by other organisms, such as herbivores and flower-dwelling microbes. Finally, this review will indicate current research gaps, such as the very limited knowledge of the isomeric pattern of chiral compounds and its importance in interspecific interactions.
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Affiliation(s)
- Stefan Dötterl
- Department of Environment & Biodiversity, Paris Lodron University Salzburg, Hellbrunnerstr 34, 5020 Salzburg, Austria.
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany.
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Li Y, Niu Z, Zhu M, Wang Z, Xu R, Li M, Zheng Z, Lu Z, Dong C, Hu H, Yang Y, Wu Y, Wang D, Yang J, Zhang J, Wan D, Abbott R, Liu J, Yang Y. Multi-omics data provide insight into the adaptation of the glasshouse plant Rheum nobile to the alpine subnival zone. Commun Biol 2023; 6:906. [PMID: 37667004 PMCID: PMC10477342 DOI: 10.1038/s42003-023-05271-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 08/22/2023] [Indexed: 09/06/2023] Open
Abstract
Subnival glasshouse plants provide a text-book example of high-altitude adaptation with reproductive organs enclosed in specialized semi-translucent bracts, monocarpic reproduction and continuous survival under stress. Here, we present genomic, transcriptomic and metabolomic analyses for one such plant, the Noble rhubarb (Rheum nobile). Comparative genomic analyses show that an expanded number of genes and retained genes from two recent whole-genome duplication events are both relevant to subnival adaptation of this species. Most photosynthesis genes are downregulated within bracts compared to within leaves, and indeed bracts exhibit a sharp reduction in photosynthetic pigments, indicating that the bracts no longer perform photosynthesis. Contrastingly, genes related to flavonol synthesis are upregulated, providing enhanced defense against UV irradiation damage. Additionally, anatomically abnormal mesophyll combined with the downregulation of genes related to mesophyll differentiation in bracts illustrates the innovation and specification of the glass-like bracts. We further detect substantial accumulation of antifreeze proteins (e.g. AFPs, LEAs) and various metabolites (e.g. Proline, Protective sugars, procyanidins) in over-wintering roots. These findings provide new insights into subnival adaptation and the evolution of glasshouse alpine plants.
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Affiliation(s)
- Ying Li
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Zhimin Niu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Mingjia Zhu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Zhenyue Wang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Renping Xu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Minjie Li
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Zeyu Zheng
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Zhiqiang Lu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Congcong Dong
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Hongyin Hu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Yingbo Yang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Ying Wu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Dandan Wang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Jinli Yang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Jin Zhang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Dongshi Wan
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Richard Abbott
- School of Biology, University of St Andrews, St Andrews, Fife, KY169TH, UK
| | - Jianquan Liu
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China.
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education & State Key Laboratory of Hydraulics & Mountain River Engineering, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
| | - Yongzhi Yang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China.
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Feng T, Pucker B, Kuang T, Song B, Yang Y, Lin N, Zhang H, Moore MJ, Brockington SF, Wang Q, Deng T, Wang H, Sun H. The genome of the glasshouse plant noble rhubarb (Rheum nobile) provides a window into alpine adaptation. Commun Biol 2023; 6:706. [PMID: 37429977 DOI: 10.1038/s42003-023-05044-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 06/14/2023] [Indexed: 07/12/2023] Open
Abstract
Glasshouse plants are species that trap warmth via specialized morphology and physiology, mimicking a human glasshouse. In the Himalayan alpine region, the highly specialized glasshouse morphology has independently evolved in distinct lineages to adapt to intensive UV radiation and low temperature. Here we demonstrate that the glasshouse structure - specialized cauline leaves - is highly effective in absorbing UV light but transmitting visible and infrared light, creating an optimal microclimate for the development of reproductive organs. We reveal that this glasshouse syndrome has evolved at least three times independently in the rhubarb genus Rheum. We report the genome sequence of the flagship glasshouse plant Rheum nobile and identify key genetic network modules in association with the morphological transition to specialized glasshouse leaves, including active secondary cell wall biogenesis, upregulated cuticular cutin biosynthesis, and suppression of photosynthesis and terpenoid biosynthesis. The distinct cell wall organization and cuticle development might be important for the specialized optical property of glasshouse leaves. We also find that the expansion of LTRs has likely played an important role in noble rhubarb adaptation to high elevation environments. Our study will enable additional comparative analyses to identify the genetic basis underlying the convergent occurrence of glasshouse syndrome.
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Affiliation(s)
- Tao Feng
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Boas Pucker
- Department of Plant Sciences, University of Cambridge, Tennis Court Road, Cambridge, CB2 3EA, UK
- CeBiTec & Faculty of Biology, Bielefeld University, Universitaetsstrasse, Bielefeld, 33615, Germany
- Institute of Plant Biology & BRICS, TU Braunschweig, 38106, Braunschweig, Germany
| | - Tianhui Kuang
- CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Bo Song
- CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Ya Yang
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, St. Paul, MN, 55108, USA
| | - Nan Lin
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Huajie Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Michael J Moore
- Department of Biology, Oberlin College, Oberlin, OH, 44074, USA
| | - Samuel F Brockington
- Department of Plant Sciences, University of Cambridge, Tennis Court Road, Cambridge, CB2 3EA, UK
| | - Qingfeng Wang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China
| | - Tao Deng
- CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
| | - Hengchang Wang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China.
| | - Hang Sun
- CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
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Xu YW, Sun L, Ma R, Gao YQ, Sun H, Song B. Does pollinator dependence decrease along elevational gradients? PLANT DIVERSITY 2023; 45:446-455. [PMID: 37601546 PMCID: PMC10435910 DOI: 10.1016/j.pld.2023.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/15/2023] [Accepted: 03/19/2023] [Indexed: 08/22/2023]
Abstract
Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments. However, recent research has yet to consistently support the generality of this expectation. In this study, we asked whether pollinator dependence decreases along an elevational gradient and how it varies with various reproductive traits. To answer these questions, we quantified pollinator-plant associations and various reproductive traits for 112 flowering plants spanning a large elevational gradient (990-4260 m a.s.l.) in the Qinghai-Tibet Plateau. We found that flowering plants in the Qinghai-Tibet Plateau region are highly dependent on pollinators for seed production (76.2% of seed production was contributed by animal pollinators and 44.6% of plants would produce no seed without pollinator visitation). Contrary to our expectation, there was no significant elevational gradient in pollinator dependence index. Although the pollinator dependence index was not significantly correlated with pollen limitation, flower size, floral longevity, or reward type, it was correlated with compatibility status and flowering time. These findings indicate that pollinator dependence does not decrease along an elevational gradient in the Qinghai-Tibet Plateau. Our study also highlights the severe vulnerability of flowering plant seed production to pollinator declines under global change in the Qinghai-Tibet Plateau region, particularly for early-flowering or self-incompatible plants growing at higher elevations (e.g., subnival belt).
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Affiliation(s)
- Yue-Wen Xu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Lu Sun
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Rong Ma
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Yong-Qian Gao
- Yunnan Forestry Technological College, Kunming 650224, China
| | - Hang Sun
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Bo Song
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
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Raguso RA. Hidden worlds within flowers. Curr Biol 2023; 33:R506-R512. [PMID: 37279684 DOI: 10.1016/j.cub.2023.04.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There is a growing realization that ecological interactions take place at many scales, from acorns to forests, and that formerly overlooked community members, particularly microbes, can play outsized ecological roles. Beyond their primary function as the reproductive organs of angiosperms, flowers constitute resource-rich, ephemeral habitats teeming with flower-loving symbionts, or 'anthophiles'. The physical, chemical, and structural properties of flowers combine to create a habitat filter, selectively determining which anthophiles can reside there, and how, and when they interact. The microhabitats within flowers can provide shelter from predators or inclement weather, places to eat, sleep, thermoregulate, hunt, mate or reproduce. In turn, floral microhabitats contain the full range of mutualists, antagonists and apparent commensals, whose complex interactions impact how flowers look and smell, how profitable they are to foraging pollinators, and how selection feeds back upon the traits shaping those interactions. Recent studies suggest coevolutionary paths by which floral symbionts might be co-opted as mutualists and provide compelling examples in which ambush predators or florivores are recruited as floral allies. Unbiased studies that include the full roster of floral symbionts are likely to reveal novel links and additional nuance in the rich ecological communities hidden within flowers.
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Affiliation(s)
- Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
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Lin W, Xu Y, Jiang Y, Ma Z. To cheat or to treat? Fungus gnat pollination in Aspidistra. Ecology 2022; 103:e3729. [PMID: 35419821 DOI: 10.1002/ecy.3729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/26/2022] [Accepted: 03/01/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Wei Lin
- College of Agriculture, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, National Demonstration Center for Experimental Plant Science Education, Guangxi University, Nanning, China
| | - Yuanqing Xu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, China
| | - Yuhui Jiang
- College of Agriculture, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, National Demonstration Center for Experimental Plant Science Education, Guangxi University, Nanning, China
| | - Zhonghui Ma
- College of Agriculture, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, National Demonstration Center for Experimental Plant Science Education, Guangxi University, Nanning, China
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Mhlanga NM, Murphy AM, Wamonje FO, Cunniffe NJ, Caulfield JC, Glover BJ, Carr JP. An Innate Preference of Bumblebees for Volatile Organic Compounds Emitted by Phaseolus vulgaris Plants Infected With Three Different Viruses. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.626851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cucumber mosaic virus (CMV)-infected tomato (Solanum lycopersicum L.) plants emit volatile organic compounds (VOCs) attractive to bumblebees (Bombus terrestris L.), which are important tomato pollinators, but which do not transmit CMV. We investigated if this effect was unique to the tomato-CMV pathosystem. In two bean (Phaseolus vulgaris L.) cultivars, infection with the potyviruses bean common mosaic virus (BCMV) or bean common mosaic necrosis virus (BCMNV), or with the cucumovirus CMV induced quantitative changes in VOC emission detectable by coupled gas chromatography–mass spectrometry. In free-choice olfactometry assays bumblebees showed an innate preference for VOC blends emitted by virus-infected non-flowering bean plants and flowering CMV-infected bean plants, over VOCs emitted by non-infected plants. Bumblebees also preferred VOCs of flowering BCMV-infected plants of the Wairimu cultivar over non-infected plants, but the preference was not significant for BCMV-infected plants of the Dubbele witte cultivar. Bumblebees did not show a significant preference for VOCs from BCMNV-infected flowering bean plants but differential conditioning olfactometric assays showed that bumblebees do perceive differences between VOC blends emitted by flowering BCMNV-infected plants over non-infected plants. These results are consistent with the concept that increased pollinator attraction may be a virus-to-host payback, and show that virus-induced changes in bee-attracting VOC emission is not unique to one virus-host combination.
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Matsumoto TK, Hirobe M, Sueyoshi M, Miyazaki Y. Selective pollination by fungus gnats potentially functions as an alternative reproductive isolation among five Arisaema species. ANNALS OF BOTANY 2021; 127:633-644. [PMID: 33263745 PMCID: PMC8052922 DOI: 10.1093/aob/mcaa204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/01/2020] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Interspecific difference in pollinators (pollinator isolation) is important for reproductive isolation in flowering plants. Species-specific pollination by fungus gnats has been discovered in several plant taxa, suggesting that they can contribute to reproductive isolation. Nevertheless, their contribution has not been studied in detail, partly because they are too small for field observations during flower visitation. To quantify their flower visitation, we used the genus Arisaema (Araceae) because the pitcher-like spathe of Arisaema can trap all floral visitors. METHODS We evaluated floral visitor assemblage in an altitudinal gradient including five Arisaema species. We also examined interspecific differences in altitudinal distribution (geographic isolation) and flowering phenology (phenological isolation). To exclude the effect of interspecific differences in altitudinal distribution on floral visitor assemblage, we established ten experimental plots including the five Arisaema species in high- and low-altitude areas and collected floral visitors. We also collected floral visitors in three additional sites. Finally, we estimated the strength and contribution of these three reproductive barriers using a unified formula for reproductive isolation. KEY RESULTS Each Arisaema species selectively attracted different fungus gnats in the altitudinal gradient, experimental plots and additional sites. Altitudinal distribution and flowering phenology differed among the five Arisaema species, whereas the strength of geographic and phenological isolations were distinctly weaker than those in pollinator isolation. Nevertheless, the absolute contribution of pollinator isolation to total reproductive isolation was weaker than geographic and phenological isolations, because pollinator isolation functions after the two early-acting barriers in plant life history. CONCLUSIONS Our results suggest that selective pollination by fungus gnats potentially contributes to reproductive isolation. Since geographic and phenological isolations can be disrupted by habitat disturbance and interannual climate change, the strong and stable pollinator isolation might compensate for the weakened early-acting barriers as an alternative reproductive isolation among the five Arisaema species.
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Affiliation(s)
- Tetsuya K Matsumoto
- Graduate School of Environmental and Life Science, Okayama University, Kita-ku, Okayama, Japan
- For correspondence. E-mail
| | - Muneto Hirobe
- Graduate School of Environmental and Life Science, Okayama University, Kita-ku, Okayama, Japan
| | - Masahiro Sueyoshi
- Center for Biodiversity, Forestry and Forest Products Research Institute, Tsukuba, Japan
| | - Yuko Miyazaki
- Graduate School of Environmental and Life Science, Okayama University, Kita-ku, Okayama, Japan
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11
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Gao Y, Zheng J, Lin X, Du F. Distribution patterns of clonal plants in the subnival belt of the Hengduan Mountains, SW China. PLANT DIVERSITY 2020; 42:386-392. [PMID: 33134623 PMCID: PMC7584785 DOI: 10.1016/j.pld.2020.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/27/2020] [Accepted: 06/28/2020] [Indexed: 06/11/2023]
Abstract
Clonal reproduction (i.e., production of potentially independent offspring by vegetative growth) is thought to provide plants with reproductive assurance. Thus, studying the evolution of clonal reproduction in local floras is crucial for our understanding of the adaptive mechanisms plants deploy in stressful environments such as alpine regions. In this study, we characterized clonal plant species in the subnival belt of the Hengduan Mountains (a global biodiversity hotspot with extreme environmental conditions in southwest China), in order to determine the effects of sex system, growth form, and elevational distribution on clonality. We compiled clonality data of angiosperm species belonging to 41 families in the subnival belt of the Hengduan Mountains using published information. Of the 793 species recorded in the region, 47.92% (380 species) are clonal species. Both sex system and growth form had significant effects on the occurrence of clonal reproduction: unisexual species (79.79%) were more likely to be clonal than bisexual species (43.63%), and herbaceous species (51.04%) were more likely to be clonal than woody species (16.67%). Compared with non-alpine-endemic species (44.60%), alpine-endemic species (58.33%) showed a significantly higher proportion of clonal reproduction. Further logistic regression analysis showed a positive association between incidence of clonality and elevational range, indicating that species distributed at high elevations are more likely to be clonal. Furthermore, the elevational gradients in clonality were contingent on sex system or growth form. This study reveals that plants in the subnival belt of the Hengduan Mountains might optimize their probability of reproduction through clonal reproduction, a finding that adds to our growing understanding of plant's adaptations to harsh alpine environments.
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Affiliation(s)
- Yongqian Gao
- Faculty of Forestry, Southwest Forestry University, 300 Bailong Road, Kunming, 650224, Yunnan, PR China
- Yunnan Forestry Technological College, 1 Jindian, Kunming, 650224, Yunnan, PR China
| | - Jinxuan Zheng
- Forest Inventory and Planning Institute of Yunnan Province, Kunming, 650051, Yunnan, China
| | - Xiangqun Lin
- Yunnan Forestry Technological College, 1 Jindian, Kunming, 650224, Yunnan, PR China
| | - Fan Du
- Faculty of Forestry, Southwest Forestry University, 300 Bailong Road, Kunming, 650224, Yunnan, PR China
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12
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Proffit M, Lapeyre B, Buatois B, Deng X, Arnal P, Gouzerh F, Carrasco D, Hossaert-McKey M. Chemical signal is in the blend: bases of plant-pollinator encounter in a highly specialized interaction. Sci Rep 2020; 10:10071. [PMID: 32572098 PMCID: PMC7308319 DOI: 10.1038/s41598-020-66655-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 05/14/2020] [Indexed: 11/25/2022] Open
Abstract
In several highly specialized plant-insect interactions, scent-mediated specificity of pollinator attraction is directed by the emission and detection of volatile organic compounds (VOCs). Although some plants engaged in such interactions emit singular compounds, others emit mixtures of VOCs commonly emitted by plants. We investigated the chemical ecological bases of host plant recognition in the nursery pollination mutualism between the dioecious Ficus carica and its specific pollinator Blastophaga psenes. Using Y-tube olfactometer tests, we show that B. psenes females are attracted by VOCs of receptive figs of both sexes and do not exhibit preference for VOCs of either male or female figs. Electrophysiological tests and chemical analysis revealed that of all the VOCs emitted by receptive figs, only five were found to be active on female antennae. Behavioural tests show that, in contrast to VOCs presented alone, only a blend with a particular proportion of four of these VOCs is as attractive as the odour of receptive figs, and that if there is a very small change in this blend proportion, the pollinator is no longer attracted. This study revealed that in highly specialized mutualistic interactions specificity could be mediated by a particular blend of common compounds emitted by plants.
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Affiliation(s)
- Magali Proffit
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France.
| | - Benoit Lapeyre
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Bruno Buatois
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Xiaoxia Deng
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Pierre Arnal
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
| | - Flora Gouzerh
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France.,MIVEGEC, Univ Montpellier, IRD, CNRS, Montpellier, France
| | - David Carrasco
- MIVEGEC, Univ Montpellier, IRD, CNRS, Montpellier, France
| | - Martine Hossaert-McKey
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France
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Villacañas de Castro C, Hoffmeister TS. Friend or foe? A parasitic wasp shifts the cost/benefit ratio in a nursery pollination system impacting plant fitness. Ecol Evol 2020; 10:4220-4232. [PMID: 32489591 PMCID: PMC7246216 DOI: 10.1002/ece3.6190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/16/2020] [Accepted: 02/17/2020] [Indexed: 11/26/2022] Open
Abstract
Nursery pollination systems are species interactions where pollinators also act as fruit/seed herbivores of the plant partner. While the plants depend on associated insects for pollination, the insects depend on the plants' reproductive structures for larval development. The outcome of these interactions is thus placed on a gradient between mutualism and antagonism. Less specialized interactions may fluctuate along this gradient with the ecological context, where natural enemies can play an important role. We studied whether a natural enemy may impact the level of seed consumption of a nursery pollinator and how this in turn may influence individual plant fitness. We used the plant Silene latifolia, its herbivore Hadena bicruris, and its ectoparasitoid Bracon variator as a model plant-herbivore-natural enemy system. We investigated seed output, germination, survival, and flower production as proxies for individual plant fitness. We show that B. variator decreases the level of seed consumption by H. bicruris larvae which in turn increased seed output in S. latifolia plants, suggesting that parasitism by B. variator may act as a regulator in the system. However, our results also show that plant survival and flower production decrease with higher seed densities, and therefore, an increase in seed output may be less beneficial for plant fitness than estimated from seed output alone. Our study should add another layer to the complex discussion of whether parasitoids contribute to plant fitness, as we show that taking simple proxies such as seed output is insufficient to determine the net effect of multitrophic interactions.
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Affiliation(s)
| | - Thomas S. Hoffmeister
- Population and Evolutionary Ecology GroupInstitute of EcologyFB 02University of BremenBremenGermany
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14
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De Medeiros BAS, Núñez-Avellaneda LA, Hernandez AM, Farrell BD. Flower visitors of the licuri palm (Syagrus coronata): brood pollinators coexist with a diverse community of antagonists and mutualists. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Bruno A S De Medeiros
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology Harvard University, Cambridge, MA, USA
| | | | - Alyssa M Hernandez
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology Harvard University, Cambridge, MA, USA
| | - Brian D Farrell
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology Harvard University, Cambridge, MA, USA
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15
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Proffit M, Bessière JM, Schatz B, Hossaert-McKey M. Can fine-scale post-pollination variation of fig volatile compounds explain some steps of the temporal succession of fig wasps associated with Ficus racemosa? ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2018. [DOI: 10.1016/j.actao.2017.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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16
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Mochizuki K, Kawakita A. Pollination by fungus gnats and associated floral characteristics in five families of the Japanese flora. ANNALS OF BOTANY 2018; 121:651-663. [PMID: 29300811 PMCID: PMC5853022 DOI: 10.1093/aob/mcx196] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 12/13/2017] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Pollination by fungus gnats (Mycetophilidae and Sciaridae) is uncommon, but is nevertheless known to occur in 20 genera among eight angiosperm families. Because many fungus gnat-pollinated plants possess a dark red floral display, we hypothesized that fungus gnat pollination is more widespread among plants with similar floral display than currently known. We thus studied the pollination biology of flowers with dark red pigmentation in five families, focusing particularly on plants having small, flat, actinomorphic flowers with exposed nectaries and short stamens, because these floral characteristics mirror those of a known fungus gnat-pollinated genus (Mitella). METHODS We observed daytime and night-time floral visitors for a total of 194.5 h in Aucuba japonica (Garryaceae), Euonymus spp. (Celastraceae), Disanthus cercidifolius (Hamamelidaceae), Micranthes fusca (Saxifragaceae) and Streptopus streptopoides (Liliaceae). Visitors were categorized into functional groups, and a pollination importance index (PII) was calculated for each functional group based on visitation frequency, pollen load and behaviour on flowers. KEY RESULTS Fungus gnats were dominant among the 1762 insects observed (36-92 % depending on the plant species) and were the most important pollinators among all plants studied (PII: 0.529-1). Fungus gnat visits occurred during the daytime and, more frequently, at dusk. Most often, pollen grains became clumped on the ventral side of the head and/or thorax as the short-proboscid fungus gnats foraged on nectar and came into contact with anthers located close to the flower base. CONCLUSIONS Pollination by fungus gnats is probably more common than previously thought, especially in habitats similar to those of the plants studied (moist forest understorey, streamside or subalpine meadow) where fungus gnats are abundant year-round. Our results further suggest that there may be a previously unnoticed association between fungus gnat pollination and dark red coloration, and a shared overall floral architecture among the plants studied.
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Affiliation(s)
- Ko Mochizuki
- Center for Ecological Research, Kyoto University, Otsu, Shiga, Japan
- For correspondence. E-mail:
| | - Atsushi Kawakita
- Center for Ecological Research, Kyoto University, Otsu, Shiga, Japan
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18
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Suetsugu K. Independent recruitment of a novel seed dispersal system by camel crickets in achlorophyllous plants. THE NEW PHYTOLOGIST 2018; 217:828-835. [PMID: 29120037 DOI: 10.1111/nph.14859] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 09/23/2017] [Indexed: 05/26/2023]
Abstract
The seeds of most heterotrophic plants, commonly referred to as dust seeds, are typically dispersed in the air like dust particles. Therefore, little attention has been paid to how seeds of heterotrophic plants are dispersed, owing to the notion that wind dispersal is the dominant strategy. However, inconspicuous but fleshy, indehiscent fruit can be observed in distantly related plants that have independently evolved full heterotrophy. Here I investigated the seed dispersal system in three unrelated fully heterotrophic plants with fleshy, indehiscent fruits (Yoania amagiensis, Monotropastrum humile and Phacellanthus tubiflorus) by direct observation, a differential exclusion experiment of fruit feeders and investigation on seed viability through the digestive tract. The present study revealed that camel crickets are the major seed disperser in three achlorophyllous plants in the study population. This represents the first evidence of seed dispersal by camel crickets in any angiosperm species. These heterotrophic plants grow in the understorey of densely vegetated forests where wind is probably an ineffective seed dispersal agent. Life-history traits of the achlorophyllous plants associated with heterotrophic lifestyles, such as colonization of dark understorey habitats and dust seeds, could facilitate independent recruitment of the novel endozoochorous seed dispersal system by camel crickets.
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Affiliation(s)
- Kenji Suetsugu
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan
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Song B, Stöcklin J, Gao YQ, Peng DL, Sun H. Host specificity of two pollinating seed-consuming fly species is not related to soil moisture of host plant in the high Himalayas. Ecol Evol 2017; 7:780-789. [PMID: 28116072 PMCID: PMC5243778 DOI: 10.1002/ece3.2644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/05/2016] [Accepted: 11/08/2016] [Indexed: 11/18/2022] Open
Abstract
Studying the drivers of host specificity can contribute to our understanding of the origin and evolution of obligate pollination mutualisms. The preference–performance hypothesis predicts that host plant choice of female insects is related mainly to the performance of their offspring. Soil moisture is thought to be particularly important for the survival of larvae and pupae that inhabit soil. In the high Himalayas, Rheum nobile and R. alexandrae differ in their distribution in terms of soil moisture; that is, R. nobile typically occurs in scree with well‐drained soils, R. alexandrae in wetlands. The two plant species are pollinated by their respective mutualistic seed‐consuming flies, Bradysia sp1. and Bradysia sp2. We investigated whether soil moisture is important for regulating host specificity by comparing pupation and adult emergence of the two fly species using field and laboratory experiments. Laboratory experiments revealed soil moisture did have significant effects on larval and pupal performances in both fly species, but the two fly species had similar optimal soil moisture requirements for pupation and adult emergence. Moreover, a field reciprocal transfer experiment showed that there was no significant difference in adult emergence for both fly species between their native and non‐native habitats. Nevertheless, Bradysia sp1., associated with R. nobile, was more tolerant to drought stress, while Bradysia sp2., associated with R. alexandrae, was more tolerant to flooding stress. These results indicate that soil moisture is unlikely to play a determining role in regulating host specificity of the two fly species. However, their pupation and adult emergence in response to extremely wet or dry soils are habitat‐specific.
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Affiliation(s)
- Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asian Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China
| | - Jürg Stöcklin
- Institute of Botany University of Basel Basel Switzerland
| | - Yong-Qian Gao
- Yunnan Forestry Technological College Kunming Yunnan China
| | - De-Li Peng
- Key Laboratory for Plant Diversity and Biogeography of East Asian Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asian Kunming Institute of Botany Chinese Academy of Sciences Kunming Yunnan China
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20
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Peng DL, Song B, Yang Y, Niu Y, Sun H. Overlapping Leaves Covering Flowers in the Alpine Species Eriophyton wallichii (Lamiaceae): Key Driving Factors and Their Potential Impact on Pollination. PLoS One 2016; 11:e0164177. [PMID: 27716786 PMCID: PMC5055289 DOI: 10.1371/journal.pone.0164177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 09/21/2016] [Indexed: 11/18/2022] Open
Abstract
Extrafloral structures are supposed to have evolved to protect flowers from harsh physical environments but might have effects on pollination. Overlapping leaves cover flowers in Eriophyton wallichii, an alpine perennial endemic to the Himalaya-Hengduan Mountains. In previous study, it has showed that these extrafloral leaves can protect interior flowers from temperature fluctuations caused by drastic solar radiation fluctuations, but these leaves may also protect interior flowers from rain wash and UVB damage, and we do not know which one is the main function. In this study, we investigated whether rain and UVB protection are the main functions of overlapping leaves covering flowers and their potential impact on pollination. We first measured the intensities of UVB radiation in open air, beneath leaves and corollas, and then examined pollen susceptibility to different intensities of UVB and rain in the laboratory to estimate whether corollas per se protect interior pollen from UVB and rain damage. We also carried out pollination treatments and observed pollinator visitation of flowers with and without leaves in the field to assess whether the overlapping leaves covering flowers impair pollinator attraction. Our results showed that (1) water and strong UVB significantly decreased pollen germinability, but corollas per se could protect pollen from UVB and rain damage; (2) no autonomous self-pollination and apomixis occurred, and pollinators were essential for the reproduction of E. wallichii; however, flower coverage by overlapping leaves did not limit pollination. We suggested that rain and UVB protection was not the main function of overlapping leaves covered flowers, given that this protection can be provided by corollas per se. Alternatively, this extrafloral structure in E. wallichii may have evolved in response to extreme high temperatures associated with the strong solar radiation fluctuations. This indicates that, even in alpine plants, extreme high temperature may affect the evolution of plant extrafloral structures.
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Affiliation(s)
- De-Li Peng
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yang Yang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yang Niu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- * E-mail: (YN); (HS)
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- * E-mail: (YN); (HS)
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21
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Svensson GP, Raguso RA, Flatz R, Smith CI. Floral scent of Joshua trees (Yucca brevifolia sensu lato): Divergence in scent profiles between species but breakdown of signal integrity in a narrow hybrid zone. AMERICAN JOURNAL OF BOTANY 2016; 103:1793-1802. [PMID: 27578627 DOI: 10.3732/ajb.1600033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/13/2016] [Indexed: 05/14/2023]
Abstract
PREMISE OF THE STUDY The role of floral scent in facilitating reproductive isolation between closely related plants remains poorly understood. Yucca brevifolia and Yucca jaegeriana are pollinated by different moth species in allopatry, but in a narrow contact zone, pollinator-host specificity breaks down, resulting in hybridization between species. We explored the chemical basis for reproductive isolation and hybridization in these Joshua trees by characterizing the floral scent of each species in allopatry, analyzing scent profiles from trees in the contact zone, and matching these data with genotypic and phenotypic data. METHODS We analyzed floral volatiles using gas chromatography-mass spectrometry, tested for species divergence of scent profiles and classified trees in the contact zone as hybrid or either parental species. We used floral and vegetative morphological data and genotypic data to classify trees and analyzed whether certain trait combinations were more correlated than others with respect to assignment of trees and whether frequencies of classified tree types differed depending on which data set was used. KEY RESULTS The Joshua tree floral scent included oxygenated 8-carbon compounds not reported for other yuccas. The two species differed (P < 0.001) in scent profiles. In the contact zone, many hybrids were found, and phenotypic traits were generally weakly correlated, which may be explained by extensive gene flow between species or by exposure to different selection pressures. CONCLUSIONS Although the two Joshua tree species produce distinct floral scent profiles, it is insufficient to prevent attraction of associated pollinators to both hosts. Instead, floral morphology may be the key trait mediating gene flow between species.
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Affiliation(s)
- Glenn P Svensson
- Department of Biology, Lund University, Solvegatan 37, SE-22362 Lund Sweden
| | - Robert A Raguso
- Department of Neurobiology and Behavior, 215 Tower Road, Cornell University, Ithaca, New York 14853 USA
| | - Ramona Flatz
- Department of Biology, Willamette University, 900 State Street, Salem, Oregon 97301 USA
| | - Christopher I Smith
- Department of Biology, Willamette University, 900 State Street, Salem, Oregon 97301 USA
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Song B, Stöcklin J, Gao YQ, Peng DL, Song MS, Sun H. Oviposition by mutualistic seed-consuming pollinators reduces fruit abortion in a recently discovered pollination mutualism. Sci Rep 2016; 6:29886. [PMID: 27418228 PMCID: PMC4945934 DOI: 10.1038/srep29886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/23/2016] [Indexed: 11/08/2022] Open
Abstract
A prerequisite for the evolutionary stability of pollinating seed-consuming mutualisms is that each partner benefits from the association. However, few studies of such mutualism have considered the benefit gained by the pollinators. Here, we determined how the pollinating seed-predators ensure the provisioning of their offspring in the recently discovered mutualism between Rheum nobile and Bradysia flies. The correlation between flower fate and fly oviposition was examined. Floral traits and patterns of variation in fruit abortion and fly oviposition were investigated to determine whether female flies exhibit preferences for particular flowers when laying eggs. Indole-3-acetic acid (IAA) was quantified to determine whether female flies manipulate host physiology. Flowers that flies oviposited on had a significantly lower probability of fruit abortion compared with intact flowers. Females did not exhibit oviposition preference for any of the floral traits examined. There was no significant correlation between fruit abortion and fly oviposition in terms of either flower position or timing of flowering. IAA concentrations in oviposited flowers were significantly higher than in intact flowers. Our results suggest that oviposition by the mutualistic seed-consuming pollinator Bradysia sp., greatly reduces the probability of fruit abortion of its host, R. nobile; this may be attributed to the manipulation of host physiology through regulating IAA levels.
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Affiliation(s)
- Bo Song
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Jürg Stöcklin
- Institute of Botany, University of Basel, Schönbeinstr 6, Basel 4056, Switzerland
| | - Yong-Qian Gao
- Yunnan Forestry Technological College, 1 Chuanjin Road, Kunming 650224, Yunnan, PR China
| | - De-Li Peng
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Min-Shu Song
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
| | - Hang Sun
- Key Laboratory for Plant Diversity and Biogeography of East Asian, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, Yunnan, PR China
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Zhang FP, Yang QY, Wang G, Zhang SB. Multiple functions of volatiles in flowers and leaves of Elsholtzia rugulosa (Lamiaceae) from southwestern China. Sci Rep 2016; 6:27616. [PMID: 27278713 PMCID: PMC4899794 DOI: 10.1038/srep27616] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/23/2016] [Indexed: 11/15/2022] Open
Abstract
Although the roles of volatile compounds have been examined separately in plant–herbivore or plant–pollinator interactions, few studies have focused on how plant scents can attract effective pollinators, repel ineffective pollinators, and defend against attacks by insect herbivores. We explored the functional significance of volatile compounds that impart a strong odor to Elsholtzia rugulosa, a shrub species in southwestern China. We monitored the pollinating honey bee Apis cerana, as well as two occasional visitors – Vespa velutina and a Bombus sp. – and an herbivorous beetle Oxycetonia jocunda. Behavior experiments using Y-tubes showed that honey bees were attracted primarily by floral scent while hornets and bumble bees were repelled by both the flowers and leaves. Analysis via gas chromatography-mass spectrometry revealed that these tissue types differed in their compositions and relative amounts of volatile compounds. When the plants were damaged, the average relative amounts of Elsholtzia ketone rapidly increased in the flowers and leaves. Furthermore, herbivorous beetles were strongly repelled by damaged tissues, suggesting a potential defense signaling function by these compounds. Our findings again demonstrate that scents have multiple functions in the interactions among plants and insects.
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Affiliation(s)
- Feng-Ping Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.,Yunnan Key Laboratory for Research and Development of Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
| | - Qiu-Yun Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.,Yunnan Key Laboratory for Research and Development of Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
| | - Gang Wang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Shi-Bao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.,Yunnan Key Laboratory for Research and Development of Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
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Kessler A. Introduction to a Virtual Special Issue on plant volatiles. THE NEW PHYTOLOGIST 2016; 209:1333-1337. [PMID: 26840247 DOI: 10.1111/nph.13854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
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Borges RM. On the Air: Broadcasting and Reception of Volatile Messages in Brood-Site Pollination Mutualisms. SIGNALING AND COMMUNICATION IN PLANTS 2016. [DOI: 10.1007/978-3-319-33498-1_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Martos F, Cariou ML, Pailler T, Fournel J, Bytebier B, Johnson SD. Chemical and morphological filters in a specialized floral mimicry system. THE NEW PHYTOLOGIST 2015; 207:225-234. [PMID: 25704464 DOI: 10.1111/nph.13350] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
Many plant species attract insect pollinators through chemical mimicry of their oviposition sites, often detaining them in a trap chamber that ensures pollen transfer. These plant mimics are considered to be unspecialized at the pollinator species level, yet field observations of a mycoheterotrophic rainforest orchid (Gastrodia similis), which emits an odour reminiscent of rotting fruit, indicate that it is pollinated by a single drosophilid fly species (Scaptodrosophila bangi). We investigated the roles of floral volatiles and the dimensions of the trap chamber in enforcing this specialization, using gas chromatography-mass spectrometry analyses, bioassays and scanning electron microscopy. We showed that G. similis flowers predominantly emit three fatty-acid esters (ethyl acetate, ethyl isobutyrate and methyl isobutyrate) that were shown in experiments to attract only Scaptodrosophila flies. We additionally showed that the trap chamber, which flies enter into via a touch-sensitive 'trapdoor', closely matches the body size of the pollinator species S. bangi and plays a key role in pollen transfer. Our study demonstrates that specialization in oviposition site mimicry is due primarily to volatile chemistry and is reflected in the dimensions of the trapping apparatus. It also indicates that mycoheterotrophic plants can be specialized both on mycorrhizal fungi and insect pollinators.
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Affiliation(s)
- Florent Martos
- School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa
| | - Marie-Louise Cariou
- Evolution, Génomes et Spéciation, UPR 9034, CNRS, Avenue de la Terrasse, Bâtiment 13, BP1, 91198, Gif-sur-Yvette Cedex, France
| | - Thierry Pailler
- Peuplements Végétaux et Bio agresseurs en Milieu Tropical, UMR C53, Université de La Réunion, Avenue René Cassin, 97715, Saint Denis Cedex, La Réunion
| | - Jacques Fournel
- Peuplements Végétaux et Bio agresseurs en Milieu Tropical, UMR C53, Université de La Réunion, Avenue René Cassin, 97715, Saint Denis Cedex, La Réunion
| | - Benny Bytebier
- School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa
| | - Steven D Johnson
- School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa
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