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Claudel C, Loiseau O, Silvestro D, Lev-Yadun S, Antonelli A. Patterns and drivers of heat production in the plant genus Amorphophallus. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:874-894. [PMID: 37340521 DOI: 10.1111/tpj.16343] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 04/26/2023] [Accepted: 06/01/2023] [Indexed: 06/22/2023]
Abstract
Thermogenesis - the ability to generate metabolic heat - is much more common in animals than in plants, but it has been documented in several plant families, most prominently the Araceae. Metabolic heat is produced in floral organs during the flowering time (anthesis), with the hypothesised primary functions being to increase scent volatilisation for pollinator attraction, and/or to provide a heat reward for invertebrate pollinators. Despite in-depth studies on the thermogenesis of single species, no attempts have yet been made to examine plant thermogenesis across an entire clade. Here, we apply time-series clustering algorithms to 119 measurements of the full thermogenic patterns in inflorescences of 80 Amorphophallus species. We infer a new time-calibrated phylogeny of this genus and use phylogenetic comparative methods to investigate the evolutionary determinants of thermogenesis. We find striking phenotypic variation across the phylogeny, with heat production in multiple clades reaching up to 15°C, and in one case 21.7°C above ambient temperature. Our results show that the thermogenic capacity is phylogenetically conserved and is also associated with inflorescence thickness. Our study paves the way for further investigations of the eco-evolutionary benefits of thermogenesis in plants.
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Affiliation(s)
- Cyrille Claudel
- Institute for Plant Science and Microbiology, Department of Biology, University of Hamburg, Ohnhorststraße 18, 22609, Hamburg, Germany
| | - Oriane Loiseau
- School of GeoSciences, King's Buildings, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Daniele Silvestro
- Gothenburg Global Biodiversity Centre, Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland
- Swiss Institute of Bioinformatics (SIB), 1015, Lausanne, Switzerland
| | - Simcha Lev-Yadun
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa-Oranim, Tivon, 36006, Israel
| | - Alexandre Antonelli
- Gothenburg Global Biodiversity Centre, Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK
- Department of Biology, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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2
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Koyamatsu D, Otsubo M, Ohira T, Sato MP, Suzuki-Masuko H, Shiota T, Takenaka Takano K, Ozeki M, Otsuka K, Ogura Y, Hayashi T, Watanabe M, Inaba T, Ito-Inaba Y. Molecular characterization of SrSTP14, a sugar transporter from thermogenic skunk cabbage, and its possible role in developing pollen. PHYSIOLOGIA PLANTARUM 2023; 175:e13957. [PMID: 37338180 DOI: 10.1111/ppl.13957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 06/21/2023]
Abstract
In floral thermogenesis, sugars play an important role not only as energy providers but also as growth and development facilitators. Yet, the mechanisms underlying sugar translocation and transport in thermogenic plants remain to be studied. Asian skunk cabbage (Symplocarpus renifolius) is a species that can produce durable and intense heat in its reproductive organ, the spadix. Significant morphological and developmental changes in the stamen are well-characterized in this plant. In this study, we focused on the sugar transporters (STPs), SrSTP1 and SrSTP14, whose genes were identified by RNA-seq as the upregulated STPs during thermogenesis. Real-time PCR confirmed that mRNA expression of both STP genes was increased from the pre-thermogenic to the thermogenic stage in the spadix, where it is predominantly expressed in the stamen. SrSTP1 and SrSTP14 complemented the growth defects of a hexose transporter-deficient yeast strain, EBY4000, on media containing 0.02, 0.2, and 2% (w/v) glucose and galactose. Using a recently developed transient expression system in skunk cabbage leaf protoplasts, we revealed that SrSTP1 and SrSTP14-GFP fusion proteins were mainly localized to the plasma membrane. To dig further into the functional analysis of SrSTPs, tissue-specific localization of SrSTPs was investigated by in situ hybridization. Using probes for SrSTP14, mRNA expression was observed in the microspores within the developing anther at the thermogenic female stage. These results indicate that SrSTP1 and SrSTP14 transport hexoses (e.g., glucose and galactose) at the plasma membrane and suggest that SrSTP14 may play a role in pollen development through the uptake of hexoses into pollen precursor cells.
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Affiliation(s)
- Daiki Koyamatsu
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Miyabi Otsubo
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Tomonori Ohira
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Mitsuhiko P Sato
- Department of Frontier Research and Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | | | - Takuya Shiota
- Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki, Japan
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Kohei Takenaka Takano
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Masaaki Ozeki
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Koichi Otsuka
- Natural Environment Division, Nagano Environmental Conservation Research Institute, Nagano, Japan
| | - Yoshitoshi Ogura
- Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Fukuoka, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masao Watanabe
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Yasuko Ito-Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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3
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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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Terry I. Pollination: Multimodal signaling in a co-dependent thermogenic gymnosperm system. Curr Biol 2023; 33:R353-R356. [PMID: 37160091 DOI: 10.1016/j.cub.2023.03.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Plant-pollinator interaction research commonly focuses on more apparent traits, floral morphology and odor. A new study of a thermogenic gymnosperm brood-site pollination system via a specialist beetle reveals intricate long- and short-range multimodal signals are involved in host finding.
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Affiliation(s)
- Irene Terry
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA.
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5
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Salzman S, Dahake A, Kandalaft W, Valencia-Montoya WA, Calonje M, Specht CD, Raguso RA. Cone humidity is a strong attractant in an obligate cycad pollination system. Curr Biol 2023; 33:1654-1664.e4. [PMID: 37015222 DOI: 10.1016/j.cub.2023.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 04/05/2023]
Abstract
Studies of pollination biology often focus on visual and olfactory aspects of attraction, with few studies addressing behavioral responses and morphological adaptation to primary metabolic attributes. As part of an in-depth study of obligate nursery pollination of cycads, we find that Rhopalotria furfuracea weevils show a strong physiological response and behavioral orientation to the cone humidity of the host plant Zamia furfuracea in an equally sensitive manner to their responses to Z. furfuracea-produced cone volatiles. Our results demonstrate that weevils can perceive fine-scale differences in relative humidity (RH) and that individuals exhibit a strong behavioral preference for higher RH in binary choice assays. Host plant Z. furfuracea produces a localized cloud of higher than ambient humidity around both pollen and ovulate cones, and R. furfuracea weevils preferentially land at the zone of maximum humidity on ovulate cones, i.e., the cracks between rows of megasporophylls that provide access to the ovules. Moreover, R. furfuracea weevils exhibit striking antennal morphological traits associated with RH perception, suggesting the importance of humidity sensing in the evolution of this insect lineage. Results from this study suggest that humidity functions in a signal-like fashion in this highly specialized pollination system and help to characterize a key pollination-mediating trait in an ancient plant lineage.
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Affiliation(s)
- Shayla Salzman
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA; School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY 14853, USA.
| | - Ajinkya Dahake
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - William Kandalaft
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - Wendy A Valencia-Montoya
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| | | | - Chelsea D Specht
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY 14853, USA
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
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6
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Wang R, Chen L, Jia Y, Liu L, Sun L, Liu Y, Li Y. Heat production and volatile biosynthesis are linked via alternative respiration in Magnolia denudata during floral thermogenesis. FRONTIERS IN PLANT SCIENCE 2022; 13:955665. [PMID: 36311085 PMCID: PMC9614359 DOI: 10.3389/fpls.2022.955665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Floral thermogenesis is coupled with odor emission in known thermogenic plants. It is widely accepted that elevation in floral temperature can help release of volatile organic compounds (VOCs). However, no information is available about whether floral thermogenesis is associated with VOC biosynthesis. Here, we used RNA-Sequencing (RNA-Seq) to draw a gene expression atlas of floral thermogenesis in Magnolia denudata and captured an upregulation of Alternative Oxidase (AOX) during floral thermogenesis. Western blot analyses also suggested upregulation of AOX during floral thermogenesis. Moreover, oxygen consumption analyses revealed increased activity of the AOX respiration pathway during floral thermogenesis. Using HPLC analyses, we further found that increased AOX respiration substantially promoted production of citric acid by 1.35 folds, which provided fundamental metabolite skeletons for biosynthesis of VOCs. RNA-Seq also showed upregulation of genes regulating lignin catabolism, which was in agreement with in situ Raman chemical imaging of lignin. Taken together, our results suggest the central role of AOX by coupling heat production and VOC biosynthesis in floral thermogenesis of M. denudata.
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Affiliation(s)
- Ruohan Wang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Ling Chen
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Yaping Jia
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Liya Liu
- Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Liwei Sun
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Yujun Liu
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Yun Li
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
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7
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Roemer RB, Irene Terry L, Booth DT, Walter GH. Insights from an ancient gymnosperm lineage: ambient temperature and light and the timing of thermogenesis in cycad cones. AMERICAN JOURNAL OF BOTANY 2022; 109:151-165. [PMID: 35025111 DOI: 10.1002/ajb2.1810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/08/2021] [Indexed: 06/14/2023]
Abstract
PREMISE Although maintaining the appropriate mid-day timing of the diel thermogenic events of cones of the dioecious cycads Macrozamia lucida and M. macleayi is central to the survival of both plant and pollinator in this obligate pollination mutualism, the nature of the underlying mechanism remains obscure. We investigated whether it is under circadian control. Circadian mechanisms control the timing of many ecologically important processes in angiosperms, yet only a few gymnosperms have been studied in this regard. METHODS We subjected cones to different ambient temperature and lighting regimens (constant temperature and darkness; stepwise cool/warm ambient temperatures in constant darkness; stepwise dark/light exposures at constant temperature) to determine whether the resulting timing of their thermogenic events was consistent with circadian control. RESULTS Cones exposed to constant ambient temperature and darkness generated multiple temperature peaks endogenously, with an average interpeak-temperature period of 20.7 (±0.20) h that is temperature-compensated (Q10 = 1.02). Exposure to 24-h ambient temperature cycles (12 h cool/12 h warm, constant darkness) yielded an interpeak-temperature period of 24.0 (±0.05) h, accurately and precisely replicating the ambient temperature period. Exposure to 24-h photo-cycles (12 h light/12 h dark, constant ambient temperature) yielded a shorter, more variable interpeak-temperature period of 23 (±0.23) h. CONCLUSIONS Our results indicate that cycad cone thermogenesis is under circadian clock control and differentially affected by ambient temperature and light cycles. Our data from cycads (an ancient gymnosperm lineage) adds to what little is known about circadian timing in gymnosperms, which have rarely been studied from the circadian perspective.
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Affiliation(s)
- Robert B Roemer
- Department of Mechanical Engineering, University of Utah, 1543 Rio Tinto Kennecott Mechanical Engineering Bldg., 1495 E., 100 S., Salt Lake City, UT, 84112, USA
| | - L Irene Terry
- School of Biological Sciences, University of Utah, 257 S. 1400 E., Salt Lake City, UT, 84112, USA
| | - David T Booth
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Gimme H Walter
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia
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Moré M, Soteras F, Ibañez AC, Dötterl S, Cocucci AA, Raguso RA. Floral Scent Evolution in the Genus Jaborosa (Solanaceae): Influence of Ecological and Environmental Factors. PLANTS (BASEL, SWITZERLAND) 2021; 10:1512. [PMID: 34451557 PMCID: PMC8398055 DOI: 10.3390/plants10081512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/05/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Floral scent is a key communication channel between plants and pollinators. However, the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a 'warm Lowland Subtropical nectar-rewarding clade' with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a 'cool-temperate brood-deceptive clade' of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across "pollinator climates" (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.
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Affiliation(s)
- Marcela Moré
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Florencia Soteras
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Ana C. Ibañez
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Stefan Dötterl
- Department of Biosciences, Paris-Lodron-University of Salzburg, 5020 Salzburg, Austria;
| | - Andrea A. Cocucci
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Robert A. Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
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Affiliation(s)
- Alicia Toon
- School of Biological Sciences; The University of Queensland; Brisbane Queensland 4072 Australia
| | - L. Irene Terry
- School of Biological Sciences; University of Utah; Salt Lake City Utah USA
| | | | - Gimme H. Walter
- School of Biological Sciences; The University of Queensland; Brisbane Queensland 4072 Australia
| | - Lyn G. Cook
- School of Biological Sciences; The University of Queensland; Brisbane Queensland 4072 Australia
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10
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Salzman S, Crook D, Crall JD, Hopkins R, Pierce NE. An ancient push-pull pollination mechanism in cycads. SCIENCE ADVANCES 2020; 6:eaay6169. [PMID: 32582845 PMCID: PMC7292639 DOI: 10.1126/sciadv.aay6169] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 04/17/2020] [Indexed: 05/25/2023]
Abstract
Most cycads engage in brood-site pollination mutualisms, yet the mechanism by which the Cycadales entice pollination services from diverse insect mutualists remains unknown. Here, we characterize a push-pull pollination mechanism between a New World cycad and its weevil pollinators that mirrors the mechanism between a distantly related Old World cycad and its thrips pollinators. The behavioral convergence between weevils and thrips, combined with molecular phylogenetic dating and a meta-analysis of thermogenesis and coordinated patterns of volatile attraction and repulsion suggest that a push-pull pollination mutualism strategy is ancestral in this ancient, dioecious plant group. Hence, it may represent one of the earliest insect/plant pollination mechanisms, arising long before the evolution of visual floral signaling commonly used by flowering plants.
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Affiliation(s)
- Shayla Salzman
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- The Arnold Arboretum, Harvard University, Boston, MA 02131, USA
- Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Damon Crook
- USDA-APHIS-PPQ CPHST, Otis Laboratory, Building 1398, Otis ANGB, MA 02542, USA
| | - James D. Crall
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Robin Hopkins
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- The Arnold Arboretum, Harvard University, Boston, MA 02131, USA
| | - Naomi E. Pierce
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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Suinyuy TN, Johnson SD. Geographic variation in cone volatiles and pollinators in the thermogenic African cycad Encephalartos ghellinckii Lem. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:579-590. [PMID: 29281847 DOI: 10.1111/plb.12685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/19/2017] [Indexed: 06/07/2023]
Abstract
Heat and odour production can have profound effects on pollination in cycads. It is therefore expected that these traits would co-vary geographically with pollinator assemblages. Such intraspecific variation, may lead to the evolution of pollination ecotypes, which can be an early stage of pollinator-mediated speciation. We measured cone temperatures using miniature temperature data loggers and examined the composition of cone volatile odours using headspace sampling and analysis with gas chromatography-mass spectrometry in four populations spanning the range of the African cycad Encephalartos ghellinckii. Pollinator assemblages were also investigated in three populations. Male and female cones were thermogenic at pollen shed and receptive stages, respectively, but patterns of thermogenesis did not vary among populations. Scent emissions from cones in populations in the Drakensberg Mountains were characterised by cis-β-ocimene, β-myrcene and (3E)-1,3-octadiene, while camphene and α-pinene were characteristic of scent emissions from cones in populations closer to the coast. These differences in volatile blends corresponded with differences in insect assemblages. These results confirm intraspecific variation in volatile emissions of E. ghellinckii and support the predictions that intraspecific variation in volatile emissions will be associated with shifts in pollinator assemblages. While further work needs to be done to test for local adaptation in this system, this preliminary evidence is consistent with the formation of pollination ecotypes in the E. ghellinckii species complex.
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Affiliation(s)
- T N Suinyuy
- School of Life Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, South Africa
| | - S D Johnson
- School of Life Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, South Africa
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