1
|
Balbuena MS, Buchmann SL, Papaj DR, Raguso RA. Organ-specific volatiles from Sonoran desert Krameria flowers as potential signals for oil-collecting bees. PHYTOCHEMISTRY 2024; 218:113937. [PMID: 38035972 DOI: 10.1016/j.phytochem.2023.113937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/21/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
The evolution of flowers that offer oils as rewards and are pollinated by specialized bees represents a distinctive theme in plant-pollinator co-diversification. Some plants that offer acetylated glycerols as floral oils emit diacetin, a volatile by-product of oil metabolism, which is utilized by oil-collecting bees as an index signal for the presence of floral oil. However, floral oils in the genus Krameria (Krameriaceae) contain β-acetoxy-substituted fatty acids instead of acetylated glycerols, making them unlikely to emit diacetin as an oil-bee attractant. We analyzed floral headspace composition from K. bicolor and K. erecta, native to the Sonoran Desert of southwestern North America, in search of alternative candidates for volatile index signals. Using solid-phase microextraction, combined with gas chromatography-mass spectrometry, we identified 26 and 45 floral volatiles, respectively, from whole flowers and dissected flower parts of these two Krameria species. As expected, diacetin was not detected. Instead, β-ionone emerged as a strong candidate for an index signal, as it was uniquely present in dissected oil-producing floral tissues (elaiophores) of K. bicolor, as well as the larval cells and provisions from its oil-bee pollinator, Centris cockerelli. This finding suggests that the floral oil of K. bicolor is perfused with β-ionone in its tissue of origin and retains the distinctive raspberry-like scent of this volatile after being harvested by C. cockerelli bees. In contrast, the elaiophores of K. erecta, which are not thought to be pollinated by C. cockerelli, produced a blend of anise-related oxygenated aromatics not found in the elaiophores of K. bicolor. Our findings suggest that β-ionone has the potential to impact oil-foraging by C. cockerelli bees through several potential mechanisms, including larval imprinting on scented provisions or innate or learned preferences by foraging adults.
Collapse
Affiliation(s)
- Maria Sol Balbuena
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA.
| | - Stephen L Buchmann
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA.
| | - Daniel R Papaj
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA.
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
2
|
Lipińska MM, Olędrzyńska N, Dudek M, Naczk AM, Łuszczek D, Szabó P, Speckmaier M, Szlachetko DL. Characters evolution of Encyclia (Laeliinae-Orchidaceae) reveals a complex pattern not phylogenetically determined: insights from macro- and micromorphology. BMC PLANT BIOLOGY 2023; 23:661. [PMID: 38124025 PMCID: PMC10731901 DOI: 10.1186/s12870-023-04664-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
Encyclia is the second-largest genus in the neotropical subtribe Laeliinae (Orchidaceae) and has more than 150 species, which are characterized by fairly consistent flower morphology. Its taxonomy and species boundaries, however, seem to be still under debate. In the present study, we first examined the lip micromorphology of 61 species of Encyclia sensu stricto. We correlated our results with external flower morphology and phylogenetic analyses performed on a combined dataset that included both nuclear (ITS, Xdh, PhyC) and plastid markers (ycf1, rpl32, and trnL-trnF). Phylogenetic reconstruction showed that Encyclia sensu stricto species form a coherent, monophyletic group. However, it is difficult to determine the relationships between the different groups within one larger clade. The groups all form distinct lineages that evolved from a common ancestor. The UPGMA cluster analysis for the seven qualitative micromorphological features clearly divides the genus into two main groups, the larger of which is further subdivided into two subgroups. None of these, however, overlap with any of the phylogeographic units distinguished in previously published papers or in presented article. It is worth noting that the groups resulting from the UPGMA analysis cannot be defined by macromorphological features. The pattern of similarities between species, taking into account both macro- and micromorphological features, is eminently mosaic in nature, and only a multifaceted approach can explain this enigmatic group.
Collapse
Affiliation(s)
- Monika M Lipińska
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland
- Foundation Polish Orchid Association, Sopot, 81825, Poland
| | - Natalia Olędrzyńska
- Department of Evolutionary Genetics and Biosystematics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland
| | - Magdalena Dudek
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland
| | - Aleksandra M Naczk
- Department of Evolutionary Genetics and Biosystematics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland.
| | - Dorota Łuszczek
- Laboratory of Electron Microscopy, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland
| | - Peter Szabó
- Individual Researcher, Vasvár, 9800, Hungary
| | - Manfred Speckmaier
- Botanischer Garten, Universität Wien, Rennweg 14/2, Raum G-10, Vienna, 1030, Austria
| | - Dariusz L Szlachetko
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, Gdańsk, 80308, Poland
| |
Collapse
|
3
|
Perkins J, Hayashi T, Peakall R, Flematti GR, Bohman B. The volatile chemistry of orchid pollination. Nat Prod Rep 2023; 40:819-839. [PMID: 36691832 DOI: 10.1039/d2np00060a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Covering: up to September 2022Orchids are renowned not only for their diversity of floral forms, but also for their many and often highly specialised pollination strategies. Volatile semiochemicals play a crucial role in the attraction of a wide variety of insect pollinators of orchids. The compounds produced by orchid flowers are as diverse as the pollinators they attract, and here we summarise some of the chemical diversity found across orchid taxa and pollination strategies. We focus on compounds that have been experimentally demonstrated to underpin pollinator attraction. We also highlight the structural elucidation and synthesis of a select subset of important orchid pollinator attractants, and discuss the ecological significance of the discoveries, the gaps in our current knowledge of orchid pollination chemistry, and some opportunities for future research in this field.
Collapse
Affiliation(s)
- James Perkins
- Research School of Biology, The Australian National University, Australia
| | - Tobias Hayashi
- Research School of Biology, The Australian National University, Australia
| | - Rod Peakall
- Research School of Biology, The Australian National University, Australia.,School of Molecular Sciences, The University of Western Australia, Australia
| | - Gavin R Flematti
- School of Molecular Sciences, The University of Western Australia, Australia
| | - Björn Bohman
- Research School of Biology, The Australian National University, Australia.,School of Molecular Sciences, The University of Western Australia, Australia.,Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Sweden.
| |
Collapse
|
4
|
Bazzicalupo M, Calevo J, Smeriglio A, Cornara L. Traditional, Therapeutic Uses and Phytochemistry of Terrestrial European Orchids and Implications for Conservation. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12020257. [PMID: 36678970 PMCID: PMC9863304 DOI: 10.3390/plants12020257] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 06/12/2023]
Abstract
The Orchidaceae family accounts for about 28,000 species, and most of them are mentioned in the folk medicine of nations around the world. The use of terrestrial orchids in European and Mediterranean regions has been reported since ancient times, but little information is available on their medicinal properties, as well as on their phytochemicals and biological activities. However, plant collection for human use is still listed as one of the main threats for terrestrial orchids, alongside other menacing factors such as wrong habitat management and disturbance to symbionts, such as pollinators and mycorrhizal fungi. Therefore, the primary aim of this review was to resume and discuss available information regarding the past and current popular uses of European orchids. We then grouped phytochemical data to evaluate the presence of bioactive compounds of pharmacological relevance, and we discussed whether these could support the therapeutic employment of the different organs. Finally, we briefly debated the sustainability of orchid utilizations, considering the different threatening factors and conservation actions including plant propagation methods.
Collapse
Affiliation(s)
- Miriam Bazzicalupo
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, 16132 Genova, Italy
- CREA—Research Centre for Vegetable and Ornamental Crops, Council for Agricultural Research and Economics, 18038 Sanremo, Italy
| | - Jacopo Calevo
- Department of Ecosystem Stewardship, Jodrell Laboratory, Royal Botanic Gardens, KEW, Richmond, Surrey TW9 3DS, UK
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Antonella Smeriglio
- Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, 98166 Messina, Italy
| | - Laura Cornara
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, 16132 Genova, Italy
| |
Collapse
|
5
|
Zhang D, Zhao XW, Li YY, Ke SJ, Yin WL, Lan S, Liu ZJ. Advances and prospects of orchid research and industrialization. HORTICULTURE RESEARCH 2022; 9:uhac220. [PMID: 36479582 PMCID: PMC9720451 DOI: 10.1093/hr/uhac220] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/22/2022] [Indexed: 06/17/2023]
Abstract
Orchidaceae is one of the largest, most diverse families in angiosperms with significant ecological and economical values. Orchids have long fascinated scientists by their complex life histories, exquisite floral morphology and pollination syndromes that exhibit exclusive specializations, more than any other plants on Earth. These intrinsic factors together with human influences also make it a keystone group in biodiversity conservation. The advent of sequencing technologies and transgenic techniques represents a quantum leap in orchid research, enabling molecular approaches to be employed to resolve the historically interesting puzzles in orchid basic and applied biology. To date, 16 different orchid genomes covering four subfamilies (Apostasioideae, Vanilloideae, Epidendroideae, and Orchidoideae) have been released. These genome projects have given rise to massive data that greatly empowers the studies pertaining to key innovations and evolutionary mechanisms for the breadth of orchid species. The extensive exploration of transcriptomics, comparative genomics, and recent advances in gene engineering have linked important traits of orchids with a multiplicity of gene families and their regulating networks, providing great potential for genetic enhancement and improvement. In this review, we summarize the progress and achievement in fundamental research and industrialized application of orchids with a particular focus on molecular tools, and make future prospects of orchid molecular breeding and post-genomic research, providing a comprehensive assemblage of state of the art knowledge in orchid research and industrialization.
Collapse
Affiliation(s)
- Diyang Zhang
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xue-Wei Zhao
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuan-Yuan Li
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shi-Jie Ke
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wei-Lun Yin
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Siren Lan
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhong-Jian Liu
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| |
Collapse
|
6
|
The Floral Signals of the Inconspicuous Orchid Malaxis monophyllos: How to Lure Small Pollinators in an Abundant Environment. BIOLOGY 2022; 11:biology11050640. [PMID: 35625368 PMCID: PMC9137910 DOI: 10.3390/biology11050640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 12/04/2022]
Abstract
Simple Summary Malaxis monophyllos is an ephemeral orchid with very small, greenish flowers, whose pollination system remains vague. Therefore, the authors aimed to identify the flower’s features, including its anatomical micro and ultrastructure as well as scent biochemistry, which are involved in attracting pollinators. In this paper, the authors established the variety of emissions of M. monophyllos volatile compounds, with a high proportion of aldehydes and aliphatic alcohols, listed as chemicals that induce a pronounced reaction in Diptera. Second, the entire M. monophyllos labellum exhibits metabolic and secretory activity, which can be related to both emission of volatiles and visual attractants but also to the nutritional reward for pollinators. All these flower features indicated that its pollination system is dedicated to dipterans, with few signaling modalities corresponding to deceptive species (brood site and food decoy) but also referring to rewarding ones (nutritional secretion, fungus/microbe reward). This research reveals a few new issues in M. monophyllos pollination biology that provides new scientific areas for in-depth insights in the future. Abstract Many orchid species have evolved complex floral signals to ensure pollination efficiency. Here, the authors combined analyses of anatomical flower structure with analyses of the volatile composition and flower-visiting insects’ behaviour, as well as characterised features that can attract pollinators of the inconspicuous orchid Malaxis monophyllos. During field observations, the authors found that only small Diptera (e.g., mosquitos, drosophilids, fungus gnats) visit and are interested in the flowers of M. monophyllos, which was reflected in the characterised flower features that combine well with the pollination system, which engages dipterans. Analyses of the M. monophyllos floral scent revealed substantial concentrations of aliphatic compounds, e.g., 1-octen-3-ol and 1-octanol, which condition the mushroom-like scent and a substantial fraction of alkanes, some of which have been previously described as sex mimicry and aggregation pheromones in orchids’ deceptive systems. The labellum anatomical structure exhibits a highly diverse cell cuticle surface and pronounced metabolic and secretory activity of the epidermal and subepidermal cells from all parts of the labellum. Moreover, our study provides evidence for the subsequent decoys of M. monophyllos flowers, including visual signals, such as raphides located on the labellum margin and the rewarding ones connected with lipid secretion limited to the area behind the column. Taking an integrative approach to studying M. monophyllos pollination biology, the authors provide new insight into its previously vague pollination strategies and provide evidence for complex floral signal operation in luring potential pollinators. The synergistic effect of M. monophyllos flowers’ volatile and visual signals, together with additional rewarding for nectar/fungus/microbe-feeding pollinators, requires further detailed investigation that will be invaluable in explaining the evolution of Diptera-specific pollination systems in orchids.
Collapse
|
7
|
Robustelli della Cuna FS, Cortis P, Esposito F, De Agostini A, Sottani C, Sanna C. Chemical Composition of Essential Oil from Four Sympatric Orchids in NW-Italy. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11060826. [PMID: 35336708 PMCID: PMC8948801 DOI: 10.3390/plants11060826] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 06/12/2023]
Abstract
Orchidaceae is a flowering plant family worldwide distributed known for producing volatile organic compounds (VOCs) which can act as olfactory signals for pollinators. Despite the importance of VOCs in the different reproductive strategies, in the literature there are only a few publications on the characterization of orchids' volatile profiles. In this study, the essential oils from fresh inflorescences of sympatric orchids Anacamptis morio, Himantoglossum robertianum, Ophrys sphegodes and Orchis purpurea, naturally growing in Piedmont (Italy) were isolated by steam distillation and characterized by GC/FID and GC/MS. A number of compounds were identified, with a peculiar distribution in the species: alcohols (range 16.93-50.60%), from which p-cresol (range 12.75-38.10%) was the most representative compound; saturated hydrocarbons (range 5.81-59.29%), represented by pentacosane (range 2.22-40.17%) and tricosane (range 0.78-27.48%); long-chain monounsaturated hydrocarbons (range 0.29-5.20%) represented by 9-pentacosene, 11-tricosene, and 1-heneicosene. The structure of positional isomers in linear alkenes was elucidated by derivatization with dimethyl disulfide and MS fragmentation patterns. Coumarin (68.84%) was the dominant compound in O. purpurea and was detected in lower concentrations (range 0.21-0.26%) in the other taxa. These volatile compounds may represent a particular feature of these plant species and play an essential role in pollinator interaction.
Collapse
Affiliation(s)
- Francesco Saverio Robustelli della Cuna
- Department of Drug Sciences, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy;
- Casimiro Mondino National Neurological Institute, Via Mondino 2, 27100 Pavia, Italy
| | - Pierluigi Cortis
- Department of Life and Environmental Sciences, University of Cagliari, Via S. Ignazio da Laconi 13, 09123 Cagliari, Italy; (A.D.A.); (C.S.)
| | - Fabiana Esposito
- Agroecology Lab, Université libre de Bruxelles, 1050 Brussels, Belgium;
| | - Antonio De Agostini
- Department of Life and Environmental Sciences, University of Cagliari, Via S. Ignazio da Laconi 13, 09123 Cagliari, Italy; (A.D.A.); (C.S.)
| | - Cristina Sottani
- Environmental Research Center, ICS MAUGERI SPA SB, Institute of Pavia, IRCCS, 27100 Pavia, Italy;
| | - Cinzia Sanna
- Department of Life and Environmental Sciences, University of Cagliari, Via S. Ignazio da Laconi 13, 09123 Cagliari, Italy; (A.D.A.); (C.S.)
- Co. S. Me. Se—Consorzio per lo Studio dei Metaboliti Secondari, Via Sant’Ignazio da Laconi 13, 09123 Cagliari, Italy
| |
Collapse
|
8
|
Bersweden L, Viruel J, Schatz B, Harland J, Gargiulo R, Cowan RS, Calevo J, Juan A, Clarkson JJ, Leitch AR, Fay MF. Microsatellites and petal morphology reveal new patterns of admixture in Orchis hybrid zones. AMERICAN JOURNAL OF BOTANY 2021; 108:1388-1404. [PMID: 34418070 DOI: 10.1002/ajb2.1710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/20/2021] [Accepted: 02/23/2021] [Indexed: 05/23/2023]
Abstract
PREMISE The genetic structure of hybrid zones provides insight into the potential for gene flow to occur between plant taxa. Four closely related European orchid species (Orchis anthropophora, O. militaris, O. purpurea, and O. simia) hybridize when they co-occur. We aimed to characterize patterns of hybridization in O. militaris-O. purpurea, O. purpurea-O. simia, and O. anthropophora-O. simia hybrid zones using molecular and morphological data. METHODS We used 11 newly isolated nuclear microsatellites to genotype 695 individuals collected from seven hybrid zones and six allopatric parental populations in France. Geometric morphometric analysis was conducted using 15 labellum landmarks to capture the main aspects of petal shape. RESULTS Backcrossing was asymmetric toward O. militaris in multiple O. militaris-O. purpurea hybrid zones. Hybrids in O. purpurea-O. simia and O. anthropophora-O. simia hybrid zones were largely limited to F1 and F2 generations, but further admixture had occurred. These patterns were reflected in labellum geometric morphometric data, which correlated strongly with nuclear microsatellite data in all three species combinations. CONCLUSIONS The coexistence of parental and admixed individuals in these Orchis hybrid zones implies they are likely to be tension zones being maintained by a balance between gene flow into the hybrid zone and selection acting against admixed individuals. The pattern of admixture in the three species combinations suggests intrinsic selection acting on the hybrids is weaker in more closely related taxa.
Collapse
Affiliation(s)
- Leif Bersweden
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Juan Viruel
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
| | - Bertrand Schatz
- Centre for Ecology and Evolution, University of Montpellier, Montpellier 34090, France
| | - Joanna Harland
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | | | - Robyn S Cowan
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
| | - Jacopo Calevo
- Department of Life Sciences and Systems Biology, University of Turin, Turin 10125, Italy
| | - Ana Juan
- Department of Environmental Sciences & Natural Resources, University of Alicante, San Vicente, Alicante 03690, Spain
| | | | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Michael F Fay
- Jodrell Laboratory, Royal Botanic Gardens, Kew TW9 3DS, UK
- School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia
| |
Collapse
|
9
|
Trunschke J, Lunau K, Pyke GH, Ren ZX, Wang H. Flower Color Evolution and the Evidence of Pollinator-Mediated Selection. FRONTIERS IN PLANT SCIENCE 2021; 12:617851. [PMID: 34381464 PMCID: PMC8350172 DOI: 10.3389/fpls.2021.617851] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 05/14/2021] [Indexed: 06/01/2023]
Abstract
The evolution of floral traits in animal-pollinated plants involves the interaction between flowers as signal senders and pollinators as signal receivers. Flower colors are very diverse, effect pollinator attraction and flower foraging behavior, and are hypothesized to be shaped through pollinator-mediated selection. However, most of our current understanding of flower color evolution arises from variation between discrete color morphs and completed color shifts accompanying pollinator shifts, while evidence for pollinator-mediated selection on continuous variation in flower colors within populations is still scarce. In this review, we summarize experiments quantifying selection on continuous flower color variation in natural plant populations in the context of pollinator interactions. We found that evidence for significant pollinator-mediated selection is surprisingly limited among existing studies. We propose several possible explanations related to the complexity in the interaction between the colors of flowers and the sensory and cognitive abilities of pollinators as well as pollinator behavioral responses, on the one hand, and the distribution of variation in color phenotypes and fitness, on the other hand. We emphasize currently persisting weaknesses in experimental procedures, and provide some suggestions for how to improve methodology. In conclusion, we encourage future research to bring together plant and animal scientists to jointly forward our understanding of the mechanisms and circumstances of pollinator-mediated selection on flower color.
Collapse
Affiliation(s)
- Judith Trunschke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Klaus Lunau
- Institute of Sensory Ecology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Graham H. Pyke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Department of Biological Sciences, Macquarie University, Ryde, NSW, Australia
| | - Zong-Xin Ren
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| |
Collapse
|
10
|
Aguiar JMRBV, Ferreira GDS, Sanches PA, Bento JMS, Sazima M. What pollinators see does not match what they smell: Absence of color-fragrance association in the deceptive orchid Ionopsis utricularioides. PHYTOCHEMISTRY 2021; 182:112591. [PMID: 33333335 DOI: 10.1016/j.phytochem.2020.112591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/13/2020] [Accepted: 11/14/2020] [Indexed: 06/12/2023]
Abstract
Many deceptive orchids present variation in floral color and fragrance. This might be advantageous for the plant, as it can disturb the associative avoidance learning of pollinators, promoting more visits to the flowers. Some studies have shown that color and fragrance can be correlated in polymorphic deceptive orchids, but these studies employed color traits based on the human visual system and not the visual perception of pollinators. Thus, we investigated the composition of the floral fragrance of Ionopsis utricularioides (Sw.) Lindl., a polymorphic deceptive orchid, and analyzed possible correlations with the floral color as seen by bees, Apis mellifera L. and Melipona quadrifasciata Lepeletier, using the color hexagon model. We found high color and fragrance intraspecific variation, as expected for deceptive species. However, we found no color-fragrance association in individuals, either by comparing fragrance profiles with the color variable saturation or by comparing them with the placement of individuals in the color hexagon for both bee species. This lack of correlation contradicts the biochemical pathway hypothesis, which proposes that associations between floral color and scent in polymorphic flowers arise from shared biochemical pathways. However, a complete absence of correlation between floral signals is consistent with selection arising through pollinator cognitive ecology. Lack of correlation would increase the floral variability perceived by bees, given their multimodal learning, and this variability could disrupt avoidance learning of deceptive flowers, thus enhancing the efficacy of the plant's deceptive pollination mechanism.
Collapse
Affiliation(s)
| | - Gabriel de Souza Ferreira
- Senckenberg Centre for Human Evolution and Palaeoenvironment (HEP) at the Eberhard Karls Universität Tübingen, Sigwartstr. 10, 72076, Tübingen, Germany
| | - Patricia Alessandra Sanches
- Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Departamento de Entomologia e Acarologia, Piracicaba, SP, 13418-900, Brazil; Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092, Zürich, Switzerland
| | - José Mauricio Simões Bento
- Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Departamento de Entomologia e Acarologia, Piracicaba, SP, 13418-900, Brazil
| | - Marlies Sazima
- Departamento de Botânica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, 13083-865, Brazil
| |
Collapse
|
11
|
Capó M, Borràs J, Perelló-Suau S, Rita J, Cursach J. Ecological factors affecting the fitness of the threatened orchid Anacamptis robusta (Orchidaceae): Habitat disturbance, interactions with a co-flowering rewarding orchid and hybridization events. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:121-129. [PMID: 32896978 DOI: 10.1111/plb.13179] [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: 07/16/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
The food-deceptive species Anacamptis robusta is threatened in the Balearic Islands, and its habitat has recently been transformed through human disturbance. This study investigated how human disturbance affects the reproductive output of A. robusta and how its fitness is affected by competition with rewarding relatives, fungal infections and hybridization processes. To evaluate the impact of habitat loss on plant fitness, data on reproductive measures were obtained in two well-conserved subpopulations and the unique disturbed subpopulation. Photo-trapping cameras were installed to determine the floral visitation rate. All flowering individuals in 2019 were georeferenced using differential GPS to examine the influence of geospatial patterns on the reproductive success of A. robusta. In addition, hand-pollination treatments were performed to evaluate the hybridization between A. coriophora and A. robusta and the origin of A. × albuferensis. The human-disturbed subpopulation of A. robusta had a lower fruit set success than the subpopulations in well-conserved areas. The presence of A. coriophora is negatively affecting the reproductive output of A. robusta. Moreover, A. robusta can only act as the pollen donor during hybridization. The complexity of the ecological system, which is enhanced by the strong pollinator dependence of the threatened species, must be considered when making conservation decisions. Although human disturbance directly affects plant population stability, other ecological issues must be considered, such as pollinator interaction, interspecific competition for pollinators, fungal infection and hybridization events.
Collapse
Affiliation(s)
- M Capó
- Laboratory of Botany, Research Group on Plant Biology under Mediterranean Conditions, Department of Biology, University of Balearic Islands, Palma, Spain
| | - J Borràs
- Laboratory of Botany, Research Group on Plant Biology under Mediterranean Conditions, Department of Biology, University of Balearic Islands, Palma, Spain
| | - S Perelló-Suau
- Laboratory of Botany, Research Group on Plant Biology under Mediterranean Conditions, Department of Biology, University of Balearic Islands, Palma, Spain
| | - J Rita
- Laboratory of Botany, Research Group on Plant Biology under Mediterranean Conditions, Department of Biology, University of Balearic Islands, Palma, Spain
| | - J Cursach
- Laboratory of Botany, Research Group on Plant Biology under Mediterranean Conditions, Department of Biology, University of Balearic Islands, Palma, Spain
| |
Collapse
|
12
|
D’Auria M, Fascetti S, Racioppi R, Romano VA, Rosati L. Orchids from Basilicata: The Scent. ACTA ACUST UNITED AC 2020. [DOI: 10.1007/978-3-030-11257-8_32-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
|
13
|
Bao T, Shadrack K, Yang S, Xue X, Li S, Wang N, Wang Q, Wang L, Gao X, Cronk Q. Functional Characterization of Terpene Synthases Accounting for the Volatilized-Terpene Heterogeneity in Lathyrus odoratus Cultivar Flowers. PLANT & CELL PHYSIOLOGY 2020; 61:1733-1749. [PMID: 32726442 DOI: 10.1093/pcp/pcaa100] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Lathyrus odoratus (sweet pea) is an ornamental plant with exceptional floral scent, previously used as an experimental organism in the early development of Mendelian genetics. However, its terpene synthases (TPSs), which act as metabolic gatekeepers in the biosynthesis of volatile terpenoids, remain to be characterized. Auto-Headspace Solid-phase Microextraction/Gas chromatography-mass spectrometry analysis of floral volatile terpene constituents from seven sweet pea cultivars identified α-bergamotene, linalool, (-)-α-cubebene, geraniol, β-caryophyllene and β-sesquiphellandrene as the dominant compounds. RNA sequencing was performed to profile the transcriptome of L. odoratus flowers. Bioinformatic analysis identified eight TPS genes (acronymed as LoTPS) that were successfully cloned, heterologously expressed and functionally analyzed. LoTPS4 and LoTPS7, belonging to the TPS-b clade, biochemically catalyzed the formation of monoterpenes and sesquiterpenes. LoTPS3 and LoTPS8, placed in the TPS-a clade, also generated monoterpenes and sesquiterpenes, while LoTPS12 belonging to the TPS-g clade showed linalool/nerolidol synthase activity. Notably, biochemical assays of the recombinant LoTPS proteins revealed their catalytic promiscuity, and the enzymatic products were basically consistent with major volatile compounds released from sweet pea flowers. The data from our study lay the foundation for the chemical ecology, molecular genetics and biotechnological improvement of sweet pea and other legumes (Fabaceae).
Collapse
Affiliation(s)
- Tingting Bao
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Kimani Shadrack
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
- Department of Biological and Physical Sciences, Karatina University, Karatina, Kenya
| | - Song Yang
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Xinxin Xue
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Shuying Li
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Ning Wang
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Qiuyue Wang
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Li Wang
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Xiang Gao
- Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun, China
| | - Quentin Cronk
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
14
|
Shrestha M, Dyer AG, Dorin A, Ren ZX, Burd M. Rewardlessness in orchids: how frequent and how rewardless? PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:555-561. [PMID: 32181557 DOI: 10.1111/plb.13113] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/09/2020] [Indexed: 05/26/2023]
Abstract
About one-third of orchid species are thought to offer no floral reward and therefore attract pollinators through deception. Statements of this idea are common in the botanical literature, but the empirical basis of the estimate is rarely mentioned. We traced citation pathways for the one-third estimate in a sample of the literature and found that the paths lead to empirical foundations that are surprisingly narrow. Moreover, recent measurements have detected minute quantities of sugar available to insect visitors in some orchids thought to be rewardless, raising the possibility of a pollination strategy that is largely deceitful but different to absolute rewardlessness. The orchids are a well-studied group and there is no doubt that rewardlessness is common in the family. However, greater empirical effort is needed to verify rewardlessness in orchids and to explore geographic and environmental variation in the proportion of rewardless species.
Collapse
Affiliation(s)
- M Shrestha
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
- School of Media and Communication, RMIT University, Melbourne, Victoria, Australia
- Faculty of Information Technology, Monash University, Melbourne, Victoria, Australia
| | - A G Dyer
- School of Media and Communication, RMIT University, Melbourne, Victoria, Australia
| | - A Dorin
- Faculty of Information Technology, Monash University, Melbourne, Victoria, Australia
| | - Z-X Ren
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, PR China
| | - M Burd
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
15
|
Abstract
Pollination is the transfer of pollen grains from the stamens to the stigma, an essential requirement of sexual reproduction in flowering plants. Cross-pollination increases genetic diversity and is favored by selection in the majority of situations. Flowering plants have evolved a wide variety of traits that influence pollination success, including those involved in optimization of self-pollination, attraction of animal pollinators, and the effective use of wind pollination. In this review we discuss our current understanding of the molecular basis of the development and production of these various traits. We conclude that recent integration of molecular developmental studies with population genetic approaches is improving our understanding of how selection acts on key floral traits in taxonomically diverse species, and that further work in nonmodel systems promises to provide exciting insights in the years to come.
Collapse
Affiliation(s)
- Róisín Fattorini
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom;
| | - Beverley J Glover
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom;
| |
Collapse
|
16
|
Diversity of Floral Glands and Their Secretions in Pollinator Attraction. REFERENCE SERIES IN PHYTOCHEMISTRY 2020. [DOI: 10.1007/978-3-319-96397-6_48] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
17
|
Wróblewska A, Szczepaniak L, Bajguz A, Jędrzejczyk I, Tałałaj I, Ostrowiecka B, Brzosko E, Jermakowicz E, Mirski P. Deceptive strategy in Dactylorhiza orchids: multidirectional evolution of floral chemistry. ANNALS OF BOTANY 2019; 123:1005-1016. [PMID: 30753414 PMCID: PMC6589506 DOI: 10.1093/aob/mcz003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 01/03/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS The deception strategies of orchids remain poorly understood, especially in regard to the chemical compounds emitted from their flowers and their interaction with various taxonomic groups of pollinators. We investigated the phylogenetic relationships and compared the variation of floral chemical compounds between food-deceptive Dactylorhiza taxa (D. incarnata var. incarnata and D. incarnata var. ochroleuca, D. fuchsii and D. majalis) from populations in north-eastern Poland. We propose a model of the evolution of deception based on floral chemical signals in this genus. METHODS A Bayesian approach based on polymorphic plastid DNA (trnL, trnF and psbC-trnK), internal transcribed spacer (ITS) sequences and flow cytometry data was applied to confirm the taxonomic status of the studied orchids. We also identified and classified the pollinators and flower visitors in each Dactylorhiza population to the taxonomic level and compared our results with literature data. The chemical composition of pentane and diethyl ether extracts from the flowers was analysed by gas chromatography-mass spectrometry. Variation of the floral chemical components was visualized by non-metric multidimensional scaling based on Bray-Curtis dissimilarity. KEY RESULTS The genetic distinctiveness of D. incarnata, D. fuchsii and D. majalis was confirmed. No hybrids between them were found, but the chloroplast DNA (cpDNA), ITS haplotypes and flow cytometry showed genetic similarity between D. incarnata var. incarnata and D. incarnata var. ochroleuca. We determined that Apis mellifera (Hymenoptera) was the only shared pollinator of these taxa. Strangalia attenuata and Alosterna tabacicolor (Coleoptera) and Volucella pellucens and V. bombylans (Hymenoptera) were observed pollinating D. fuchsii. Visualization of the emission rates of the 61 floral chemical compounds detected from pentane extracts (mainly hydrocarbons and aldehydes) and the 51 from diethyl extracts (with abundant groups of benzenoids and non-aromatic acids) strongly differentiated D. incarnata, D. fuchsii and D. majalis, while those of the two varieties of D. incarnata (var. incarnata and var. ochroleuca) were almost identical. CONCLUSIONS While the genetic data clearly supported the distinct lineages of D. incarnata, D. fuchsii and D. majalis, the patterns of emission of their flower chemical compounds were more complex within the series of shared compounds (alkanes and aldehydes) and taxon-specific compounds (benzenoids and esters). Their floral bouquet can influence the sexual, social and feeding behaviour of pollinators in different ways. We observed that the floral chemical compounds attracted both shared and species-specific pollinators to Dactylorhiza, confirming the multidirectional character of floral chemical signals in these food-deceptive taxa. Reduction of species-specific pollination levels in Dactylorhiza orchid taxa may promote hybridization between them.
Collapse
Affiliation(s)
- Ada Wróblewska
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
- For correspondence. E-mail
| | - Lech Szczepaniak
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Chemistry, Białystok, Poland
| | - Andrzej Bajguz
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| | - Iwona Jędrzejczyk
- Laboratory of Molecular Biology and Cytometry, Department of Plant Genetics, Physiology and Biotechnology, UTP University of Science and Technology, Bydgoszcz, Poland
| | - Izabela Tałałaj
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| | - Beata Ostrowiecka
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| | - Emilia Brzosko
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| | - Edyta Jermakowicz
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| | - Paweł Mirski
- University of Bialystok, Faculty of Biology and Chemistry, Institute of Biology, Białystok, Poland
| |
Collapse
|
18
|
Du F, Wang T, Fan JM, Liu ZZ, Zong JX, Fan WX, Han YH, Grierson D. Volatile composition and classification of Lilium flower aroma types and identification, polymorphisms, and alternative splicing of their monoterpene synthase genes. HORTICULTURE RESEARCH 2019; 6:110. [PMID: 31645964 PMCID: PMC6804824 DOI: 10.1038/s41438-019-0192-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/03/2019] [Accepted: 07/24/2019] [Indexed: 05/12/2023]
Abstract
Lily is a well-known ornamental plant with a diversity of fragrant types. Basic information on lily floral scent compounds has been obtained for only a few accessions, and little is known about Lilium aroma types, the terpene synthase genes that may play roles in the production of key volatiles, or the range of monoterpenes that these genes produce. In this study, 41 cultivars were analyzed for volatile emissions, and a total of 46 individual volatile compounds were identified, 16 for the first time in lilies. Lily accessions were classified into six groups according to the composition of major scent components: faint-scented, cool, fruity, musky, fruity-honey, and lily. Monoterpenes were one of the main groups of volatiles identified, and attention was focused on terpene synthase (TPS) genes, which encode enzymes that catalyze the last steps in monoterpene synthesis. Thirty-two candidate monoterpene synthase cDNAs were obtained from 66 lily cultivars, and 64 SNPs were identified. Two InDels were also shown to result from variable splicing, and sequence analysis suggested that different transcripts arose from the same gene. All identified nucleotide substitution sites were highly correlated with the amounts of myrcene emitted, and InDel site 230 was highly correlated with the emission of all major monoterpenoid components, especially (E)-β-ocimene. Heterologous expression of five cDNAs cloned from faint-scented and strong-scented lilies showed that their corresponding enzymes could convert geranyl diphosphate to (E)-β-ocimene, α-pinene, and limonene. The findings from this study provide a major resource for the assessment of lily scent volatiles and will be helpful in breeding of improved volatile components.
Collapse
Affiliation(s)
- Fang Du
- College of Horticulture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Ting Wang
- College of Horticulture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Jun-miao Fan
- College of Horticulture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
- College of Horticulture, Nanjing Agricultural University, 210095 Nangjing, Jiangsu China
| | - Zhi-zhi Liu
- College of Horticulture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Jia-xin Zong
- College of Horticulture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Wei-xin Fan
- Experimental Teaching Center, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Yuan-huai Han
- College of Agriculture, Shanxi Agricultural University, 030801 Taigu, Shanxi China
| | - Donald Grierson
- Plant & Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
- Department of Horticulture, College of Agriculture & Biotechnology, Zhejiang University, 310058 Hangzhou, China
| |
Collapse
|
19
|
Aguiar JMRBV, Roselino AC, Sazima M, Giurfa M. Can honey bees discriminate between floral-fragrance isomers? J Exp Biol 2018; 221:jeb.180844. [DOI: 10.1242/jeb.180844] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022]
Abstract
Many flowering plants present variable complex fragrances, which usually include different isomers of the same molecule. As fragrance is an essential cue for flower recognition by pollinators, we ask if honey bees discriminate between floral-fragrance isomers in an appetitive context. We used the olfactory conditioning of the proboscis extension response (PER), which allows training a restrained bee to an odor paired with sucrose solution. Bees were trained under an absolute (a single odorant rewarded) or a differential conditioning regime (a rewarded vs. a non-rewarded odorant) using four different pairs of isomers. One hour after training, discrimination and generalization between pairs of isomers were tested. Bees trained under absolute conditioning exhibited high generalization between isomers and discriminated only one out of four isomer pairs; after differential conditioning, they learned to differentiate between two out of four pairs of isomers but in all cases generalization responses to the non-rewarding isomer remained high. Adding an aversive taste to the non-rewarded isomer facilitated discrimination of isomers that otherwise seemed non-discriminable, but generalization remained high. Although honey bees discriminated isomers under certain conditions, they achieved the task with difficulty and tended to generalize between them, thus showing that these molecules were perceptually similar to them. We conclude that the presence of isomers within floral fragrances might not necessarily contribute to a dramatic extent to floral odor diversity.
Collapse
Affiliation(s)
- João Marcelo Robazzi Bignelli Valente Aguiar
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Ana Carolina Roselino
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Marlies Sazima
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Martin Giurfa
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
| |
Collapse
|
20
|
Delle-Vedove R, Schatz B, Dufay M. Understanding intraspecific variation of floral scent in light of evolutionary ecology. ANNALS OF BOTANY 2017; 120:1-20. [PMID: 28873948 PMCID: PMC5737645 DOI: 10.1093/aob/mcx055] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 03/29/2017] [Indexed: 05/29/2023]
Abstract
Background and Aims Among the various floral traits involved in pollinator attraction and potentially under selection mediated by pollinators, floral scent/fragrance has been less investigated than other components of floral phenotype. Whether or not pollinator-mediated selection impacts floral scents depends on the heritability of scent/fragrance and the occurrence of some variation within species. Although most studies have investigated how scent varies among species, growing amounts of data are available on variation at the intraspecific level. Methods The results of 81 studies investigating intraspecific variation of floral scents in 132 taxa were reviewed. For each study, whether variation was found in either identity, proportion or absolute quantities of volatile organic compounds (VOCs) was recorded, as well as information with the potential to explain variation, such as methodology, plant origin or pollination biology. Key Results Variation was found for almost all investigated species, both among individuals (among and sometimes within populations) and within individuals across different temporal scales. Cases in which such variation is a possible result of pollinator-mediated selection were analysed, by discussing separately selection related to variation in pollinator identity/behaviour among populations or across time, deceit pollination and sex-specific selection. Not surprisingly, in many cases, pollinator-mediated selection alone does not explain the observed variation in floral scent. This led us to review current knowledge on less investigated factors, such as selection mediated by natural enemies, genetic drift and gene flow, environmental constraints, phylogenetic inertia, or biochemical constraints that could be invoked to explain scent variation. Conclusions This review highlights the great potential of analysing floral scent variation and including it in integrated studies of floral phenotypes. We also have identified the current gaps in our understanding of this complex signal and we propose several methodological and conceptual future directions in this research area.
Collapse
Affiliation(s)
- Roxane Delle-Vedove
- Universite de Lille, CNRS UMR 8198 Evo-Eco-Paleo, 59655 Villeneuve d'Ascq Cedex, France
| | - Bertrand Schatz
- CEFE (Centre d’Ecologie Fonctionnelle et Evolutive), UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier, France
| | - Mathilde Dufay
- Universite de Lille, CNRS UMR 8198 Evo-Eco-Paleo, 59655 Villeneuve d'Ascq Cedex, France
| |
Collapse
|
21
|
Valenta K, Nevo O, Martel C, Chapman CA. Plant attractants: integrating insights from pollination and seed dispersal ecology. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9870-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Mokni RE, Hammami S, Dall'Acqua S, Peron G, Faidi K, Braude JP, Sebei H, Aouni MHE. Chemical Composition, Antioxidant and Cytotoxic Activities of Essential Oil of the Inflorescence of Anacamptis coriophora subsp. fragrans (Orchidaceae) from Tunisia. Nat Prod Commun 2016. [DOI: 10.1177/1934578x1601100640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The chemical composition of the essential oil produced by steam distillation of the inflorescences of naturally growing Anacamptis coriophora (L.) R. M. Bateman, Pridgeon & M. W. Chase subsp. fragrans (Pollini) R. M. Bateman, Pridgeon & M. W. Chase (Orchidaceae) from Kroumiria, north-west Tunisia was studied by GC-MS, which led to the identification of 19 volatile components, representing 97% of the oil. The main constituents were methyl-( E)-p-methoxycinnamate (29.3%), 13-heptadecyn-l-ol (18.6%), 2,5-dimethoxybenzyl alcohol (14.1%) and 4-(1,1,3,3-tetramethylbutyl)-phenol (9.0%). DPPH radical scavenging revealed a weak antioxidant activity. In addition, the antiproliferative effects were evaluated on BxPC3 human pancreatic carcinoma cells and on 2008 human ovarian cancer cells showing significant effect. This is the first report of the chemical composition of essential oils obtained from A coriophora subsp. fragrans inflorescences for North Africa. Further studies are needed to understand fully the possible mechanism of action behind the cytotoxic activity of the essential oil.
Collapse
Affiliation(s)
- Ridha El Mokni
- University of Carthage, Laboratory of Botany and Plant Ecology (SNA-214), Department of Life Sciences, Faculty of Sciences of Bizerte, Jarzouna, 7021, Bizerta, Tunisia
- University of Carthage, Laboratory of Soil Sciences and Environment, Mograne Graduate School of Agriculture, 1121 Mograne, Zaghouan, Tunisia
- University of Jendouba, Silvo-pastoral resources Laboratory, Silvo-Pastoral Institute of Tabarka, BP. 345, 8110-Tabarka, Tunisia
- IRESA, Laboratory of Forest Ecology, I.N.R.G.RF.F, Tunis, Tunisia
| | - Saoussen Hammami
- Research Unit 12-04, Applied Chemistry and Environment, Faculty of Sciences of Monastir, 5000, Monastir, Tunisia
| | - Stefano Dall'Acqua
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo, 5, 35131 Padova, Italy
| | - Gregorio Peron
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo, 5, 35131 Padova, Italy
| | - Khaled Faidi
- Research Unit 12-04, Applied Chemistry and Environment, Faculty of Sciences of Monastir, 5000, Monastir, Tunisia
| | - Jeremy Phillip Braude
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo, 5, 35131 Padova, Italy
| | - Houcine Sebei
- University of Carthage, Laboratory of Soil Sciences and Environment, Mograne Graduate School of Agriculture, 1121 Mograne, Zaghouan, Tunisia
| | - Mohamed Hédi El Aouni
- University of Carthage, Laboratory of Botany and Plant Ecology (SNA-214), Department of Life Sciences, Faculty of Sciences of Bizerte, Jarzouna, 7021, Bizerta, Tunisia
| |
Collapse
|
24
|
Marques I, Jürgens A, Aguilar JF, Feliner GN. Convergent recruitment of new pollinators is triggered by independent hybridization events in Narcissus. THE NEW PHYTOLOGIST 2016; 210:731-742. [PMID: 26738752 DOI: 10.1111/nph.13805] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/11/2015] [Indexed: 06/05/2023]
Abstract
Hybridization can generate new species if some degree of isolation prevents gene flow between the hybrids and their progenitors. The recruitment of novel pollinators by hybrids has been hypothesized to be one way in which such reproductive isolation can be achieved. We tested whether pollinators contributed to isolation between two natural Narcissus hybrids and their progenitors using pollination experiments, observations, plus morphological and floral-volatile measurements. These hybrids share the same maternal but different paternal progenitors. We found that only the hybrids were visited by and pollinated by ants. The two hybrids exceeded their progenitors in floral-tube aperture size and nectar production. The emission of floral volatiles by hybrid plants was not only equal to or higher than the progenitor species, but also contained some new compounds not produced by the progenitors. The recruitment of ants as novel pollinators in the hybrids involved the combination of increased nectar secretion and the production of novel floral scent compounds. A breakdown of chemical defence against ants may also be involved. This study provides support for the hypothesis that the recruitment of novel pollinators can contribute to reproductive isolation between hybrids and their progenitors.
Collapse
Affiliation(s)
- Isabel Marques
- Department of Agricultural and Environmental Sciences, High Polytechnic School of Huesca, University of Zaragoza, C/Carretera de Cuarte Km 1, Huesca, E22071, Spain
- UBC Botanical Garden & Centre for Plant Research and Department of Botany, University of British Columbia, 3529-6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Andreas Jürgens
- School of Life Sciences, University of KwaZulu-Natal, Post Bag X01 Scottsville, Pietermaritzburg, 3209, South Africa
| | | | | |
Collapse
|
25
|
Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid. PLoS One 2016; 11:e0147975. [PMID: 26886766 PMCID: PMC4757410 DOI: 10.1371/journal.pone.0147975] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/11/2016] [Indexed: 12/01/2022] Open
Abstract
Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling.
Collapse
|
26
|
Kagawa K, Takimoto G. Inaccurate Color Discrimination by Pollinators Promotes Evolution of Discrete Color Polymorphism in Food-Deceptive Flowers. Am Nat 2016; 187:194-204. [DOI: 10.1086/684433] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
27
|
Chartier M, Liagre S, Weiss-Schneeweiss H, Kolano B, Bessière JM, Schönenberger J, Gibernau M. Floral traits and pollination ecology of European Arum hybrids. Oecologia 2015; 180:439-51. [DOI: 10.1007/s00442-015-3498-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 10/22/2015] [Indexed: 11/29/2022]
|
28
|
Luca A, Palermo AM, Bellusci F, Pellegrino G. Pollen competition between two sympatric Orchis species (Orchidaceae): the overtaking of conspecific of heterospecific pollen as a reproductive barrier. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:219-225. [PMID: 24889383 DOI: 10.1111/plb.12199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/26/2014] [Indexed: 06/03/2023]
Abstract
The frequency of hybrid formation in angiosperms depends on how and when heterospecific pollen is transferred to the stigma, and on the success of that heterospecific pollen at fertilising ovules. We applied pollen mixtures to stigmas to determine how pollen interactions affect siring success and the frequency of hybrid formation between two species of Mediterranean deceptive orchid. Plants of Orchis italica and O. anthropophora were pollinated with conspecific and heterospecific pollen (first conspecific pollen then heterospecific pollen and vice versa) and molecular analysis was used to check the paternity of the seeds produced. In this pair of Mediterranean orchids, competition between conspecific and heterospecific pollen functions as a post-pollination pre-zygotic barrier limiting the frequency of the formation of hybrids in nature. Flowers pollinated with heterospecific pollen can remain receptive for the arrival of conspecific pollen for a long time. There is always an advantage of conspecific pollen for fruit formation, whether it comes before or after heterospecific pollen, because it overtakes the heterospecific pollen. The conspecific pollen advantage exhibited in O. italica and O. anthropophora is likely to result from the reduced germination of heterospecific pollen or retarded growth of heterospecific pollen tubes in the stigma and ovary. Overall, the results indicate that our hybrid zone represents a phenomenon of little evolutionary consequence, and the conspecific pollen advantage maintains the genetic integrity of the parental species.
Collapse
Affiliation(s)
- A Luca
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy
| | | | | | | |
Collapse
|
29
|
Volatile fingerprint of italian populations of orchids using solid phase microextraction and gas chromatography coupled with mass spectrometry. Molecules 2014; 19:7913-36. [PMID: 24962394 PMCID: PMC6271603 DOI: 10.3390/molecules19067913] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/02/2014] [Accepted: 06/06/2014] [Indexed: 11/17/2022] Open
Abstract
The volatile fraction of Ophrys sphegodes Mill. subsp. sphegodes, Ophrys bertolonii subsp. benacensis (Reisigl) O. Danesch, E. Danasch & Ehrend. and Neotinea tridentata (Scop.) R.M. Bateman, Pridgeon & M.W. Case, three orchid species with different pollinator attraction strategies, sampled in vivo and in situ, were evaluated by headspace solid phase microextraction coupled with gas-chromatography and mass spectrometry. The results were compared with the volatile compounds emitted by flowering plant samples picked from the same populations of orchid species. Hydrocarbons, aldehydes, alcohols and terpenes were the major constituents of “in vivo” orchid scents and some distinctive differences in volatile metabolite composition were observed between Ophrys and Neotinea species. Moreover, the odour bouquets of the picked flowering plant samples were different from the in vivo ones and in particular different proportions of the various terpenes and an increase of α-pinene were observed. In conclusion HS/SPME GCMS proved to be a suitable technique for analyzing and distinguishing the volatile fingerprint of different orchid species, sampled in vivo and in situ in a non-disruptive way, with potentially great advantages for ecophysiological studies of rare and endangered species.
Collapse
|
30
|
Dormont L, Delle-Vedove R, Bessière JM, Schatz B. Floral scent emitted by white and coloured morphs in orchids. PHYTOCHEMISTRY 2014; 100:51-59. [PMID: 24525191 DOI: 10.1016/j.phytochem.2014.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 01/15/2014] [Accepted: 01/17/2014] [Indexed: 06/03/2023]
Abstract
Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined.
Collapse
Affiliation(s)
- L Dormont
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS, 1919 Route de Mende, 34293 Montpellier, France.
| | - R Delle-Vedove
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS, 1919 Route de Mende, 34293 Montpellier, France; Laboratoire de Génétique et Evolution des Populations Végétales (GEPV), Université des Sciences et Technologies de Lille 1, 59655 Villeneuve d'Ascq, France
| | - J-M Bessière
- Ecole Nationale Supérieure de Chimie de Montpellier, Laboratoire de Chimie Appliquée, 8 rue de l'Ecole Normale, 34296 Montpellier, France
| | - B Schatz
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS, 1919 Route de Mende, 34293 Montpellier, France
| |
Collapse
|
31
|
Bischoff M, Jürgens A, Campbell DR. Floral scent in natural hybrids of Ipomopsis (Polemoniaceae) and their parental species. ANNALS OF BOTANY 2014; 113:533-44. [PMID: 24355404 PMCID: PMC3906972 DOI: 10.1093/aob/mct279] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/15/2013] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Floral traits, such as floral volatiles, can contribute to pre-zygotic reproductive isolation by promoting species-specific pollinator foraging. When hybrid zones form, floral traits could also influence post-zygotic isolation. This study examined floral volatiles in parental species and natural hybrids in order to explore potential scent mediation of pre-zygotic and post-zygotic isolation. METHODS Floral bouquets were analysed for the sister species Ipomopsis aggregata and I. tenuituba and their natural hybrids at two contact sites differing in both hybridization rate and temporal foraging pattern of hawkmoth pollinators. Floral volatiles were quantified in diurnal and nocturnal scent samples using gas chromatography-mass spectrometry. KEY RESULTS The bouquets of parental species and hybrids showed qualitative overlap. All flowers emitted similar sets of monoterpenoid, sesquiterpenoid, aliphatic and benzenoid compounds, but separated into groups defined by multivariate analysis of quantitative emissions. The parental species differed most strikingly in the nitrogenous compound indole, which was found almost exclusively in nocturnal bouquets of I. tenuituba. Natural hybrid bouquets were highly variable, and showed emission rates of several compounds that appeared transgressive. However, indole emission rates were intermediate in the hybrids compared with rates in the parents. Volatile bouquets at the contact site with lower hybridization did not show greater species specificity in overall scent emission, but I. tenuituba presented a stronger indole signal during peak hawkmoth activity at that site. CONCLUSIONS The two species of Ipomopsis differed in patterns of floral bouquets, with indole emitted in nocturnal I. tenuituba, but not in I. aggregata. Natural hybrid bouquets were not consistently intermediate between the parents, although hybrids were intermediate in indole emission. The indole signal could potentially serve as a hawkmoth attractant that mediates reproductive isolation both before and after hybrid formation.
Collapse
Affiliation(s)
- Mascha Bischoff
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Road, Ithaca, NY 14853, USA
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | - Andreas Jürgens
- University of KwaZulu-Natal, School of Life Sciences, P. Bag X01 Scottsville, Pietermaritzburg 3209, South Africa
| | - Diane R. Campbell
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| |
Collapse
|
32
|
Wang H, Conchou L, Bessière JM, Cazals G, Schatz B, Imbert E. Flower color polymorphism in Iris lutescens (Iridaceae): biochemical analyses in light of plant-insect interactions. PHYTOCHEMISTRY 2013; 94:123-134. [PMID: 23790644 DOI: 10.1016/j.phytochem.2013.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/13/2013] [Accepted: 05/18/2013] [Indexed: 06/02/2023]
Abstract
We describe a flower color polymorphism in Iris lutescens, a species widespread in the Northern part of the Mediterranean basin. We studied the biochemical basis of the difference between purple and yellow flowers, and explored the ecological and evolutionary consequences of such difference, in particular visual discrimination by insects, a potential link with scent emitted and the association between color and scent. Anthocyanins were found to be present in much greater concentrations in purple flowers than in yellow ones, but the anthocyanin composition did not differ between color morphs. Likewise, no quantitative difference in anthocyanin content was found between vegetative tissues of the two morphs. Floral anthocyanins were dominated by delphinidin 3-O-(p-coumaroylrutinoside)-5-O-glucoside (also called delphanin) and its aliphatic derivatives. Small amounts of delphinidin 3-O-(p-caffeoylrutinoside)-5-O-glucoside and its aliphatic derivatives were also characterized. Based on a description of bumblebees' (one of the main pollinators of I. lutescens) color perception, purple and yellow flowers of I. lutescens could be visually discriminated as blue and blue-green, respectively, and likely by a wide variety of other insects. The overall chemical composition of the scent produced was not significantly different between morphs, being dominated by terpenoids, mainly myrcene, (E)-β-ocimene and limonene. A slight color-scent correlation was nevertheless detected, consistent with the shared biosynthetic origin of both pigments and volatile compounds. Therefore in this species, the difference in the amounts of pigments responsible for flower color difference seems to be the major difference between the two morphs. Pollinators are probably the main selective agent driving the evolution of flower color polymorphism in I. lutescens, which represents a suitable species for investigating how such polymorphism is maintained.
Collapse
Affiliation(s)
- Hui Wang
- Institut des Sciences de l'Évolution de Montpellier (ISEM), UMR 5554 CNRS-Université Montpellier 2, Bâtiment 22, Université Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5, France
| | | | | | | | | | | |
Collapse
|
33
|
Parachnowitsch AL, Raguso RA, Kessler A. Phenotypic selection to increase floral scent emission, but not flower size or colour in bee-pollinated Penstemon digitalis. THE NEW PHYTOLOGIST 2012; 195:667-675. [PMID: 22646058 DOI: 10.1111/j.1469-8137.2012.04188.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Fragrance is a putatively important character in the evolution of flowering plants, but natural selection on scent is rarely studied and thus poorly understood. We characterized floral scent composition and emission in a common garden of Penstemon digitalis from three nearby source populations. We measured phenotypic selection on scent as well as floral traits more frequently examined, such as floral phenology, display size, corolla pigment, and inflorescence height. Scent differed among populations in a common garden, underscoring the potential for scent to be shaped by differential selection pressures. Phenotypic selection on flower number and display size was strong. However, selection favoured scent rather than flower size or colour, suggesting that smelling stronger benefits reproductive success in P. digitalis. Linalool was a direct target of selection and its high frequency in floral-scent bouquets suggests that further studies of both pollinator- and antagonist-mediated selection on this compound would further our understanding of scent evolution. Our results indicate that chemical dimensions of floral display are just as likely as other components to experience selective pressure in a nonspecialized flowering herb. Therefore, studies that integrate visual and chemical floral traits should better reflect the true nature of floral evolutionary ecology.
Collapse
Affiliation(s)
- Amy L Parachnowitsch
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Present address: Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala 752 36, Sweden
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
34
|
Artz DR, Hsu CL, Nault BA. Influence of honey bee, Apis mellifera, hives and field size on foraging activity of native bee species in pumpkin fields. ENVIRONMENTAL ENTOMOLOGY 2011; 40:1144-1158. [PMID: 22251726 DOI: 10.1603/en10218] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to identify bee species active in pumpkin fields in New York and to estimate their potential as pollinators by examining their foraging activity. In addition, we examined whether foraging activity was affected by either the addition of hives of the honey bee, Apis mellifera L., or by field size. Thirty-five pumpkin (Cucurbita spp.) fields ranging from 0.6 to 26.3 ha, 12 supplemented with A. mellifera hives and 23 not supplemented, were sampled during peak flowering over three successive weeks in 2008 and 2009. Flowers from 300 plants per field were visually sampled for bees on each sampling date. A. mellifera, Bombus impatiens Cresson, and Peponapis pruinosa (Say) accounted for 99% of all bee visits to flowers. A. mellifera and B. impatiens visited significantly more pistillate flowers than would be expected by chance, whereas P. pruinosa showed no preference for visiting pistillate flowers. There were significantly more A. mellifera visits per flower in fields supplemented with A. mellifera hives than in fields not supplemented, but there were significantly fewer P. pruinosa visits in supplemented fields. The number of B. impatiens visits was not affected by supplementation, but was affected by number of flowers per field. A. mellifera and P. pruinosa visits were not affected by field size, but B. impatiens visited fewer flowers as field size increased in fields that were not supplemented with A. mellifera hives. Declining A. mellifera populations may increase the relative importance of B. impatiens in pollinating pumpkins in New York.
Collapse
Affiliation(s)
- Derek R Artz
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA.
| | | | | |
Collapse
|
35
|
Juillet N, Salzmann CC, Scopece G. Does facilitating pollinator learning impede deceptive orchid attractiveness? A multi-approach test of avoidance learning. PLANT BIOLOGY (STUTTGART, GERMANY) 2011; 13:570-575. [PMID: 21668597 DOI: 10.1111/j.1438-8677.2010.00421.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
It has often been proposed that nectarless deceptive orchid species exploit naïve pollinators in search of food before they learn to avoid their flowers, and that intraspecific floral trait polymorphism, often noted in this plant group, could prolong the time needed for learning, thus increasing orchid reproductive success. We tested the importance of avoidance learning in a European deceptive orchid, Anacamptis morio, which has been reported to have a highly variable fragrance bouquet among individuals. We used an indirect approach, i.e. we facilitated pollinators' ability to learn to avoid A. morio by adding anisaldehyde to selected inflorescences, a scent compound that is easily perceived by the natural pollinators and produced in large quantities by the closely related, nectar producing Anacamptis coriophora, a species that shares pollinator species with A. morio. In a series of three experiments (in artificial arrays, in natural populations and in bumblebee behavioural observations), we consistently found no difference either of reproductive success of or visitation rates to scent-added versus control inflorescences. We also found that the decrease of reproductive success over time in artificial populations of this deceptive species was not as important as expected. Together, these data suggest that pollinators do not fully learn to avoid deceptive inflorescences, and that pollinator avoidance behaviour alone may explain the lower reproductive success usually found in deceptive orchids. We discuss the possible explanations for this pattern in deceptive orchids, particularly in relation to pollinator cognition and learning abilities. Lastly, in light of our results, the potential for higher average reproductive success in deceptive orchids with high phenotypic variability driven by avoidance learning thus appears to be challenged.
Collapse
Affiliation(s)
- N Juillet
- Dipartimento di Biologia Strutturale e Funzionale, Università degli Studi di Napoli Federico II, Complesso Universitario MSA, via Cinthia 1-80, Naples, Italy.
| | | | | |
Collapse
|
36
|
Delle-Vedove R, Juillet N, Bessière JM, Grison C, Barthes N, Pailler T, Dormont L, Schatz B. Colour-scent associations in a tropical orchid: three colours but two odours. PHYTOCHEMISTRY 2011; 72:735-742. [PMID: 21377705 DOI: 10.1016/j.phytochem.2011.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 02/01/2011] [Accepted: 02/07/2011] [Indexed: 05/30/2023]
Abstract
Colour and scent are the major pollinator attractants to flowers, and their production may be linked by shared biosynthetic pathways. Species with polymorphic floral traits are particularly relevant to study the joint evolution of floral traits. We used in this study the tropical orchid Calanthe sylvatica from Réunion Island. Three distinct colour varieties are observed, presenting lilac, white or purple flowers, and named respectively C. sylvaticavar.lilacina (hereafter referred as var. lilacina), C. sylvaticavar. alba (var. alba) and C. sylvatica var. purpurea (var. purpurea). We investigated the composition of the floral scent produced by these colour varieties using the non-invasive SPME technique in the wild. Scent emissions are dominated by aromatic compounds. Nevertheless, the presence of the terpenoid (E)-4,8-dimethylnona-1,3,7-triène (DMNT) is diagnostic of var. purpurea, with the volatile organic compounds (VOC) produced by some individuals containing up to 60% of DMNT. We evidence specific colour-scent associations in C. sylvatica, with two distinct scent profiles in the three colour varieties: the lilacina-like profile containing no or very little DMNT (<2%) and the purpurea-like profile containing DMNT (>2%). Calanthe sylvatica var. alba individuals group with one or the other scent profile independently of their population of origin. We suggest that white-flowered individuals have evolved at least twice, once from var. lilacina and at least once from var. purpurea after the colonisation of la Réunion. White-flowered individuals may have been favoured by the particular pollinator fauna characterising the island. These flowering varieties of C. sylvatica, which display three colours but two scents profiles prove that colour is not always a good indicator of odour and that colour-scent associations may be complex, depending on pollination ecology of the populations concerned.
Collapse
Affiliation(s)
- Roxane Delle-Vedove
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR CNRS 5175, Montpellier, France.
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Schatz B, Geoffroy A, Dainat B, Bessière JM, Buatois B, Hossaert-McKey M, Selosse MA. A case study of modified interactions with symbionts in a hybrid mediterranean orchid. AMERICAN JOURNAL OF BOTANY 2010; 97:1278-88. [PMID: 21616880 DOI: 10.3732/ajb.0900303] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
PREMISE OF THE STUDY Most studies on orchid hybrids examine separately the effects of hybridization on interactions with pollinators or with mycorrhizal fungi. Here, we simultaneously investigated both interactions in the mediterranean food-deceptive Orchis simia, O. anthropophora, and their hybrid (O. ×bergonii) and tested a possible breakdown of coevolution using a multidisciplinary approach. • METHODS We compared leaf growth, seed viability, emitted scent, and mycorrhizal fungi (species and rate of infection) among these three taxa. • KEY RESULTS We show that leaf surface is greater in adult hybrids than in the parental species, suggesting a heterosis effect for vegetative growth. We demonstrate that flowers of the two parental species emit well-differentiated bouquets of volatile organic compounds, while hybrids emit larger quantities, accumulating most compounds of the two parental species. However, hybrids fail to attract pollinators and have a 10 times lower fruit set. We determined that closely related Tulasnellales are mycorrhizal in the three taxa, suggesting that the mycorrhizal partner does not impair hybrid survival. We propose an interpretative model for O. ×bergonii compared with its parents. • CONCLUSIONS In hybrids, carbon resources normally devoted to reproduction may be reallocated to the mycorrhizal symbiosis as a result of the disruption of the pollination interaction in hybrids. Higher mycorrhizal infection may in turn enhance vegetative growth and scent emission. Such interplay between the two obligate biotic interactions yields new insights into hybridization among orchids.
Collapse
Affiliation(s)
- Bertrand Schatz
- Equipe Interactions Biotiques, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR CNRS 5175, 1919 route de Mende, F-34293 Montpellier Cedex 5, France
| | | | | | | | | | | | | |
Collapse
|
38
|
|
39
|
Vereecken NJ, McNeil JN. Cheaters and liars: chemical mimicry at its finestThe present review is one in the special series of reviews on animal-plant interactions.In memory of Jan Tengö (1939–2010), who made exceptional contributions to our understanding of the chemical ecology of solitary bees, including chemical mimicry. CAN J ZOOL 2010. [DOI: 10.1139/z10-040] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chemical mimicry is an essential part of certain interspecific interactions, where the outcome for both species may depend on the degree to which the original signals are mimicked. In this review, we discuss a number of specific cases relating to pollination and obtaining nutrient resources that we believe exemplify recent advances in our understanding of chemical mimicry. Subsequently, we suggest avenues for future ecological and chemical research that should allow us to gain further insight into the evolution of chemical mimicry.
Collapse
Affiliation(s)
- N. J. Vereecken
- Evolutionary Biology and Ecology, Free University of Brussels/Université Libre de Bruxelles, avenue FD Roosevelt 50 CP 160/12, B-1050 Brussels, Belgium
- Department of Biology, The University of Western Ontario, London ON N6A 5B7, Canada
- Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - J. N. McNeil
- Evolutionary Biology and Ecology, Free University of Brussels/Université Libre de Bruxelles, avenue FD Roosevelt 50 CP 160/12, B-1050 Brussels, Belgium
- Department of Biology, The University of Western Ontario, London ON N6A 5B7, Canada
- Institute of Systematic Botany, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| |
Collapse
|
40
|
Dormont L, Delle-Vedove R, Bessière JM, Hossaert-Mc Key M, Schatz B. Rare white-flowered morphs increase the reproductive success of common purple morphs in a food-deceptive orchid. THE NEW PHYTOLOGIST 2010; 185:300-310. [PMID: 19825015 DOI: 10.1111/j.1469-8137.2009.03052.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
How floral colour polymorphism can be maintained in evolutionary time is still debated. In rewardless orchids, it is unknown whether rare white-flowered morphs differ in scent chemistry from pigmented morphs, and whether such intraspecific variation in floral signals may have an impact on reproductive success. We compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of Orchis mascula, and recorded the fruit set of both colour morphs. We also used white ping-pong balls to mimic white-flowered morphs in field bioassays. We found that colour polymorphism was not associated with floral odour polymorphism. Surprisingly, when populations of purple-flowered plants included a few white-flowered individuals, the fruit set of the purple morph increased significantly (from 6 to 27%), while that of the white morph remained low. We obtained the same fourfold increase in fruit set when using ping-pong balls as visual lures, demonstrating the association between colour variation and fruit set, and the key role of visual signals in pollinator attraction. Our results are incompatible with negative frequency-dependent selection, a hypothesis invoked to explain colour polymorphism in other rewardless orchids. We propose several hypotheses to explain the maintenance of white morphs in O. mascula.
Collapse
Affiliation(s)
- L Dormont
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), CNRS, 1919 Route de Mende, 34293 Montpellier, France.
| | | | | | | | | |
Collapse
|
41
|
Wright GA, Schiestl FP. The evolution of floral scent: the influence of olfactory learning by insect pollinators on the honest signalling of floral rewards. Funct Ecol 2009. [DOI: 10.1111/j.1365-2435.2009.01627.x] [Citation(s) in RCA: 243] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
42
|
Majetic CJ, Raguso RA, Ashman TL. The sweet smell of success: floral scent affects pollinator attraction and seed fitness inHesperis matronalis. Funct Ecol 2009. [DOI: 10.1111/j.1365-2435.2008.01517.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
43
|
Vandewoestijne S, Róis AS, Caperta A, Baguette M, Tyteca D. Effects of individual and population parameters on reproductive success in three sexually deceptive orchid species. PLANT BIOLOGY (STUTTGART, GERMANY) 2009; 11:454-63. [PMID: 19470116 DOI: 10.1111/j.1438-8677.2008.00125.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Reproductive success (RS) in orchids in general, and in non-rewarding species specifically, is extremely low. RS is pollinator and pollination limited in food deceptive orchids, but this has rarely been studied in sexually deceptive orchid species. Here, we tested the effects of several individual (plant height, inflorescence size, nearest neighbour distance and flower position) and population (patch geometry, population density and size) parameters on RS in three sexually deceptive Ophrys (Orchidaceae) species. Inter-specific differences were observed in RS of flowers situated in the upper versus the lower part of the inflorescence, likely due to species-specific pollinator behaviour. For all three species examined, RS increased with increasing plant height, inflorescence size and nearest neighbour distance. RS generally increased with decreasing population density and increasing patch elongation. Given these results, we postulate that pollinator availability, rather than pollinator learning, is the most limiting factor in successful reproduction for sexually deceptive orchids. Our results also suggest that olfactory 'display' (i.e. versus optical display), in terms of inflorescence size (and co-varying plant height), plays a key role in individual RS of sexually deceptive orchids. In this regard, several hypotheses are suggested and discussed.
Collapse
Affiliation(s)
- S Vandewoestijne
- Biodiversity Research Centre, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | | | | | | | | |
Collapse
|