1
|
Magalhães DM, Lourenção AL, Bento JMS. Beneath the blooms: Unearthing the effect of rhizospheric bacteria on floral signals and pollinator preferences. PLANT, CELL & ENVIRONMENT 2024; 47:782-798. [PMID: 37994626 DOI: 10.1111/pce.14771] [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: 05/31/2023] [Revised: 08/29/2023] [Accepted: 11/09/2023] [Indexed: 11/24/2023]
Abstract
The relationship between plants and pollinators is known to be influenced by ecological interactions with other community members. While most research has focused on aboveground communities affecting plant-pollinator interactions, it is increasingly recognized that soil-dwelling organisms can directly or indirectly impact these interactions. Although studies have examined the effects of arbuscular mycorrhizal fungi on floral traits, there is a gap in research regarding similar effects associated with plant growth-promoting rhizobacteria (PGPR), particularly concerning floral scent. Our study aimed to investigate the influence of the PGPR Bacillus amyloliquefaciens on the floral traits of wild (Solanum habrochaites, Solanum pimpinellifolium and Solanum peruvianum) and cultivated tomato (Solanum lycopersicum), as well as the impact of microbially-driven changes in floral scent on the foraging behaviour of the stingless bee Melipona quadrifasciata. Our findings revealed that inoculating tomatoes with PGPR led to an increased number of flowers and enhanced overall floral volatile emission. Additionally, we observed higher flower biomass and pollen levels in all species, except S. peruvianum. Importantly, these changes in volatile emissions influenced the foraging behaviour of M. quadrifasciata significantly. Our results highlight the impact of beneficial soil microbes on plant-pollinator interactions, shedding light on the multiple effects that plant-microbial interactions can have on aboveground organisms.
Collapse
Affiliation(s)
- Diego M Magalhães
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, São Paulo, Brazil
| | - André L Lourenção
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, São Paulo, Brazil
| | - José Maurício S Bento
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, São Paulo, Brazil
| |
Collapse
|
2
|
Dötterl S, Gershenzon J. Chemistry, biosynthesis and biology of floral volatiles: roles in pollination and other functions. Nat Prod Rep 2023; 40:1901-1937. [PMID: 37661854 DOI: 10.1039/d3np00024a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Covering: 2010 to 2023Floral volatiles are a chemically diverse group of plant metabolites that serve multiple functions. Their composition is shaped by environmental, ecological and evolutionary factors. This review will summarize recent advances in floral scent research from chemical, molecular and ecological perspectives. It will focus on the major chemical classes of floral volatiles, on notable new structures, and on recent discoveries regarding the biosynthesis and the regulation of volatile emission. Special attention will be devoted to the various functions of floral volatiles, not only as attractants for different types of pollinators, but also as defenses of flowers against enemies. We will also summarize recent findings on how floral volatiles are affected by abiotic stressors, such as increased temperatures and drought, and by other organisms, such as herbivores and flower-dwelling microbes. Finally, this review will indicate current research gaps, such as the very limited knowledge of the isomeric pattern of chiral compounds and its importance in interspecific interactions.
Collapse
Affiliation(s)
- Stefan Dötterl
- Department of Environment & Biodiversity, Paris Lodron University Salzburg, Hellbrunnerstr 34, 5020 Salzburg, Austria.
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany.
| |
Collapse
|
3
|
Thomas G, Rusman Q, Morrison WR, Magalhães DM, Dowell JA, Ngumbi E, Osei-Owusu J, Kansman J, Gaffke A, Pagadala Damodaram KJ, Kim SJ, Tabanca N. Deciphering Plant-Insect-Microorganism Signals for Sustainable Crop Production. Biomolecules 2023; 13:997. [PMID: 37371577 PMCID: PMC10295935 DOI: 10.3390/biom13060997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Agricultural crop productivity relies on the application of chemical pesticides to reduce pest and pathogen damage. However, chemical pesticides also pose a range of ecological, environmental and economic penalties. This includes the development of pesticide resistance by insect pests and pathogens, rendering pesticides less effective. Alternative sustainable crop protection tools should therefore be considered. Semiochemicals are signalling molecules produced by organisms, including plants, microbes, and animals, which cause behavioural or developmental changes in receiving organisms. Manipulating semiochemicals could provide a more sustainable approach to the management of insect pests and pathogens across crops. Here, we review the role of semiochemicals in the interaction between plants, insects and microbes, including examples of how they have been applied to agricultural systems. We highlight future research priorities to be considered for semiochemicals to be credible alternatives to the application of chemical pesticides.
Collapse
Affiliation(s)
- Gareth Thomas
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Quint Rusman
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008 Zürich, Switzerland;
| | - William R. Morrison
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Grain and Animal Health Research, 1515 College Ave., Manhattan, KS 66502, USA;
| | - Diego M. Magalhães
- Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil;
| | - Jordan A. Dowell
- Department of Plant Sciences, University of California, Davis, One Shields Ave., Davis, CA 95616, USA;
| | - Esther Ngumbi
- Department of Entomology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA;
| | - Jonathan Osei-Owusu
- Department of Biological, Physical and Mathematical Sciences, University of Environment and Sustainable Development, Somanya EY0329-2478, Ghana;
| | - Jessica Kansman
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Alexander Gaffke
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Medical, Agricultural, and Veterinary Entomology, 6383 Mahan Dr., Tallahassee, FL 32308, USA;
| | | | - Seong Jong Kim
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Natural Products Utilization Research Unit, University, MS 38677, USA;
| | - Nurhayat Tabanca
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Subtropical Horticulture Research Station, 13601 Old Cutler Rd., Miami, FL 33158, USA
| |
Collapse
|
4
|
Gomez Ramirez WC, Thomas NK, Muktar IJ, Riabinina O. The neuroecology of olfaction in bees. CURRENT OPINION IN INSECT SCIENCE 2023; 56:101018. [PMID: 36842606 DOI: 10.1016/j.cois.2023.101018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/30/2022] [Accepted: 02/20/2023] [Indexed: 05/03/2023]
Abstract
The focus of bee neuroscience has for a long time been on only a handful of social honeybee and bumblebee species, out of thousands of bees species that have been described. On the other hand, information about the chemical ecology of bees is much more abundant. Here we attempted to compile the scarce information about olfactory systems of bees across species. We also review the major categories of intra- and inter-specific olfactory behaviors of bees, with specific focus on recent literature. We finish by discussing the most promising avenues for bee olfactory research in the near future.
Collapse
|
5
|
Cordeiro GD, Dötterl S. Floral Scents in Bee-Pollinated Buckwheat and Oilseed Rape under a Global Warming Scenario. INSECTS 2023; 14:242. [PMID: 36975927 PMCID: PMC10057843 DOI: 10.3390/insects14030242] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Many wild plants and crops are pollinated by insects, which often use floral scents to locate their host plants. The production and emission of floral scents are temperature-dependent; however, little is known about how global warming affects scent emissions and the attraction of pollinators. We used a combination of chemical analytical and electrophysiological approaches to quantify the influence of a global warming scenario (+5 °C in this century) on the floral scent emissions of two important crop species, i.e., buckwheat (Fagopyrum esculentum) and oilseed rape (Brassica napus), and to test whether compounds that are potentially different between the treatments can be detected by their bee pollinators (Apis mellifera and Bombus terrestris). We found that only buckwheat was affected by increased temperatures. Independent of temperature, the scent of oilseed rape was dominated by p-anisaldehyde and linalool, with no differences in relative scent composition and the total amount of scent. Buckwheat emitted 2.4 ng of scent per flower and hour at optimal temperatures, dominated by 2- and 3-methylbutanoic acid (46%) and linalool (10%), and at warmer temperatures threefold less scent (0.7 ng/flower/hour), with increased contributions of 2- and 3-methylbutanoic acid (73%) to the total scent and linalool and other compounds being absent. The antennae of the pollinators responded to various buckwheat floral scent compounds, among them compounds that disappeared at increased temperatures or were affected in their (relative) amounts. Our results highlight that increased temperatures differentially affect floral scent emissions of crop plants and that, in buckwheat, the temperature-induced changes in floral scent emissions affect the olfactory perception of the flowers by bees. Future studies should test whether these differences in olfactory perception translate into different attractiveness of buckwheat flowers to bees.
Collapse
|
6
|
Gfrerer E, Laina D, Wagner R, Gibernau M, Hörger AC, Comes HP, Dötterl S. Antennae of psychodid and sphaerocerid flies respond to a high variety of floral scent compounds of deceptive Arum maculatum L. Sci Rep 2022; 12:5086. [PMID: 35332183 PMCID: PMC8948215 DOI: 10.1038/s41598-022-08196-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/04/2022] [Indexed: 11/25/2022] Open
Abstract
Insect-pollinated plants often release complex mixtures of floral scents to attract their pollinators. Yet scent compounds eliciting physiological or behavioural responses in pollinators have only been identified in few plant species. The sapromyiophilous aroid Arum maculatum releases a highly diverse dung-like scent with overall more than 300 different compounds recorded so far to attract its psychodid and other fly pollinators. The volatiles' role in pollinator attraction is mostly unknown. To identify potential behaviourally active compounds, we recorded electroantennographic responses of four Psychodidae and one Sphaeroceridae species to (1) inflorescence scents of A. maculatum and (2) the scents released by cow dung, likely imitated by the plant species. Here we show that these flies are sensitive to 78 floral volatiles of various chemical classes, 18 of which were also found in cow dung. Our study, which for the first time determined physiologically active compounds in the antennae of Psychoda spp. and Sphaeroceridae, identified various volatiles not known to be biologically active in any floral visitors so far. The obtained results help deciphering the chemical basis that enables A. maculatum and other plants, pollinated by psychodids and sphaerocerids, to attract and deceive their pollinators.
Collapse
Affiliation(s)
- Eva Gfrerer
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Danae Laina
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Rüdiger Wagner
- Department of Limnology, University of Kassel, 34127, Kassel, Germany
| | - Marc Gibernau
- Laboratory of Sciences for the Environment, CNRS - University of Corsica, 20000, Ajaccio, France
| | - Anja C Hörger
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Hans Peter Comes
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, 5020, Salzburg, Austria
| | - Stefan Dötterl
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, 5020, Salzburg, Austria.
| |
Collapse
|
7
|
Leoni V, Giupponi L, Pavlovic R, Gianoncelli C, Cecati F, Ranzato E, Martinotti S, Pedrali D, Giorgi A, Panseri S. Multidisciplinary analysis of Italian Alpine wildflower honey reveals criticalities, diversity and value. Sci Rep 2021; 11:19316. [PMID: 34588574 PMCID: PMC8481395 DOI: 10.1038/s41598-021-98876-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/30/2021] [Indexed: 11/21/2022] Open
Abstract
Wildflower honeys produced in mountain grasslands are an expression of the biodiversity of these fragile habitats. Despite its importance, the botanical origin of honey is often defined without performing formal analysis. The aim of the study was to characterize six wildflower mountain honeys produced in the Italian Alps with different analytic techniques (SPME-GC-MS, HPLC-Orbitrap, cicatrizing and antioxidant activity) alongside melissopalynological analysis and botanical definition of the production area. Even though the apiaries were in mountain grasslands rich in Alpine herbaceous species, the honey could be defined as rhododendron/raspberry unifloral or raspberry and rhododendron bifloral while the honey produced at the lowest altitude differed due to the presence of linden, heather and chestnut. The non-compliance of the honey could be due to habitat (meadows and pastures) fragmentation, but also to specific compounds involved in the plant-insect relationship, such as kynurenic acid, present in a high quantity in the sample rich in chestnut pollen. 255 volatile compounds were detected as well as some well-known markers of specific botanic essences, in particular chestnut, linden and heather, also responsible for most of the differences in aroma profiling. A high correlation between nicotinaldehyde content and percentage of raspberry pollen (r = 0.853, p < 0.05) was found. Phenolic acid and hydroxy-fatty acid were predominant in the chestnut pollen dominant honey, which presented the highest antioxidant activity and the lowest cicatrizing activity, while the flavonoid fraction was accentuated in one sample (rhododendron pollen prevalent), that was also the one with the highest effect on wound closure, although all samples had similar cicatrizing effects apart from the chestnut pollen dominant honey (lowest cicatrizing activity). Our study highlighted the difficulty of producing mountain wildflower honey and the importance of a thorough characterization of this product, also to encourage its production and valorisation.
Collapse
Affiliation(s)
- Valeria Leoni
- Centre of Applied Studies for the Sustainable Management and Protection of Mountain Areas (CRC Ge.S.Di.Mont.), University of Milan, Via Morino 8, 25048, Edolo, BS, Italy
| | - Luca Giupponi
- Centre of Applied Studies for the Sustainable Management and Protection of Mountain Areas (CRC Ge.S.Di.Mont.), University of Milan, Via Morino 8, 25048, Edolo, BS, Italy
| | - Radmila Pavlovic
- Department of Health, Animal Science and Food Safety (VESPA), University of Milan, Via Celoria 10, 20133, Milan, Italy.
| | - Carla Gianoncelli
- Fondazione Fojanini Di Studi Superiori, Via Valeriana 32, 23100, Sondrio, Italy
| | - Francisco Cecati
- Instituto de Investigaciones en Tecnología Química (INTEQUI), Universidad Nacional de San Luis, Almirante Brown 1455, 5700, San Luis, Argentina
| | - Elia Ranzato
- DiSIT-Dipartimento Di Scienze E Innovazione Tecnologica, University of Piemonte Orientale, piazza Sant'Eusebio 5, 13100, Vercelli, Italy
| | - Simona Martinotti
- DiSIT-Dipartimento Di Scienze E Innovazione Tecnologica, University of Piemonte Orientale, piazza Sant'Eusebio 5, 13100, Vercelli, Italy
| | - Davide Pedrali
- Centre of Applied Studies for the Sustainable Management and Protection of Mountain Areas (CRC Ge.S.Di.Mont.), University of Milan, Via Morino 8, 25048, Edolo, BS, Italy
| | - Annamaria Giorgi
- Centre of Applied Studies for the Sustainable Management and Protection of Mountain Areas (CRC Ge.S.Di.Mont.), University of Milan, Via Morino 8, 25048, Edolo, BS, Italy
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy (DISAA), University of Milan, Via Celoria 2, 20133, Milan, Italy
| | - Sara Panseri
- Department of Health, Animal Science and Food Safety (VESPA), University of Milan, Via Celoria 10, 20133, Milan, Italy
| |
Collapse
|
8
|
Gfrerer E, Laina D, Gibernau M, Fuchs R, Happ M, Tolasch T, Trutschnig W, Hörger AC, Comes HP, Dötterl S. Floral Scents of a Deceptive Plant Are Hyperdiverse and Under Population-Specific Phenotypic Selection. FRONTIERS IN PLANT SCIENCE 2021; 12:719092. [PMID: 34630465 PMCID: PMC8500232 DOI: 10.3389/fpls.2021.719092] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Floral scent is a key mediator in plant-pollinator interactions. However, little is known to what extent intraspecific scent variation is shaped by phenotypic selection, with no information yet in deceptive plants. In this study, we collected inflorescence scent and fruit set of the deceptive moth fly-pollinated Arum maculatum L. (Araceae) from six populations north vs. five populations south of the Alps, accumulating to 233 samples in total, and tested for differences in scent, fruit set, and phenotypic selection on scent across this geographic barrier. We recorded 289 scent compounds, the highest number so far reported in a single plant species. Most of the compounds occurred both north and south of the Alps; however, plants of the different regions emitted different absolute and relative amounts of scent. Fruit set was higher north than south of the Alps, and some, but not all differences in scent could be explained by differential phenotypic selection in northern vs. southern populations. This study is the first to provide evidence that floral scents of a deceptive plant are under phenotypic selection and that phenotypic selection is involved in shaping geographic patterns of floral scent in such plants. The hyperdiverse scent of A. maculatum might result from the imitation of various brood substrates of its pollinators.
Collapse
Affiliation(s)
- Eva Gfrerer
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Danae Laina
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Marc Gibernau
- Laboratory of Sciences for the Environment, CNRS – University of Corsica, Ajaccio, France
| | - Roman Fuchs
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Martin Happ
- Lab for Intelligent Data Analytics Salzburg, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Till Tolasch
- FG Tierökologie, University of Hohenheim, Stuttgart, Germany
| | - Wolfgang Trutschnig
- Department of Mathematics, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Anja C. Hörger
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Hans Peter Comes
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Stefan Dötterl
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| |
Collapse
|
9
|
Moré M, Soteras F, Ibañez AC, Dötterl S, Cocucci AA, Raguso RA. Floral Scent Evolution in the Genus Jaborosa (Solanaceae): Influence of Ecological and Environmental Factors. PLANTS (BASEL, SWITZERLAND) 2021; 10:1512. [PMID: 34451557 PMCID: PMC8398055 DOI: 10.3390/plants10081512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/05/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Floral scent is a key communication channel between plants and pollinators. However, the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a 'warm Lowland Subtropical nectar-rewarding clade' with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a 'cool-temperate brood-deceptive clade' of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across "pollinator climates" (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.
Collapse
Affiliation(s)
- Marcela Moré
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Florencia Soteras
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Ana C. Ibañez
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Stefan Dötterl
- Department of Biosciences, Paris-Lodron-University of Salzburg, 5020 Salzburg, Austria;
| | - Andrea A. Cocucci
- Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba CP 5000, Argentina; (F.S.); (A.C.I.); (A.A.C.)
| | - Robert A. Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
10
|
Burger H, Marquardt M, Babucke K, Heuel KC, Ayasse M, Dötterl S, Galizia CG. Neural and behavioural responses of the pollen-specialist bee Andrena vaga to Salix odours. J Exp Biol 2021; 224:269108. [PMID: 34113983 DOI: 10.1242/jeb.242166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 06/02/2021] [Indexed: 01/05/2023]
Abstract
An effective means of finding food is crucial for organisms. Whereas specialized animals select a small number of potentially available food sources, generalists use a broader range. Specialist (oligolectic) bees forage on a small range of flowering plants for pollen and use primarily olfactory and visual cues to locate their host flowers. So far, however, little is known about the specific cues oligoleges use to discriminate between hosts and non-hosts and how floral scent compounds of hosts and non-hosts are processed in the bees' olfactory system. In this study, we recorded physiological responses of the antennae (electroantennographic detection coupled to gas chromatography; GC-EAD) and in the brain (optical imaging; GC imaging), and studied host-finding behaviour of oligolectic Andrena vaga bees, a specialist on Salix plants. In total, we detected 37 physiologically active compounds in host and non-host scents. 4-Oxoisophorone, a common constituent in the scent of many Salix species, evoked strong responses in the antennal lobe glomeruli of A. vaga, but not the generalist honeybee Apis mellifera. The specific glomerular responses to 4-oxoisophorone in natural Salix scents reveals a high degree of specialization in A. vaga for this typical Salix odorant component. In behavioural experiments, we found olfactory cues to be the key attractants for A. vaga to Salix hosts, which are also used to discriminate between hosts and non-hosts, and A. vaga demonstrated a behavioural activity for 4-oxoisophorone. A high sensitivity to floral scents enables the specialized bees to effectively find flowers and it appears that A. vaga bees are highly tuned to 4-oxoisophorone at a very low concentration.
Collapse
Affiliation(s)
- Hannah Burger
- Department of Neurobiology, University of Konstanz, 78457 Konstanz, Germany.,Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Melanie Marquardt
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Katharina Babucke
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Kim C Heuel
- Department of Neurobiology, University of Konstanz, 78457 Konstanz, Germany.,Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Stefan Dötterl
- Department of Biosciences, Paris-Lodron-University of Salzburg, 5020 Salzburg, Austria
| | - C Giovanni Galizia
- Department of Neurobiology, University of Konstanz, 78457 Konstanz, Germany
| |
Collapse
|
11
|
Comparative Analysis of Volatile Compounds in Flowers of Different Actinidia Species. PLANTS 2020; 9:plants9121675. [PMID: 33266005 PMCID: PMC7760476 DOI: 10.3390/plants9121675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 11/16/2022]
Abstract
Among the actinidia genus (Actinidia spp.) native to China, few species are grown commercially for their edible and healthy fruits. As they are dioecious plants, a lot of interest is paid to effective pollination and to insects as the most efficient pollinators. In this study we have concentrated on the composition of volatile compounds in male flowers of four different actinidia species (A. chinensis var. deliciosa, A. arguta, A. kolomikta and A. polygama) and on the diversity between male and female flower volatiles for the two most winter-hardy species (A. arguta and A. kolomikta) with growing commercial value. Analyses were provided using gas chromatography with mass spectrometry (GC-MS). In total, 120 compounds were found in 15 actinidia genotypes. However, the number of identified compounds varied between species. Different main compounds or groups of volatile compounds characterised flowers of every species. Smaller differences were observed between male and female flowers of the same species. Our results suggest that actinidia flowers could be attractive to pollinating insects.
Collapse
|
12
|
Lukas K, Dötterl S, Ayasse M, Burger H. Olfactory and Visual Floral Signals of Hedera helix and Heracleum sphondylium Involved in Host Finding by Nectar-Foraging Social Wasps. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.571454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
13
|
Polidori C, Jorge A, Ornosa C. Antennal morphology and sensillar equipment vary with pollen diet specialization in Andrena bees. ARTHROPOD STRUCTURE & DEVELOPMENT 2020; 57:100950. [PMID: 32413703 DOI: 10.1016/j.asd.2020.100950] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/19/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
Several studies recently reported that specialized (oligolectic) bees, which collect pollen from few host plants, use, besides visual cues, specific volatiles to find their hosts. Generalist (polylectic) bees, on the other hand, likely have to recognize a wider range of volatiles because they forage on many plant species. Bee antennal sensory equipment may thus be under selection to optimize plant host recognition. This selection may have led to variation in sensory equipment morphology with diet specialization (lecty). We tested if lecty correlates with antennal morphology and abundance of the main olfactory/gustatory sensilla (sensilla trichoidea (ST), placoidea (SP), sensilla basiconica (SB)) in the genus Andrena (Hymenoptera: Andrenidae). Across 24 species, and after having controlled for body size, we found polylectic species to have a longer and narrower flagellomer F9 (the one with highest abundance of sensilla), and to have a greater ST density on F9, compared with oligolectic species. Neither SP density nor SB number varied with lecty. A cluster analysis furthermore depicted groups of species that reasonably reflect diet specialization. Our results are in line with the previously observed lower number of glomeruli in the brain of oligolectic, compared with polylectic, bees. A formal correction for phylogeny is necessary to confirm our preliminary conclusion that pollen diet specialization has driven the morphology of the peripheral sensory system in this bee genus.
Collapse
Affiliation(s)
- Carlo Polidori
- Instituto de Ciencias Ambientales (ICAM), Universidad de Castilla-La Mancha, Avenida Carlos III, s/n, E-45071, Toledo, Spain.
| | - Alberto Jorge
- Laboratorio de Sistemática Molecular, Museo Nacional de Ciencias Naturales (CSIC), C/ José Gutiérrez Abascal 2, E-28006, Madrid, Spain.
| | - Concepción Ornosa
- Departamento de Biodiversidad, Ecología y Evolución, Universidad Complutense de Madrid, C/ José Antonio Nováis, 12, E-28040, Madrid, Spain.
| |
Collapse
|