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Russell AL, Buchmann SL, Ascher JS, Wang Z, Kriebel R, Jolles DD, Orr MC, Hughes AC. Global patterns and drivers of buzzing bees and poricidal plants. Curr Biol 2024; 34:3055-3063.e5. [PMID: 38925116 DOI: 10.1016/j.cub.2024.05.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/06/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
Foraging behavior frequently plays a major role in driving the geographic distribution of animals. Buzzing to extract protein-rich pollen from flowers is a key foraging behavior used by bee species across at least 83 genera (these genera comprise ∼58% of all bee species). Although buzzing is widely recognized to affect the ecology and evolution of bees and flowering plants (e.g., buzz-pollinated flowers), global patterns and drivers of buzzing bee biogeography remain unexplored. Here, we investigate the global species distribution patterns within each bee family and how patterns and drivers differ with respect to buzzing bee species. We found that both distributional patterns and drivers of richness typically differed for buzzing species compared with hotspots for all bee species and when grouped by family. A major predictor of the distribution, but not species richness overall for buzzing members of four of the five major bee families included in analyses (Andrenidae, Halictidae, Colletidae, and to a lesser extent, Apidae), was the richness of poricidal flowering plant species, which depend on buzzing bees for pollination. Because poricidal plant richness was highest in areas with low wind and high aridity, we discuss how global hotspots of buzzing bee biodiversity are likely influenced by both biogeographic factors and plant host availability. Although we explored global patterns with state-level data, higher-resolution work is needed to explore local-level drivers of patterns. From a global perspective, buzz-pollinated plants clearly play a greater role in the ecology and evolution of buzzing bees than previously predicted.
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Affiliation(s)
- Avery L Russell
- Department of Biology, Missouri State University, Springfield, MO 65897, USA.
| | - Stephen L Buchmann
- Department of Ecology and Evolutionary Biology and Department of Entomology, University of Arizona, Tucson, AZ, USA
| | - John S Ascher
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Zhiheng Wang
- College of Urban & Environmental Sciences, Peking University, 5 Yiheyuan Road, Beijing, China
| | - Ricardo Kriebel
- Department of Botany, Institute of Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, CA, USA
| | - Diana D Jolles
- Department of Biological Sciences, Plymouth State University, Plymouth, NH, USA
| | - Michael C Orr
- Entomologie, Staatliches Museum für Naturkunde Stuttgart, Stuttgart, Germany; Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Alice C Hughes
- School of Biological Sciences, University of Hong Kong, Hong Kong, China.
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2
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Hemingway CT, Leonard AS, MacNeill FT, Pimplikar S, Muth F. Pollinator cognition and the function of complex rewards. Trends Ecol Evol 2024:S0169-5347(24)00146-0. [PMID: 39019730 DOI: 10.1016/j.tree.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 06/10/2024] [Accepted: 06/14/2024] [Indexed: 07/19/2024]
Abstract
The cognitive ecology of pollination is most often studied using simple rewards, yet flowers often contain multiple types of chemically complex rewards, each varying along multiple dimensions of quality. In this review we highlight ways in which reward complexity can impact pollinator cognition, demonstrating the need to consider ecologically realistic rewards to fully understand plant-pollinator interactions. We show that pollinators' reward preferences can be modulated by reward chemistry and the collection of multiple reward types. We also discuss how reward complexity can mediate pollinator learning through a variety of mechanisms, both with and without reward preference being altered. Finally, we show how an understanding of decision-making strategies is necessary to predict how pollinators' evaluation of reward options depends on the other options available.
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Affiliation(s)
- Claire T Hemingway
- Department of Ecology & Evolutionary Biology, Dabney Hall, 1416 Circle Dr., University of Tennessee, Knoxville, TN 37996, USA; Department of Psychology, Austin Peay, 1404 Circle Dr., University of Tennessee, Knoxville, TN 37996, USA; Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA.
| | - Anne S Leonard
- Department of Biology, 1664 North Virginia St, Mailstop 314, University of Nevada, Reno, NV 89557, USA
| | - Fiona Tiley MacNeill
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA
| | - Smruti Pimplikar
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA
| | - Felicity Muth
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA; Department of Neurobiology, Physiology, and Behavior, 196 Briggs Hall, University of California, Davis, CA 95616, USA
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3
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Kostić AŽ, Dramićanin AM, Milinčić DD, Pešić MB. Exploring the Botanical Origins of Bee-Collected Pollen: A Comprehensive Historical and Contemporary Analysis. Chem Biodivers 2024; 21:e202400194. [PMID: 38717321 DOI: 10.1002/cbdv.202400194] [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: 01/22/2024] [Accepted: 05/08/2024] [Indexed: 06/12/2024]
Abstract
Bee-collected pollen is one of the most important bee products. In order to predict its chemical composition and nutritional value botanical origin of pollen plays a crucial role. This review intended to collect all available data published about botanical origin of pollen collected all around the world. Due to enourmous amount of data and variables nonlinear principal component analysis (NLPCA), by applying Categorical Principal Component Analysis (CATPCA), was conducted in order to try to determine any specifity and/or differences among samples. Also, importance of some plant families/genera/species for bees was monitored. Based on CATPCA results families can serve in order to distinct samples from North/South America. Also, some samples from Europe (Turkey and Serbia) were characterized with presence of some specific families. Genera were excellent tool to distinguish samples from different parts of Brazil as well as Australia, Asia and Africa. Due to high and specific biodiversity pollen samples obtained from Sonoran desert (USA) completely were separated during analysis. This review presents the first attempt to summarize and classify a large number of data about botanical sources of bee-collected pollen.
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Affiliation(s)
- Aleksandar Ž Kostić
- Chair of Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080, Belgrade, Serbia
| | - Aleksandra M Dramićanin
- Chair of Analytical Chemistry, Faculty of Chemistry, University of Belgrade, Studentski Trg 12-16, 11000, Belgrade, Serbia
| | - Danijel D Milinčić
- Chair of Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080, Belgrade, Serbia
| | - Mirjana B Pešić
- Chair of Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080, Belgrade, Serbia
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4
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Fernandes KE, Frost EA, Kratz M, Carter DA. Pollen products collected from honey bee hives experiencing minor stress have altered fungal communities and reduced antimicrobial properties. FEMS Microbiol Ecol 2024; 100:fiae091. [PMID: 38886123 PMCID: PMC11210501 DOI: 10.1093/femsec/fiae091] [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: 04/17/2024] [Revised: 06/06/2024] [Accepted: 06/14/2024] [Indexed: 06/20/2024] Open
Abstract
Fungi are increasingly recognized to play diverse roles within honey bee hives, acting as pathogens, mutualists, and commensals. Pollen products, essential for hive nutrition, host significant fungal communities with potential protective and nutritional benefits. In this study, we profile the fungal communities and antifungal properties of three pollen products from healthy and stressed hives: fresh pollen collected by forager bees from local plants; stored pollen packed into the comb inside the hive; and bee bread, which is stored pollen following anaerobic fermentation used for bee and larval nutrition. Using amplicon sequencing, we found significant differences in fungal community composition, with hive health and sample type accounting for 8.8% and 19.3% of variation in beta diversity, respectively. Pollen and bee bread extracts had species-specific antimicrobial activity and inhibited the fungal hive pathogens Ascosphaera apis, Aspergillus flavus, and Aspergillus fumigatus, and the bacterial hive pathogen Paenibacillus larvae. Activity was positively correlated with phenolic and antioxidant content and was diminished in stressed hives. The plant source of pollen determined by amplicon sequencing differed in stressed hives, suggesting altered foraging behaviour. These findings illustrate the complex interplay between honey bees, fungal communities, and hive products, which should be considered in hive management and conservation.
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Affiliation(s)
- Kenya E Fernandes
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
- Sydney Institute for Infectious Diseases, University of Sydney, Sydney, NSW 2006, Australia
| | - Elizabeth A Frost
- ABGU, A Joint Venture of NSW Department of Primary Industries and University of New England, Armidale, NSW 2350, Australia
- NSW Department of Primary Industries, Paterson, NSW 2421, Australia
| | - Madlen Kratz
- NSW Department of Primary Industries, Paterson, NSW 2421, Australia
| | - Dee A Carter
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
- Sydney Institute for Infectious Diseases, University of Sydney, Sydney, NSW 2006, Australia
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Bernauer OM, Jain A, de Bivort B, Holbrook NM, Myers SS, Ziska LH, Crall JD. Elevated atmospheric CO 2 has small, species-specific effects on pollen chemistry and plant growth across flowering plant species. Sci Rep 2024; 14:13760. [PMID: 38877021 PMCID: PMC11178917 DOI: 10.1038/s41598-024-63967-z] [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: 02/14/2024] [Accepted: 06/04/2024] [Indexed: 06/16/2024] Open
Abstract
Elevated atmospheric carbon dioxide (eCO2) can affect plant growth and physiology, which can, in turn, impact herbivorous insects, including by altering pollen or plant tissue nutrition. Previous research suggests that eCO2 can reduce pollen nutrition in some species, but it is unknown whether this effect is consistent across flowering plant species. We experimentally quantified the effects of eCO2 across multiple flowering plant species on plant growth in 9 species and pollen chemistry (%N an estimate for protein content and nutrition in 12 species; secondary chemistry in 5 species) in greenhouses. For pollen nutrition, only buckwheat significantly responded to eCO2, with %N increasing in eCO2; CO2 treatment did not affect pollen amino acid composition but altered secondary metabolites in buckwheat and sunflower. Plant growth under eCO2 exhibited two trends across species: plant height was taller in 44% of species and flower number was affected for 63% of species (3 species with fewer and 2 species with more flowers). The remaining growth metrics (leaf number, above-ground biomass, flower size, and flowering initiation) showed divergent, species-specific responses, if any. Our results indicate that future eCO2 is unlikely to uniformly change pollen chemistry or plant growth across flowering species but may have the potential to alter ecological interactions, or have particularly important effects on specialized pollinators.
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Affiliation(s)
- Olivia M Bernauer
- Department of Entomology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI, 53706, USA.
| | - Anupreksha Jain
- Department of Entomology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI, 53706, USA
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA
| | - Benjamin de Bivort
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA
| | - Samuel S Myers
- Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Baltimore, MD, 21205, USA
| | - Lewis H Ziska
- Mailman School of Public Health, Columbia University, 722 W. 168Th Street, New York, NY, 10032, USA
| | - James D Crall
- Department of Entomology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI, 53706, USA
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA
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6
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Moore CD, Farman DI, Särkinen T, Stevenson PC, Vallejo-Marín M. Floral scent changes in response to pollen removal are rare in buzz-pollinated Solanum. PLANTA 2024; 260:15. [PMID: 38829528 PMCID: PMC11147924 DOI: 10.1007/s00425-024-04403-4] [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: 11/26/2023] [Accepted: 03/30/2024] [Indexed: 06/05/2024]
Abstract
MAIN CONCLUSION One of seven Solanum taxa studied displayed associations between pollen presence and floral scent composition and volume, suggesting buzz-pollinated plants rarely use scent as an honest cue for foraging pollinators. Floral scent influences the recruitment, learning, and behaviour of floral visitors. Variation in floral scent can provide information on the amount of reward available or whether a flower has been visited recently and may be particularly important in species with visually concealed rewards. In many buzz-pollinated flowers, tubular anthers opening via small apical pores (poricidal anthers) visually conceal pollen and appear similar regardless of pollen quantity within the anther. We investigated whether pollen removal changes floral scent composition and emission rate in seven taxa of buzz-pollinated Solanum (Solanaceae). We found that pollen removal reduced both the overall emission of floral scent and the emission of specific compounds (linalool and farnesol) in S. lumholtzianum. Our findings suggest that in six out of seven buzz-pollinated taxa studied here, floral scent could not be used as a signal by visitors as it does not contain information on pollen availability.
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Affiliation(s)
- C Douglas Moore
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, UK.
| | - Dudley I Farman
- Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
| | - Tiina Särkinen
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, UK
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE, UK
| | - Mario Vallejo-Marín
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, UK
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, 752 36, Uppsala, Sweden
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7
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Zenchyzen B, Acorn JH, Merkosky K, Hall JC. Shining a light on UV-fluorescent floral nectar after 50 years. Sci Rep 2024; 14:11992. [PMID: 38796543 PMCID: PMC11128001 DOI: 10.1038/s41598-024-62626-7] [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: 02/28/2024] [Accepted: 05/20/2024] [Indexed: 05/28/2024] Open
Abstract
Nature is aglow with numerous captivating examples of UV-fluorescence in the animal kingdom. Despite a putative role as a visual signal, exploration of UV-fluorescence in plants and its role in plant-animal interactions is lagging in comparison. Almost 50 years ago, UV-fluorescence of floral nectar, a crucial reward for pollinators, was reported for 23 flowering plant species. Since this intriguing discovery, UV-fluorescent nectar has only seldom been addressed in the scientific literature and has not been scrutinized in a phylogenetic or ecological context. Here, we report the prevalence of vibrant UV-fluorescent floral nectar across the family Cleomaceae, including the first photographic documentation in vivo colour for flowering plants. Though Cleomaceae flowers are morphologically diverse varying in colour, nectary prominence, and nectar volume, UV-fluorescent floral nectar may be a ubiquitous characteristic of the family. Fluorescence spectra show that the identity and number of fluorescent compounds in floral nectar may differ among Cleomaceae species. As Cleomaceae pollinators range from insects to bats and birds, we suggest that the UV-fluorescent floral nectar not only functions as a visual cue for the diurnal pollinators but also for the nocturnal/crepuscular pollinators in low light settings.
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Affiliation(s)
- Brandi Zenchyzen
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
| | - John H Acorn
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Kian Merkosky
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Jocelyn C Hall
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
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8
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Rivest S, Lee ST, Cook D, Forrest JRK. Consequences of pollen defense compounds for pollinators and antagonists in a pollen-rewarding plant. Ecology 2024; 105:e4306. [PMID: 38590050 DOI: 10.1002/ecy.4306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/09/2024] [Accepted: 02/19/2024] [Indexed: 04/10/2024]
Abstract
Plants produce an array of defensive compounds with toxic or deterrent effects on insect herbivores. Pollen can contain relatively high concentrations of such defense compounds, but the causes and consequences of this enigmatic phenomenon remain mostly unknown. These compounds could potentially protect pollen against antagonists but could also reduce flower attractiveness to pollinators. We combined field observations of the pollen-rewarding Lupinus argenteus with chemical analysis and laboratory assays to test three hypotheses for the presence of pollen defense compounds: (1) these compounds are the result of spillover from adjacent tissues, (2) they protect against pollen thieves, and (3) they act as antimicrobial compounds. We also tested whether pollen defense compounds affect pollinator behavior. We found a positive relationship between alkaloid concentrations in pollen and petals, supporting the idea that pollen defense compounds partly originate from spillover. However, pollen and petals exhibited quantitatively (but not qualitatively) distinct alkaloid profiles, suggesting that plants can adjust pollen alkaloid composition independently from that of adjacent tissues. We found no relationship between pollen alkaloid concentration and the abundance of pollen thieves in Lupinus flowers. However, pollen alkaloids were negatively associated with bacterial abundance. Finally, plants with more alkaloids in their pollen received more pollinator visits, but these visits were shorter, resulting in no change in the overall number of flowers visited. We propose that pollen defense compounds are partly the result of spillover from other tissues, while they also play an antimicrobial role. The absence of negative effects of these compounds on pollinator visitation likely allows their maintenance in pollen at relatively high concentrations. Taken together, our results suggest that pollen alkaloids affect and are mediated by the interplay of multiple interactions.
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Affiliation(s)
- Sébastien Rivest
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA
| | - Stephen T Lee
- USDA ARS Poisonous Plant Research Laboratory, Logan, Utah, USA
| | - Daniel Cook
- USDA ARS Poisonous Plant Research Laboratory, Logan, Utah, USA
| | - Jessica R K Forrest
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA
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Zhou Z, Zhang H, Mashilingi SK, Jie C, Guo B, Guo Y, Hu X, Iqbal S, Wei B, Liu Y, An J. Bombus terrestris Prefer Mixed-Pollen Diets for a Better Colony Performance: A Laboratory Study. INSECTS 2024; 15:285. [PMID: 38667415 PMCID: PMC11049852 DOI: 10.3390/insects15040285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/24/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024]
Abstract
Pollen is a major source of proteins and lipids for bumblebees. The nutritional content of pollen may differ from source plants, ultimately affecting colony development. This study investigated the foraging preferences of Bombus terrestris in regard to four pollen species, i.e., oilseed rape, wild apricot, sunflower, and buckwheat, under laboratory conditions. The results show that B. terrestris diversified their preference for pollens; the bumblebees mostly preferred wild apricot pollen, whereas sunflower pollen was the least preferred. The colonies fed on a mixed four-pollen diet, with a protein-lipid ratio of 4.55-4.86, exhibited better development in terms of the number of offspring, individual body size and colony weight. The colonies fed with buckwheat and sunflower pollens produced a significantly lower number of workers and failed to produce queen and male offspring. Moreover, wild apricot pollen had the richest protein content (23.9 g/100 g) of the four pollen species, whereas oilseed rape pollen had the highest lipid content (6.7 g/100 g), as revealed by the P:L ratios of wild apricot, sunflower, buckwheat, and oilseed rape, which were 6.76, 5.52, 3.50, and 3.37, respectively. Generally, B. terrestris showed feeding preferences regarding different pollens and a mixture of pollens, which ultimately resulted in differences in colony development. The findings of this study provide important baseline information to researchers and developers of nutritive pollen diets for bumblebees.
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Affiliation(s)
- Ziyu Zhou
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Hong Zhang
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Shibonage K. Mashilingi
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
- Department of Crop Sciences and Beekeeping Technology, College of Agriculture and Food Technology, University of Dar es Salaam, P.O.BOX 35091, Dar es Salaam, Tanzania
| | - Chunting Jie
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Baodi Guo
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Yi Guo
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Xiao Hu
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Shahid Iqbal
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Bingshuai Wei
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Yanjie Liu
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
| | - Jiandong An
- State Key Laboratory of Resource Insects, Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Z.Z.); (H.Z.); (S.K.M.); (C.J.); (B.G.); (Y.G.); (X.H.); (S.I.); (B.W.)
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10
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Feng HH, Lv XW, Yang XC, Huang SQ. High toxin concentration in pollen may deter collection by bees in butterfly-pollinated Rhododendron molle. ANNALS OF BOTANY 2024:mcae047. [PMID: 38507570 DOI: 10.1093/aob/mcae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Indexed: 03/22/2024]
Abstract
BACKGROUNDS AND AIMS The hypothesis that plants evolve features that protect accessible pollen from consumption by flower visitors remains poorly understood. METHODS To explore potential chemical defenses against pollen consumption, we examined the pollinator assemblage, foraging behaviour, visitation frequency and pollen transfer efficiency in Rhododendron molle, a highly toxic shrub containing Rhodojaponin III. Nutrient (protein and lipid) and toxic components in pollen and other tissues were measured. KEY RESULTS Overall in the five populations, floral visits by butterflies and bumblebees were relatively more frequent than visits by honeybees. All foraged for nectar but not pollen. Butterflies did not differ from bumblebees in the amount of pollen removed per visit, but deposited more pollen per visit. Pollination experiments indicated that R. molle was self-compatible, but both fruit and seed production were pollen limited. Our analysis indicated that the pollen was not protein-poor and had a higher concentration of the toxic compound Rhodojaponin III than petals and leaves, which compound was undetectable in nectar. CONCLUSION Pollen toxicity in Rhododendron flowers may discourage pollen robbers (bees) from taking the freely accessible pollen grains, while the toxin-free nectar rewards effective pollinators, promoting pollen transfer. This preliminary study supports the hypothesis that chemical defense in pollen would be likely to evolve in species without physical protection from pollinivores.
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Affiliation(s)
- Hui-Hui Feng
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
- Department of Ecology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiao-Wen Lv
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Xiao-Chen Yang
- College of Biology and Environmental Sciences, Jishou University, Jishou 416000, Hunan Province, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
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11
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Rivest S, Muralidhar M, Forrest JRK. Pollen chemical and mechanical defences restrict host-plant use by bees. Proc Biol Sci 2024; 291:20232298. [PMID: 38471551 PMCID: PMC10932708 DOI: 10.1098/rspb.2023.2298] [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: 10/10/2023] [Accepted: 01/31/2024] [Indexed: 03/14/2024] Open
Abstract
Plants produce an array of chemical and mechanical defences that provide protection against many herbivores and pathogens. Putatively defensive compounds and structures can even occur in floral rewards: for example, the pollen of some plant taxa contains toxic compounds or possesses conspicuous spines. Yet little is known about whether pollen defences restrict host-plant use by bees. In other words, do bees, like other insect herbivores, tolerate the defences of their specific host plants while being harmed by non-host defences? To answer this question, we compared the effects of a chemical defence from Lupinus (Fabaceae) pollen and a putative mechanical defence (pollen spines) from Asteraceae pollen on larval survival of nine bee species in the tribe Osmiini (Megachilidae) varying in their pollen-host use. We found that both types of pollen defences reduce larval survival rate in some bee species. These detrimental effects were, however, mediated by host-plant associations, with bees being more tolerant of the pollen defences of their hosts, relative to the defences of plant taxa exploited by other species. This pattern strongly suggests that bees are adapted to the pollen defences of their hosts, and that host-plant use by bees is constrained by their ability to tolerate such defences.
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Affiliation(s)
- Sébastien Rivest
- Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | | | - Jessica R. K. Forrest
- Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
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12
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Paré PSL, Hien DFDS, Youba M, Yerbanga RS, Cohuet A, Gouagna L, Diabaté A, Ignell R, Dabiré RK, Gnankiné O, Lefèvre T. The paradox of plant preference: The malaria vectors Anopheles gambiae and Anopheles coluzzii select suboptimal food sources for their survival and reproduction. Ecol Evol 2024; 14:e11187. [PMID: 38533352 PMCID: PMC10963300 DOI: 10.1002/ece3.11187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/02/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
Anopheles gambiae and Anopheles coluzzii mosquitoes, two major malaria vectors in sub-Saharan Africa, exhibit selectivity among plant species as potential food sources. However, it remains unclear if their preference aligns with optimal nutrient intake and survival. Following an extensive screening of the effects of 31 plant species on An. coluzzii in Burkina Faso, we selected three species for their contrasting effects on mosquito survival, namely Ixora coccinea, Caesalpinia pulcherrima, and Combretum indicum. We assessed the sugar content of these plants and their impact on mosquito fructose positivity, survival, and insemination rate, using Anopheles coluzzii and Anopheles gambiae, with glucose 5% and water as controls. Plants displayed varying sugar content and differentially affected the survival, sugar intake, and insemination rate of mosquitoes. All three plants were more attractive to mosquitoes than controls, with An. gambiae being more responsive than An. coluzzii. Notably, C. indicum was the most attractive but had the lowest sugar content and offered the lowest survival, insemination rate, and fructose positivity. Our findings unveil a performance-preference mismatch in An. coluzzii and An. gambiae regarding plant food sources. Several possible reasons for this negative correlation between performance and preference are discussed.
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Affiliation(s)
- Prisca S. L. Paré
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- MIVEGEC, Université de Montpellier, IRD, CNRSMontpellierFrance
- Laboratoire d'Entomologie Fondamentale et Appliquée (LEFA), Unité de Formation et de Recherche—Sciences de la Vie et de la Terre (UFR‐SVT)Université Joseph KI‐ZERBO (UJKZ)OuagadougouBurkina Faso
| | - Domonbabele F. D. S. Hien
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- MIVEGEC, Université de Montpellier, IRD, CNRSMontpellierFrance
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
| | - Mariam Youba
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- MIVEGEC, Université de Montpellier, IRD, CNRSMontpellierFrance
- Laboratoire d'Entomologie Fondamentale et Appliquée (LEFA), Unité de Formation et de Recherche—Sciences de la Vie et de la Terre (UFR‐SVT)Université Joseph KI‐ZERBO (UJKZ)OuagadougouBurkina Faso
| | - Rakiswendé S. Yerbanga
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
- Institut Des Sciences et Techniques (INSTech—BOBO)Bobo‐DioulassoBurkina Faso
| | - Anna Cohuet
- MIVEGEC, Université de Montpellier, IRD, CNRSMontpellierFrance
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
| | | | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Disease Vector GroupSwedish University of Agricultural SciencesUppsalaSweden
| | - Roch K. Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
| | - Olivier Gnankiné
- Laboratoire d'Entomologie Fondamentale et Appliquée (LEFA), Unité de Formation et de Recherche—Sciences de la Vie et de la Terre (UFR‐SVT)Université Joseph KI‐ZERBO (UJKZ)OuagadougouBurkina Faso
| | - Thierry Lefèvre
- Institut de Recherche en Sciences de la Santé (IRSS)Bobo‐DioulassoBurkina Faso
- MIVEGEC, Université de Montpellier, IRD, CNRSMontpellierFrance
- Laboratoire Mixte International Sur les Vecteurs (LAMIVECT)Bobo‐DioulassoBurkina Faso
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13
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Li J, Hu H, Fu H, Li J, Zeng T, Li J, Wang M, Jongsma MA, Wang C. Exploring the co-operativity of secretory structures for defense and pollination in flowering plants. PLANTA 2024; 259:41. [PMID: 38270671 DOI: 10.1007/s00425-023-04322-w] [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: 07/11/2023] [Accepted: 12/24/2023] [Indexed: 01/26/2024]
Abstract
MAIN CONCLUSION In flowers multiple secretory systems cooperate to deliver specialized metabolites to support specific roles in defence and pollination. The collective roles of cell types, enzymes, and transporters are discussed. The interplay between reproductive strategies and defense mechanisms in flowering plants has long been recognized, with trade-offs between investment in defense and reproduction predicted. Glandular trichomes and secretory cavities or ducts, which are epidermal and internal structures, play a pivotal role in the secretion, accumulation, and transport of specialized secondary metabolites, and contribute significantly to defense and pollination. Recent investigations have revealed an intricate connection between these two structures, whereby specialized volatile and non-volatile metabolites are exchanged, collectively shaping their respective ecological functions. However, a comprehensive understanding of this profound integration remains largely elusive. In this review, we explore the secretory systems and associated secondary metabolism primarily in Asteraceous species to propose potential shared mechanisms facilitating the directional translocation of these metabolites to diverse destinations. We summarize recent advances in our understanding of the cooperativity between epidermal and internal secretory structures in the biosynthesis, secretion, accumulation, and emission of terpenes, providing specific well-documented examples from pyrethrum (Tanacetum cinerariifolium). Pyrethrum is renowned for its natural pyrethrin insecticides, which accumulate in the flower head, and more recently, for emitting an aphid alarm pheromone. These examples highlight the diverse specializations of secondary metabolism in pyrethrum and raise intriguing questions regarding the regulation of production and translocation of these compounds within and between its various epidermal and internal secretory systems, spanning multiple tissues, to serve distinct ecological purposes. By discussing the cooperative nature of secretory structures in flowering plants, this review sheds light on the intricate mechanisms underlying the ecological roles of terpenes in defense and pollination.
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Affiliation(s)
- Jinjin Li
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Hu
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China
| | - Hansen Fu
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China
| | - Jie Li
- Guangdong Provincial Key Lab of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Tuo Zeng
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiawen Li
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China
| | - Manqun Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Maarten A Jongsma
- Business Unit Bioscience, Wageningen Plant Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
| | - Caiyun Wang
- National Key Laboratory for Germplasm Innovation, Unifilization of Horticultural Crops Huazhong Agricultural University, Wuhan, 430070, China.
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14
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Vaudo AD, Dyer LA, Leonard AS. Pollen nutrition structures bee and plant community interactions. Proc Natl Acad Sci U S A 2024; 121:e2317228120. [PMID: 38190523 PMCID: PMC10801918 DOI: 10.1073/pnas.2317228120] [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: 10/09/2023] [Accepted: 11/19/2023] [Indexed: 01/10/2024] Open
Abstract
As bees' main source of protein and lipids, pollen is critical for their development, reproduction, and health. Plant species vary considerably in the macronutrient content of their pollen, and research in bee model systems has established that this variation both modulates performance and guides floral choice. Yet, how variation in pollen chemistry shapes interactions between plants and bees in natural communities is an open question, essential for both understanding the nutritional dynamics of plant-pollinator mutualisms and informing their conservation. To fill this gap, we asked how pollen nutrition (relative protein and lipid content) sampled from 109 co-flowering plant species structured visitation patterns observed among 75 subgenera of pollen-collecting bees in the Great Basin/Eastern Sierra region (USA). We found that the degree of similarity in co-flowering plant species' pollen nutrition predicted similarity among their visitor communities, even after accounting for floral morphology and phylogeny. Consideration of pollen nutrition also shed light on the structure of this interaction network: Bee subgenera and plant genera were arranged into distinct, interconnected groups, delineated by differences in pollen macronutrient values, revealing potential nutritional niches. Importantly, variation in pollen nutrition alone (high in protein, high in lipid, or balanced) did not predict the diversity of bee visitors, indicating that plant species offering complementary pollen nutrition may be equally valuable in supporting bee diversity. Nutritional diversity should thus be a key consideration when selecting plants for habitat restoration, and a nutritionally explicit perspective is needed when considering reward systems involved in the community ecology of pollination.
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Affiliation(s)
- Anthony D. Vaudo
- Department of Biology, University of Nevada, Reno, NV89557
- Rocky Mountain Research Station, United States Department of Agriculture Forest Service, Moscow, ID83843
| | - Lee A. Dyer
- Department of Biology, University of Nevada, Reno, NV89557
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15
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Burger H, Buttala S, Koch H, Ayasse M, Johnson SD, Stevenson PC. Nectar cardenolides and floral volatiles mediate a specialized wasp pollination system. J Exp Biol 2024; 227:jeb246156. [PMID: 38180227 PMCID: PMC10785657 DOI: 10.1242/jeb.246156] [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: 05/21/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024]
Abstract
Specialization in plant pollination systems can arise from traits that function as filters of flower visitors. This may involve chemical traits such as floral volatiles that selectively attract favoured visitors and non-volatile nectar constituents that selectively deter disfavoured visitors through taste or longer-term toxic effects or both. We explored the functions of floral chemical traits in the African milkweed Gomphocarpus physocarpus, which is pollinated almost exclusively by vespid wasps, despite having nectar that is highly accessible to other insects such as honeybees. We demonstrated that the nectar of wasp-pollinated G. physocarpus contains cardenolides that had greater toxic effects on Apis mellifera honeybees than on Vespula germanica wasps, and also reduced feeding rates by honeybees. Behavioural experiments using natural compositions of nectar compounds showed that these interactions are mediated by non-volatile nectar chemistry. We also identified volatile compounds with acetic acid as a main component in the floral scent of G. physocarpus that elicited electrophysiological responses in wasp antennae. Mixtures of these compounds were behaviourally effective for attraction of V. germanica wasps. The results show the importance of both volatile and non-volatile chemical traits as filters that lead to specialization in plant pollination systems.
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Affiliation(s)
- Hannah Burger
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Samantha Buttala
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Hauke Koch
- Royal Botanic Gardens, Kew,Kew Green, Richmond TW9 3AE, UK
| | - Manfred Ayasse
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Steven D. Johnson
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg 3209, South Africa
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew,Kew Green, Richmond TW9 3AE, UK
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
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16
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Wang X, Yao R, Lv X, Yi Y, Tang X. Nectar robbing by bees affects the reproductive fitness of the distylous plant Tirpitzia sinensis (Linaceae). Ecol Evol 2023; 13:e10714. [PMID: 37953984 PMCID: PMC10638493 DOI: 10.1002/ece3.10714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/14/2023] Open
Abstract
Nectar robbing can affect plant reproductive success directly by influencing female and male fitness, and indirectly by affecting pollinator behavior. Flowers have morphological and chemical features that may protect them from nectar robbers. Previous studies on nectar robbing have focused mainly on homotypic plants. It remains unclear how nectar robbing affects the reproductive success of distylous plants, and whether defense strategies of two morphs are different. Nectar-robbing rates on the long- and short-styled morph (L-morph, S-morph) of the distylous Tirpitzia sinensis were investigated. We compared floral traits, the temporal pattern of change in nectar volume and sugar concentration, nectar secondary metabolites, and sugar composition between robbed and unrobbed flowers of two morphs. We tested direct effects of nectar robbing on female and male components of plant fitness and indirect effects of nectar robbing via pollinators. Nectar-robbing rates did not differ between the two morphs. Flowers with smaller sepals and petals were more easily robbed. The floral tube diameter and thickness were greater in L-morphs than in S-morphs, and the nectar rob holes were significantly smaller in L-morphs than in S-morphs. Nectar robbing significantly decreased nectar replenishment rate but did not affect nectar sugar concentration or sugar composition. After robbery, the quantities and diversity of secondary compounds in the nectar of S-morphs increased significantly and total relative contents of secondary compounds in L-morphs showed no obvious changes. Nectar robbing could decrease female fitness by decreasing pollen germination rate and thus decreasing seed set. Nectar robbing had no significant effects on male fitness. Robbed flowers were less likely to be visited by hawkmoth pollinators, especially in S-morphs. These results suggest that nectar robbing could directly and indirectly decrease the female fitness of T. sinensis, and different morphs have evolved different defense mechanisms in response to nectar-robbing pressure.
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Affiliation(s)
- Xiaoyue Wang
- Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern ChinaGuizhou Normal UniversityGuiyangChina
- School of Life SciencesGuizhou Normal UniversityGuiyangChina
| | - Renxiu Yao
- Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern ChinaGuizhou Normal UniversityGuiyangChina
- School of Life SciencesGuizhou Normal UniversityGuiyangChina
| | - Xiaoqin Lv
- Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern ChinaGuizhou Normal UniversityGuiyangChina
- School of Life SciencesGuizhou Normal UniversityGuiyangChina
| | - Yin Yi
- Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern ChinaGuizhou Normal UniversityGuiyangChina
- School of Life SciencesGuizhou Normal UniversityGuiyangChina
| | - Xiaoxin Tang
- Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern ChinaGuizhou Normal UniversityGuiyangChina
- School of Life SciencesGuizhou Normal UniversityGuiyangChina
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17
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Palmer-Young EC, Markowitz LM, Huang WF, Evans JD. High temperatures augment inhibition of parasites by a honey bee gut symbiont. Appl Environ Microbiol 2023; 89:e0102323. [PMID: 37791764 PMCID: PMC10617414 DOI: 10.1128/aem.01023-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/02/2023] [Indexed: 10/05/2023] Open
Abstract
Temperature affects growth, metabolism, and interspecific interactions in microbial communities. Within animal hosts, gut bacterial symbionts can provide resistance to parasitic infections. Both infection and populations of symbionts can be shaped by the host body temperature. However, the effects of temperature on the antiparasitic activities of gut symbionts have seldom been explored. The Lactobacillus-rich gut microbiota of facultatively endothermic honey bees is subject to seasonal and ontogenetic changes in host temperature that could alter the effects of symbionts against parasites. We used cell cultures of a Lactobacillus symbiont and an important trypanosomatid gut parasite of honey bees to test the potential for temperature to shape parasite-symbiont interactions. We found that symbionts showed greater heat tolerance than parasites and chemically inhibited parasite growth via production of acids. Acceleration of symbiont growth and acid production at high temperatures resulted in progressively stronger antiparasitic effects across a temperature range typical of bee colonies. Consequently, the presence of symbionts reduced both the peak growth rate and heat tolerance of parasites. Substantial changes in parasite-symbiont interactions were evident over a temperature breadth that parallels changes in diverse animals exhibiting infection-related fevers and the amplitude of circadian temperature variation typical of endothermic birds and mammals, implying the frequent potential for temperature to alter symbiont-mediated resistance to parasites in endo- and ectothermic hosts. Results suggest that the endothermic behavior of honey bees could enhance the impacts of gut symbionts on parasites, implicating thermoregulation as a reinforcer of core symbioses and possibly microbiome-mediated antiparasitic defense. IMPORTANCE Two factors that shape the resistance of animals to infection are body temperature and gut microbiota. However, temperature can also alter interactions among microbes, raising the question of whether and how temperature changes the antiparasitic effects of gut microbiota. Honey bees are agriculturally important hosts of diverse parasites and infection-mitigating gut microbes. They can also socially regulate their body temperatures to an extent unusual for an insect. We show that high temperatures found in honey bee colonies augment the ability of a gut bacterial symbiont to inhibit the growth of a common bee parasite, reducing the parasite's ability to grow at high temperatures. This suggests that fluctuations in colony and body temperatures across life stages and seasons could alter the protective value of bees' gut microbiota against parasites, and that temperature-driven changes in gut microbiota could be an underappreciated mechanism by which temperature-including endothermy and fever-alters animal infection.
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Affiliation(s)
| | - Lindsey M. Markowitz
- USDA-ARS Bee Research Lab, Beltsville, Maryland, USA
- Department of Biology, University of Maryland, College Park, Maryland, USA
| | | | - Jay D. Evans
- USDA-ARS Bee Research Lab, Beltsville, Maryland, USA
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18
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Sasidharan R, Junker RR, Eilers EJ, Müller C. Floral volatiles evoke partially similar responses in both florivores and pollinators and are correlated with non-volatile reward chemicals. ANNALS OF BOTANY 2023; 132:1-14. [PMID: 37220889 PMCID: PMC10550281 DOI: 10.1093/aob/mcad064] [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: 02/16/2023] [Accepted: 05/19/2023] [Indexed: 05/25/2023]
Abstract
BACKGROUND Plants often use floral displays to attract mutualists and prevent antagonist attacks. Chemical displays detectable from a distance include attractive or repellent floral volatile organic compounds (FVOCs). Locally, visitors perceive contact chemicals including nutrients but also deterrent or toxic constituents of pollen and nectar. The FVOC and pollen chemical composition can vary intra- and interspecifically. For certain pollinator and florivore species, responses to these compounds are studied in specific plant systems, yet we lack a synthesis of general patterns comparing these two groups and insights into potential correlations between FVOC and pollen chemodiversity. SCOPE We reviewed how FVOCs and non-volatile floral chemical displays, i.e. pollen nutrients and toxins, vary in composition and affect the detection by and behaviour of insect visitors. Moreover, we used meta-analyses to evaluate the detection of and responses to FVOCs by pollinators vs. florivores within the same plant genera. We also tested whether the chemodiversity of FVOCs, pollen nutrients and toxins is correlated, hence mutually informative. KEY RESULTS According to available data, florivores could detect more FVOCs than pollinators. Frequently tested FVOCs were often reported as pollinator-attractive and florivore-repellent. Among FVOCs tested on both visitor groups, there was a higher number of attractive than repellent compounds. FVOC and pollen toxin richness were negatively correlated, indicating trade-offs, whereas a marginal positive correlation between the amount of pollen protein and toxin richness was observed. CONCLUSIONS Plants face critical trade-offs, because floral chemicals mediate similar information to both mutualists and antagonists, particularly through attractive FVOCs, with fewer repellent FVOCs. Furthermore, florivores might detect more FVOCs, whose richness is correlated with the chemical richness of rewards. Chemodiversity of FVOCs is potentially informative of reward traits. To gain a better understanding of the ecological processes shaping floral chemical displays, more research is needed on floral antagonists of diverse plant species and on the role of floral chemodiversity in visitor responses.
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Affiliation(s)
- Rohit Sasidharan
- Department of Chemical Ecology, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Robert R Junker
- Department of Biology, Evolutionary Ecology of Plants, University of Marburg, Karl-von-Frisch-Straße 8, 35043 Marburg, Germany
- Department of Environment and Biodiversity, University of Salzburg, Kapitalgasse 4-6, 5020 Salzburg, Austria
| | - Elisabeth J Eilers
- Department of Chemical Ecology, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
- CTL GmbH Bielefeld, Krackser Straße 12, 33659 Bielefeld, Germany
| | - Caroline Müller
- Department of Chemical Ecology, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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19
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Leponiemi M, Freitak D, Moreno-Torres M, Pferschy-Wenzig EM, Becker-Scarpitta A, Tiusanen M, Vesterinen EJ, Wirta H. Honeybees' foraging choices for nectar and pollen revealed by DNA metabarcoding. Sci Rep 2023; 13:14753. [PMID: 37679501 PMCID: PMC10484984 DOI: 10.1038/s41598-023-42102-4] [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: 05/12/2023] [Accepted: 09/05/2023] [Indexed: 09/09/2023] Open
Abstract
Honeybees are the most widespread managed pollinators of our food crops, and a crucial part of their well-being is a suitable diet. Yet, we do not know how they choose flowers to collect nectar or pollen from. Here we studied forty-three honeybee colonies in six apiaries over a summer, identifying the floral origins of honey and hive-stored pollen samples by DNA-metabarcoding. We recorded the available flowering plants and analyzed the specialized metabolites in honey. Overall, we find that honeybees use mostly the same plants for both nectar and pollen, yet per colony less than half of the plant genera are used for both nectar and pollen at a time. Across samples, on average fewer plant genera were used for pollen, but the composition was more variable among samples, suggesting higher selectivity for pollen sources. Of the available flowering plants, honeybees used only a fraction for either nectar or pollen foraging. The time of summer guided the plant choices the most, and the location impacted both the plants selected and the specialized metabolite composition in honey. Thus, honeybees are selective for both nectar and pollen, implicating a need of a wide variety of floral resources to choose an optimal diet from.
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Affiliation(s)
- Matti Leponiemi
- Institute of Biology, Karl-Franzen University of Graz, Universitätsplatz 2, 8010, Graz, Austria
| | - Dalial Freitak
- Institute of Biology, Karl-Franzen University of Graz, Universitätsplatz 2, 8010, Graz, Austria
| | - Miguel Moreno-Torres
- Institute of Environmental Systems Science, Karl-Franzens-Universität Graz, Merangasse 18/I, 8010, Graz, Austria
| | - Eva-Maria Pferschy-Wenzig
- Institute of Pharmaceutical Sciences, Pharmacognosy, University of Graz, Beethovenstraße 8, Graz, Austria
| | | | - Mikko Tiusanen
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
- Department of Agricultural Sciences, University of Helsinki, Latokartanonkaari 5, P.O. Box 27, 00014, Helsinki, Finland
| | - Eero J Vesterinen
- Department of Biology, University of Turku, Vesilinnantie 5, Turku, Finland
| | - Helena Wirta
- Department of Agricultural Sciences, University of Helsinki, Latokartanonkaari 5, P.O. Box 27, 00014, Helsinki, Finland.
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20
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Bernklau E, Arathi HS. Seasonal patterns of beneficial phytochemical availability in honey and stored pollen from honey bee colonies in large apiaries. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:1069-1077. [PMID: 37247384 DOI: 10.1093/jee/toad096] [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: 12/04/2022] [Revised: 04/24/2023] [Accepted: 05/10/2023] [Indexed: 05/31/2023]
Abstract
Honey bees (Apis mellifera L.; Hymenoptera, Apidae) are the most efficient pollinators in agroecosystems, responsible for the successful production of fruits, nuts, and vegetables, but they continue to face debilitating challenges. One of the major factors leading to these challenges could be linked to poor nutrition that results in weakening the colony, increasing susceptibility to pests and pathogens, and reducing the ability of bees to adapt to other abiotic stresses. Extensively used for commercial pollination, honey bee colonies regularly face exposure to limited diversity in their pollen diet as they are placed in flowering monocrops. Lack of access to diverse plant species compromises the availability of plant secondary compounds (phytochemicals), which, in small amounts, provide significant benefits to honey bee health. We analyzed the beneficial phytochemical content of honey and stored pollen (bee bread) samples from colonies in large apiaries through the active bee season. Samples were evaluated for 4 beneficial phytochemicals (caffeine, kaempferol, gallic acid, and p-coumaric acid), which have previously been shown to improve honey bee health. Our results, as relevant to the apiary locations in the study, indicated that p-coumaric acid is uniformly available throughout the season. Caffeine is completely absent, and gallic acid and kaempferol are not regularly available. Our results suggest the need to explore the potential to deliver beneficial phytochemicals as nutritional supplements to improve bee health. It may be vital for the pollination industry to consider such targeted dietary supplementation as beekeepers strive to meet the increasing demand for crop pollination services.
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Affiliation(s)
- Elisa Bernklau
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80525, USA
| | - H S Arathi
- Invasive Species and Pollinator Health Research Unit, USDA-ARS, Davis, CA 95616, USA
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Rutkowski D, Weston M, Vannette RL. Bees just wanna have fungi: a review of bee associations with nonpathogenic fungi. FEMS Microbiol Ecol 2023; 99:fiad077. [PMID: 37422442 PMCID: PMC10370288 DOI: 10.1093/femsec/fiad077] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/15/2023] [Accepted: 07/06/2023] [Indexed: 07/10/2023] Open
Abstract
Bee-fungus associations are common, and while most studies focus on entomopathogens, emerging evidence suggests that bees associate with a variety of symbiotic fungi that can influence bee behavior and health. Here, we review nonpathogenic fungal taxa associated with different bee species and bee-related habitats. We synthesize results of studies examining fungal effects on bee behavior, development, survival, and fitness. We find that fungal communities differ across habitats, with some groups restricted mostly to flowers (Metschnikowia), while others are present almost exclusively in stored provisions (Zygosaccharomyces). Starmerella yeasts are found in multiple habitats in association with many bee species. Bee species differ widely in the abundance and identity of fungi hosted. Functional studies suggest that yeasts affect bee foraging, development, and pathogen interactions, though few bee and fungal taxa have been examined in this context. Rarely, fungi are obligately beneficial symbionts of bees, whereas most are facultative bee associates with unknown or ecologically contextual effects. Fungicides can reduce fungal abundance and alter fungal communities associated with bees, potentially disrupting bee-fungi associations. We recommend that future study focus on fungi associated with non-honeybee species and examine multiple bee life stages to document fungal composition, abundance, and mechanistic effects on bees.
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Affiliation(s)
- Danielle Rutkowski
- 367 Briggs Hall, Department of Entomology and Nematology, University of California Davis, Davis, CA 95616, United States
| | - Makena Weston
- 367 Briggs Hall, Department of Entomology and Nematology, University of California Davis, Davis, CA 95616, United States
| | - Rachel L Vannette
- 367 Briggs Hall, Department of Entomology and Nematology, University of California Davis, Davis, CA 95616, United States
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22
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Russo L, Ruedenauer F, Gronert A, Van de Vreken I, Vanderplanck M, Michez D, Klein A, Leonhardt S, Stout JC. Fertilizer and herbicide alter nectar and pollen quality with consequences for pollinator floral choices. PeerJ 2023; 11:e15452. [PMID: 37334137 PMCID: PMC10269573 DOI: 10.7717/peerj.15452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/03/2023] [Indexed: 06/20/2023] Open
Abstract
Background Pollinating insects provide economically and ecologically valuable services, but are threatened by a variety of anthropogenic changes. The availability and quality of floral resources may be affected by anthropogenic land use. For example, flower-visiting insects in agroecosystems rely on weeds on field edges for foraging resources, but these weeds are often exposed to agrochemicals that may compromise the quality of their floral resources. Methods We conducted complementary field and greenhouse experiments to evaluate the: (1) effect of low concentrations of agrochemical exposure on nectar and pollen quality and (2) relationship between floral resource quality and insect visitation. We applied the same agrochemcial treatments (low concentrations of fertilizer, low concentrations of herbicide, a combination of both, and a control of just water) to seven plant species in the field and greenhouse. We collected data on floral visitation by insects in the field experiment for two field seasons and collected pollen and nectar from focal plants in the greenhouse to avoid interfering with insect visitation in the field. Results We found pollen amino acid concentrations were lower in plants exposed to low concentrations of herbicide, and pollen fatty acid concentrations were lower in plants exposed to low concentrations of fertilizer, while nectar amino acids were higher in plants exposed to low concentrations of either fertilizer or herbicide. Exposure to low fertilizer concentrations also increased the quantity of pollen and nectar produced per flower. The responses of plants exposed to the experimental treatments in the greenhouse helped explain insect visitation in the field study. The insect visitation rate correlated with nectar amino acids, pollen amino acids, and pollen fatty acids. An interaction between pollen protein and floral display suggested pollen amino acid concentrations drove insect preference among plant species when floral display sizes were large. We show that floral resource quality is sensitive to agrochemical exposure and that flower-visiting insects are sensitive to variation in floral resource quality.
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Affiliation(s)
- Laura Russo
- University of Tennessee, Knoxville, United States of America
- Trinity College Dublin, Dublin, Ireland
| | | | - Angela Gronert
- Chair of Nature Conservation and Landscape Ecology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | | | | | | | - Alexandra Klein
- Chair of Nature Conservation and Landscape Ecology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
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Mueller TG, Francis JS, Vannette RL. Nectar compounds impact bacterial and fungal growth and shift community dynamics in a nectar analog. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:170-180. [PMID: 36779256 PMCID: PMC10464699 DOI: 10.1111/1758-2229.13139] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 12/04/2022] [Indexed: 05/06/2023]
Abstract
Floral nectar is frequently colonised by microbes. However, nectar microbial communities are typically species-poor and dominated by few cosmopolitan genera. One hypothesis is that nectar constituents may act as environmental filters. We tested how five non-sugar nectar compounds as well as elevated sugar impacted the growth of 12 fungal and bacterial species isolated from nectar, pollinators, and the environment. We hypothesised that nectar isolated microbes would have the least growth suppression. Additionally, to test if nectar compounds could affect the outcome of competition between microbes, we grew a subset of microbes in co-culture across a subset of treatments. We found that some compounds such as H2 O2 suppressed microbial growth across many but not all microbes tested. Other compounds were more specialised in the microbes they impacted. As hypothesised, the nectar specialist yeast Metschnikowia reukaufii was unaffected by most nectar compounds assayed. However, many non-nectar specialist microbes remained unaffected by nectar compounds thought to reduce microbial growth. Our results show that nectar chemistry can influence microbial communities but that microbe-specific responses to nectar compounds are common. Nectar chemistry also affected the outcome of species interactions among microbial taxa, suggesting that non-sugar compounds can affect microbial community assembly in flowers.
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Affiliation(s)
- Tobias G. Mueller
- Department of Entomology and NematologyUniversity of California, DavisDavisCaliforniaUSA
- Department of EntomologyCornell UniversityIthacaNew YorkUSA
| | - Jacob S. Francis
- Department of Entomology and NematologyUniversity of California, DavisDavisCaliforniaUSA
| | - Rachel L. Vannette
- Department of Entomology and NematologyUniversity of California, DavisDavisCaliforniaUSA
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24
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Fattorini R, Egan PA, Rosindell J, Farrell IW, Stevenson PC. Grayanotoxin I variation across tissues and species of Rhododendron suggest pollinator-herbivore defence trade-offs. PHYTOCHEMISTRY 2023; 212:113707. [PMID: 37149121 DOI: 10.1016/j.phytochem.2023.113707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023]
Abstract
Grayanotoxin I (GTX I) is a major toxin in leaves of Rhododendron species, where it provides a defence against insect and vertebrate herbivores. Surprisingly, it is also present in R. ponticum nectar, and this can hold important implications for plant-pollinator mutualisms. However, knowledge of GTX I distributions across the genus Rhododendron and in different plant materials is currently limited, despite the important ecological function of this toxin. Here we characterise GTX I expression in the leaves, petals, and nectar of seven Rhododendron species. Our results indicated interspecific variation in GTX I concentration across all species. GTX I concentrations were consistently higher in leaves compared to petals and nectar. Our findings provide preliminary evidence for phenotypic correlation between GTX I concentrations in defensive tissues (leaves and petals) and floral rewards (nectar), suggesting that Rhododendron species may commonly experience functional trade-offs between herbivore defence and pollinator attraction.
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Affiliation(s)
- Róisín Fattorini
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
| | - Paul A Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, Alnarp 23053, Sweden
| | - James Rosindell
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
| | - Iain W Farrell
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE UK; Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK
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25
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Nebauer CA, Schleifer MC, Ruedenauer FA, Leonhardt SD, Spaethe J. Perception, regulation, and fitness effects of pollen phytosterols in the bumble bee, Bombus terrestris. AMERICAN JOURNAL OF BOTANY 2023:e16165. [PMID: 37071779 DOI: 10.1002/ajb2.16165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 06/19/2023]
Abstract
PREMISE Many flowering plants depend on insects for pollination and thus attract pollinators by offering rewards, mostly nectar and pollen. Bee pollinators rely on pollen as their main nutrient source. Pollen provides all essential micro- and macronutrients including substances that cannot be synthesized by bees themselves, such as sterols, which bees need for processes such as hormone production. Variations in sterol concentrations may consequently affect bee health and reproductive fitness. We therefore hypothesized that (1) these variations in pollen sterols affect longevity and reproduction in bumble bees and (2) can thus be perceived via the bees' antennae before consumption. METHODS We studied the effect of sterols on longevity and reproduction of Bombus terrestris workers in feeding experiments and investigated sterol perception using chemotactile proboscis extension response (PER) conditioning. RESULTS Workers could perceive several sterols (cholesterol, cholestenone, desmosterol, stigmasterol, β-sitosterol) via their antennae but not differentiate between them. However, when sterols were presented in pollen, and not as a single compound, the bees were unable to differentiate between pollen differing in sterol content. Additionally, different sterol concentrations in pollen neither affected pollen consumption nor brood development or worker longevity. CONCLUSIONS Since we used both natural concentrations and concentrations higher than those found in pollen, our results indicate that bumble bees may not need to pay specific attention to pollen sterol content beyond a specific threshold. Naturally encountered concentrations might fully support their sterol requirements and higher concentrations do not seem to have negative effects.
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Affiliation(s)
- Carmen A Nebauer
- Plant-Insect Interactions, Department of Life Science Systems, Technical University of Munich, Freising, Germany
| | - Marielle C Schleifer
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Fabian A Ruedenauer
- Plant-Insect Interactions, Department of Life Science Systems, Technical University of Munich, Freising, Germany
| | - Sara D Leonhardt
- Plant-Insect Interactions, Department of Life Science Systems, Technical University of Munich, Freising, Germany
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, Würzburg, Germany
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Palmer-Young EC, Malfi R, Zhou Y, Joyce B, Whitehead H, Van Wyk JI, Baylis K, Grubbs K, Boncristiani DL, Evans JD, Irwin RE, Adler LS. Sunflower-Associated Reductions in Varroa Mite Infestation of Honey Bee Colonies. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:68-77. [PMID: 36573405 DOI: 10.1093/jee/toac196] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Indexed: 06/18/2023]
Abstract
Landscapes can affect parasite epidemiology in wild and agricultural animals. Honey bees are threatened by loss of floral resources and by parasites, principally the mite Varroa destructor and the viruses it vectors. Existing mite control relies heavily on chemical treatments that can adversely affect bees. Alternative, pesticide-free control methods are needed to mitigate infestation with these ectoparasites. Many flowering plants provide nectar and pollen that confer resistance to parasites. Enrichment of landscapes with antiparasitic floral resources could therefore provide a sustainable means of parasite control in pollinators. Floral rewards of Asteraceae plants can reduce parasitic infection in diverse bee species, including honey and bumble bees. Here, we tested the effects of sunflower (Helianthus annuus) cropland and pollen supplementation on honey bee resistance to macro- and microparasites. Although sunflower had nonsignificant effects on microparasites, We found that increased sunflower pollen availability correlated with reduced Varroa mite infestation in landscapes and pollen-supplemented colonies. At the landscape level, each doubling of sunflower crop area was associated with a 28% reduction in mite infestation. In field trials, late-summer supplementation of colonies with sunflower pollen reduced mite infestation by 2.75-fold relative to artificial pollen. United States sunflower crop acreage has declined by 2% per year since 1980, however, suggesting reduced availability of this floral resource. Although further research is needed to determine whether the observed effects represent direct inhibition of mite fecundity or mite-limiting reductions in honey bee brood-rearing, our findings suggest the potential for sunflower plantings or pollen supplements to counteract a major driver of honey bee losses worldwide.
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Affiliation(s)
| | - Rosemary Malfi
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Yujun Zhou
- Department of Agricultural & Consumer Economics, University of Illinois at Urbana-Champaign, Urbana and Champaign, IL, USA
| | - Bryanna Joyce
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Hannah Whitehead
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Jennifer I Van Wyk
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Kathy Baylis
- Department of Agricultural & Consumer Economics, University of Illinois at Urbana-Champaign, Urbana and Champaign, IL, USA
| | - Kyle Grubbs
- USDA-ARS Bee Research Laboratory, Beltsville, MD, USA
| | | | - Jay D Evans
- USDA-ARS Bee Research Laboratory, Beltsville, MD, USA
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA
| | - Lynn S Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
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Barberis M, Calabrese D, Galloni M, Nepi M. Secondary Metabolites in Nectar-Mediated Plant-Pollinator Relationships. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12030550. [PMID: 36771634 PMCID: PMC9920422 DOI: 10.3390/plants12030550] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 06/01/2023]
Abstract
In recent years, our understanding of the complex chemistry of floral nectar and its ecological implications for plant-pollinator relationships has certainly increased. Nectar is no longer considered merely a reward for pollinators but rather a plant interface for complex interactions with insects and other organisms. A particular class of compounds, i.e., nectar secondary compounds (NSCs), has contributed to this new perspective, framing nectar in a more comprehensive ecological context. The aim of this review is to draft an overview of our current knowledge of NSCs, including emerging aspects such as non-protein amino acids and biogenic amines, whose presence in nectar was highlighted quite recently. After considering the implications of the different classes of NSCs in the pollination scenario, we discuss hypotheses regarding the evolution of such complex nectar profiles and provide cues for future research on plant-pollinator relationships.
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Affiliation(s)
- Marta Barberis
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - Daniele Calabrese
- Department of Life Sciences, University of Siena, Via P.A. Mattioli 4, 53100 Siena, Italy
| | - Marta Galloni
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - Massimo Nepi
- Department of Life Sciences, University of Siena, Via P.A. Mattioli 4, 53100 Siena, Italy
- National Biodiversity Future Centre (NBFC), 90123 Palermo, Italy
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Abstract
Stingless bees form perennial colonies of honey-making insects. The >600 species of stingless bees, mainly Neotropical, live throughout tropical latitudes. Foragers influence floral biology, plant reproduction, microbe dispersal, and diverse ecosystem functions. As tropical forest residents since the upper Cretaceous, they have had a long evolutionary history without competition from honey bees. Most stingless bees are smaller than any Apis species and recruit nest mates to resources, while their defense strategies exclude stinging behavior but incorporate biting. Stingless bees have diversified ecologically; excel in nesting site selection and mutualisms with plants, arthropods, and microbes; and display opportunism, including co-opting plant defenses. As their biology becomes better known, applications to human endeavors are imposing selective pressures from exploitation and approaches to conservation that entail colony extraction from wildlands. Although some meliponines can adjust to new conditions, their populations shall require tropical diversity for survival and reproduction.
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Affiliation(s)
- David W Roubik
- Smithsonian Tropical Research Institute, Balboa, Republic of Panamá;
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29
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Hao K, Xu Q, Huang SQ. Pollen-feeding behavior of diverse insects on Geranium delavayi, a flower with large, accessible pollen grains. AMERICAN JOURNAL OF BOTANY 2023; 110:e16113. [PMID: 36462154 DOI: 10.1002/ajb2.16113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
PREMISE Why have pollen grains evolved to be exceptionally large in some species? Pollen-feeding hypothesis suggests that if the proportion of pollen amounts for feeding is reduced in a flower, the low allocation to pollen number would allow pollen grains to be larger. METHODS To examine whether species with large pollen grains experience low pollen consumption, the behavior of insects feeding on nectar and pollen was observed and pollen transfer efficiency was estimated for four visitor types in Geranium delavayi. To see whether bees actively collected pollen, the numbers of grains in pollen baskets and on the body were compared. Both nutritional value (total protein and lipid) and chemical defense (phenolic metabolites) in pollen against pollen feeders were measured. RESULTS Bumblebees and honeybees foraged for nectar, rarely groomed pollen into corbiculae, and had >5× higher pollen transfer efficiency than smaller solitary bees and flies, which were pollen eaters that removed more pollen but deposited less. Pollen grains were characterized by low protein and high lipid content with a low protein-lipid ratio, an unfavorable combination for bumblebees. Three secondary metabolites were significantly higher in pollen grains (7.77 mg/g) than in petals (1.08 mg/g) or in nectar (0.44 mg/g), suggesting stronger chemical defense in pollen. CONCLUSIONS Our results indicated that large bees took nectar but little of the nutritionally poor and highly toxic pollen. These data support one prediction of the pollen-feeding hypothesis, that species with few and large pollen grains would also have low pollen-consumption rates.
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Affiliation(s)
- Kai Hao
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Qi Xu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
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30
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van der Kooi CJ, Spaethe J, Leonhardt SD. Editorial: Sensory ecology of plant-pollinator interactions. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1101114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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Gekière A, Michez D, Vanderplanck M. Bumble Bee Breeding on Artificial Pollen Substitutes. JOURNAL OF ECONOMIC ENTOMOLOGY 2022; 115:1423-1431. [PMID: 36000563 DOI: 10.1093/jee/toac126] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Bumble bees are important pollinators for many temperate crops. Because of the growing demand for food from entomophilous crops, bumble bee colonies are commercially reared and placed in fields or greenhouses to guarantee sufficient pollination services. Besides, commercial colonies are increasingly used in laboratories for various bioassays under controlled conditions. For both usages, bumble bee colonies are commonly provided with sugar solution and honey bee-collected pollen pellets. However, the latter display several disadvantages since they may contain pollutants, pathogens, or toxic phytochemicals. Consequently, companies have developed pollen-free artificial diets to sustain colonies. Such diets are designed to boost worker health in the field, in complement of floral pollen collected by workers outside the colonies, but their suitability in 'closed' systems without access to floral pollen, such as in laboratory bioassays, is arguable. Here, we used microcolonies of the commercially important bumble bee Bombus terrestris L. (Hymenoptera: Apidae) to assess the suitability of five artificial pollen substitutes and three mixed diets. We also assessed the evaporation rate of the different diets as it could impact their suitability. At the end of the bioassays, microcolonies fed the artificial diets showed a reduced offspring development when compared to microcolonies fed natural pollen, which was partly offset by mixing these diets with natural pollen. By contrast, the artificial diets did not have deleterious effects on worker's health. We discuss the potential nutritional and physical causes of artificial diets unsuitability for offspring development and encourage further research to accordingly establish appropriate pollen-free diets for bumble bee breeding.
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Affiliation(s)
- Antoine Gekière
- Laboratory de Zoology, Research institute for Biosciences, University of Mons, Mons, Belgium
| | - Denis Michez
- Laboratory de Zoology, Research institute for Biosciences, University of Mons, Mons, Belgium
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Fenner ED, Scapini T, da Costa Diniz M, Giehl A, Treichel H, Álvarez-Pérez S, Alves SL. Nature's Most Fruitful Threesome: The Relationship between Yeasts, Insects, and Angiosperms. J Fungi (Basel) 2022; 8:984. [PMID: 36294549 PMCID: PMC9605484 DOI: 10.3390/jof8100984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/13/2022] [Accepted: 09/18/2022] [Indexed: 07/30/2023] Open
Abstract
The importance of insects for angiosperm pollination is widely recognized. In fact, approximately 90% of all plant species benefit from animal-mediated pollination. However, only recently, a third part player in this story has been properly acknowledged. Microorganisms inhabiting floral nectar, among which yeasts have a prominent role, can ferment glucose, fructose, sucrose, and/or other carbon sources in this habitat. As a result of their metabolism, nectar yeasts produce diverse volatile organic compounds (VOCs) and other valuable metabolites. Notably, some VOCs of yeast origin can influence insects' foraging behavior, e.g., by attracting them to flowers (although repelling effects have also been reported). Moreover, when insects feed on nectar, they also ingest yeast cells, which provide them with nutrients and protect them from pathogenic microorganisms. In return, insects serve yeasts as transportation and a safer habitat during winter when floral nectar is absent. From the plant's point of view, the result is flowers being pollinated. From humanity's perspective, this ecological relationship may also be highly profitable. Therefore, prospecting nectar-inhabiting yeasts for VOC production is of major biotechnological interest. Substances such as acetaldehyde, ethyl acetate, ethyl butyrate, and isobutanol have been reported in yeast volatomes, and they account for a global market of approximately USD 15 billion. In this scenario, the present review addresses the ecological, environmental, and biotechnological outlooks of this three-party mutualism, aiming to encourage researchers worldwide to dig into this field.
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Affiliation(s)
- Eduardo D. Fenner
- Graduate Program in Environment and Sustainable Technologies, Federal University of Fronteira Sul, Campus Cerro Largo, Cerro Largo 97900-000, RS, Brazil
- Laboratory of Yeast Biochemistry, Federal University of Fronteira Sul, Campus Chapecó, Chapecó 89815-899, SC, Brazil
| | - Thamarys Scapini
- Laboratory of Microbiology and Bioprocesses, Federal University of Fronteira Sul, Campus Erechim, Erechim 99700-970, RS, Brazil
| | - Mariana da Costa Diniz
- Laboratory of Yeast Biochemistry, Federal University of Fronteira Sul, Campus Chapecó, Chapecó 89815-899, SC, Brazil
| | - Anderson Giehl
- Laboratory of Yeast Biochemistry, Federal University of Fronteira Sul, Campus Chapecó, Chapecó 89815-899, SC, Brazil
| | - Helen Treichel
- Laboratory of Microbiology and Bioprocesses, Federal University of Fronteira Sul, Campus Erechim, Erechim 99700-970, RS, Brazil
| | - Sergio Álvarez-Pérez
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain
| | - Sérgio L. Alves
- Graduate Program in Environment and Sustainable Technologies, Federal University of Fronteira Sul, Campus Cerro Largo, Cerro Largo 97900-000, RS, Brazil
- Laboratory of Yeast Biochemistry, Federal University of Fronteira Sul, Campus Chapecó, Chapecó 89815-899, SC, Brazil
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Feng YX, Lu XX, Du YS, Zhang JW, Almaz B, Zeng D, Du SS. Synergized potential, insecticidal and repellent activity of essential oils from two Rhododendron species against three stored product insects. JOURNAL OF ESSENTIAL OIL RESEARCH 2022. [DOI: 10.1080/10412905.2022.2118879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Yi-Xi Feng
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Xin-Xin Lu
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yue-Shen Du
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Jia-Wei Zhang
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Borjigidai Almaz
- Laboratory of Ethnomedicine, School of Pharmacy, Minzu University of China, Beijing, China
| | - Ding Zeng
- Department of Burns and Plastic Surgery, PLA Rocket Force Characteristic Medical Center, Beijing, China
| | - Shu-Shan Du
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
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34
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Morales-Poole JR, de Vega C, Tsuji K, Jacquemyn H, Junker RR, Herrera CM, Michiels C, Lievens B, Álvarez-Pérez S. Sugar Concentration, Nitrogen Availability, and Phylogenetic Factors Determine the Ability of Acinetobacter spp. and Rosenbergiella spp. to Grow in Floral Nectar. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02088-4. [PMID: 35930073 DOI: 10.1007/s00248-022-02088-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
The floral nectar of angiosperms harbors a variety of microorganisms that depend predominantly on animal visitors for their dispersal. Although some members of the genus Acinetobacter and all currently known species of Rosenbergiella are thought to be adapted to thrive in nectar, there is limited information about the response of these bacteria to variation in the chemical characteristics of floral nectar. We investigated the growth performance of a diverse collection of Acinetobacter (n = 43) and Rosenbergiella (n = 45) isolates obtained from floral nectar and the digestive tract of flower-visiting bees in a set of 12 artificial nectars differing in sugar content (15% w/v or 50% w/v), nitrogen content (3.48/1.67 ppm or 348/167 ppm of total nitrogen/amino nitrogen), and sugar composition (only sucrose, 1/3 sucrose + 1/3 glucose + 1/3 fructose, or 1/2 glucose + 1/2 fructose). Growth was only observed in four of the 12 artificial nectars. Those containing elevated sugar concentration (50% w/v) and low nitrogen content (3.48/1.67 ppm) were limiting for bacterial growth. Furthermore, phylogenetic analyses revealed that the ability of the bacteria to grow in different types of nectar is highly conserved between closely related isolates and genotypes, but this conservatism rapidly vanishes deeper in phylogeny. Overall, these results demonstrate that the ability of Acinetobacter spp. and Rosenbergiella spp. to grow in floral nectar largely depends on nectar chemistry and bacterial phylogeny.
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Affiliation(s)
- José R Morales-Poole
- Department of Animal Health, Complutense University of Madrid, 28040, Madrid, Spain
| | - Clara de Vega
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, 41012, Seville, Spain
| | - Kaoru Tsuji
- Department of Biology, Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan
| | - Hans Jacquemyn
- Laboratory of Plant Conservation and Population Biology, Biology Department, KU Leuven, B-3001, Heverlee, Belgium
| | - Robert R Junker
- Evolutionary Ecology of Plants, Department of Biology, Philipps-University Marburg, 35043, Marburg, Germany
- Department of Biosciences, University Salzburg, 5020, Salzburg, Austria
| | | | - Chris Michiels
- Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, KU Leuven, B-3001, Heverlee, Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems, KU Leuven, B-3001, Heverlee, Belgium
| | - Sergio Álvarez-Pérez
- Department of Animal Health, Complutense University of Madrid, 28040, Madrid, Spain.
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems, KU Leuven, B-3001, Heverlee, Belgium.
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35
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The impact of mass-flowering crops on bee pathogen dynamics. Int J Parasitol Parasites Wildl 2022; 18:135-147. [PMID: 35586790 PMCID: PMC9108762 DOI: 10.1016/j.ijppaw.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 04/29/2022] [Accepted: 05/01/2022] [Indexed: 11/24/2022]
Abstract
Nearly two fifths of the Earth's land area is currently used for agriculture, substantially impacting the environment and ecosystems. Besides the direct impact through land use change, intensive agriculture can also have an indirect impact, for example by changing wildlife epidemiology. We review here the potential effects of mass-flowering crops (MFCs), which are rapidly expanding in global cropping area, on the epidemiology of known pathogens in bee pollinators. We bring together the fifty MFCs with largest global area harvested and give an overview of their pollination dependency as well as their impact on bee pollinators. When in bloom these crops provide an abundance of flowers, which can provide nutrition for bees and increase bee reproduction. After their short bloom peak, however, the fields turn into green deserts. These big changes in floral availability strongly affect the plant-pollinator network, which in turn affects the pathogen transmission network, mediated by shared flowers. We address this dual role of flowers provided by MFCs, serving as nutritional resources as well as pathogen transmission spots, and bring together the current knowledge to assess how MFCs could affect pathogen prevalence in bee pollinator communities. MFC can greatly differ in nutritional quality and availability for bees. MFC can alter the pathogen transmission network of bees. MFC can abruptly alter the nutritional landscape during bloom and after.
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36
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Jiménez Elvira N, Ushio M, Sakai S. Are microbes growing on flowers evil? Effects of old flower microbes on fruit set in a wild ginger with one-day flowers, Alpinia japonica (Zingiberaceae). METABARCODING AND METAGENOMICS 2022. [DOI: 10.3897/mbmg.6.84331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Flowers are colonized and inhabited by diverse microbes. Flowers have various mechanisms to suppress microbial growth, such as flower volatiles, reactive oxygen and secondary compounds. Besides, plants rapidly replace flowers that have a short lifespan, and old flowers senesce. They may contribute to avoiding adverse effects of the microbes. In this study, we investigate if the flower microbial community on old flowers impedes fruit and seed production in a wild ginger with one-day flowers. We focus on microbes on old flowers because they may be composed of microbes that would grow during flowering if the flowers did not have mechanisms to suppress microbial growth. We inoculated newly opened flowers with old flower microbes, and monitored the effects on fruit and seed set. We also assessed prokaryotic communities on the flowers using 16S rRNA amplicon sequencing. We found six bacterial amplicon sequence variants (ASVs) whose proportions were increased on the inoculated flowers. These ASVs were also found on flower buds and flowers that were bagged by net or paper during anthesis, suggesting that they had been present in small numbers prior to flowering. Fruit set was negatively associated with the proportions of these ASVs, while seed set was not. The results suggest that old flowers harbor microbial communities different from those at anthesis, and that the microbes abundant on old flowers negatively affect plant reproduction. Although it has received little attention, antagonistic microbes that rapidly proliferate on the flowers may have affected the evolution of various flower characteristics such as flower volatiles and life span.
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37
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Stevenson PC, Koch H, Nicolson SW, Brown MJF. Natural processes influencing pollinator health. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210154. [PMID: 35491596 PMCID: PMC9062705 DOI: 10.1098/rstb.2021.0154] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Evidence from the last few decades indicates that pollinator abundance and diversity are at risk, with many species in decline. Anthropogenic impacts have been the focus of much recent work on the causes of these declines. However, natural processes, from plant chemistry, nutrition and microbial associations to landscape and habitat change, can also profoundly influence pollinator health. Here, we argue that these natural processes require greater attention and may even provide solutions to the deteriorating outlook for pollinators. Existing studies also focus on the decline of individuals and colonies and only occasionally at population levels. In the light of this we redefine pollinator health and argue that a top-down approach is required focusing at the ecological level of communities. We use examples from the primary research, opinion and review articles published in this special issue to illustrate how natural processes influence pollinator health, from community to individuals, and highlight where some of these processes could mitigate the challenges of anthropogenic and natural drivers of change. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Kent ME4 4TB, UK
| | - Hauke Koch
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK
| | - Susan W Nicolson
- Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa
| | - Mark J F Brown
- Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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38
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Egan PA, Stevenson PC, Stout JC. Pollinator selection against toxic nectar as a key facilitator of a plant invasion. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210168. [PMID: 35491597 DOI: 10.1098/rstb.2021.0168] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant compounds associated with herbivore defence occur widely in floral nectar and can impact pollinator health. We showed previously that Rhododendron ponticum nectar contains grayanotoxin I (GTX I) at concentrations that are lethal or sublethal to honeybees and a solitary bee in the plant's non-native range in Ireland. Here we further examined this conflict and tested the hypotheses that nectar GTX I is subject to negative pollinator-mediated selection in the non-native range, but that phenotypic linkage between GTX I levels in nectar and leaves acts as a constraint on independent evolution. We found that nectar GTX I experienced negative directional selection in the non-native range, in contrast to the native Iberian range, and that the magnitude and frequency of pollinator limitation indicated that selection was pollinator-mediated. Surprisingly, nectar GTX I levels were decoupled from those of leaves in the non-native range, which may have assisted post-invasion evolution of nectar without compromising the anti-herbivore function of GTX I (here demonstrated in bioassays with an ecologically relevant herbivore). Our study emphasizes the centrality of pollinator health as a concept linked to the invasion process, and how post-invasion evolution can be targeted toward minimizing lethal or sub-lethal effects on pollinators. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Paul A Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, Alnarp 23053, Sweden
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Jane C Stout
- Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
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39
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Nicolson SW. Sweet solutions: nectar chemistry and quality. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210163. [PMID: 35491604 PMCID: PMC9058545 DOI: 10.1098/rstb.2021.0163] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/07/2021] [Indexed: 12/22/2022] Open
Abstract
Nectar, the main floral reward for pollinators, varies greatly in composition and concentration. The assumption that nectar quality is equivalent to its sugar (energy) concentration is too simple. Diverse non-sugar components, especially amino acids and secondary metabolites, play various roles in nutrition and health of pollinators. Many nectar compounds have indirect effects by altering the foraging behaviour of pollinators or protecting them from disease. This review also emphasizes the water component of nectar, often ignored because of evaporative losses and difficulties in sampling small nectar volumes. Nectar properties vary with environmental factors, pollinator visits and microbial contamination. Pollination mutualisms depend on the ability of insect and vertebrate pollinators to cope with and benefit from the variation and diversity in nectar chemistry. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Susan W. Nicolson
- Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
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40
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Fowler AE, Sadd BM, Bassingthwaite T, Irwin RE, Adler LS. Consuming sunflower pollen reduced pathogen infection but did not alter measures of immunity in bumblebees. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210160. [PMID: 35491606 DOI: 10.1098/rstb.2021.0160] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Certain diets can benefit bee health by reducing pathogens, but the mechanism(s) driving these medicinal effects are largely unexplored. Recent research found that sunflower (Helianthus annuus) pollen reduces the gut pathogen Crithidia bombi in the common eastern bumblebee (Bombus impatiens). Here, we tested the effects of sunflower pollen and infection on two bee immune metrics to determine whether sunflower pollen diet drives changes in host immunity that can explain this medicinal effect. Bees were infected with C. bombi or not and given either sunflower or wildflower pollen. Subsequently, bees received a benign immune challenge or were left naive to test the induced and constitutive immune responses, respectively. We measured haemolymph phenoloxidase activity, involved in the melanization cascade, and antibacterial activity. Sunflower pollen reduced C. bombi infection, but we found no significant pollen diet effect on either immune measure. Phenoloxidase activity was also not affected by C. bombi infection status; however, uninfected bees were more likely to have measurable constitutive antibacterial activity, while infected bees had higher induced antibacterial activity. Overall, we found that sunflower pollen does not significantly affect the immune responses we measured, suggesting that the mechanisms underlying its medicinal effect do not involve these bee immune parameters. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Alison E Fowler
- Department of Biology, University of Massachusetts Amherst, 221 Morrill Science Center South, 611 North Pleasant Street, Amherst, MA 01003, USA
| | - Ben M Sadd
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Toby Bassingthwaite
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA
| | - Lynn S Adler
- Department of Biology, University of Massachusetts Amherst, 221 Morrill Science Center South, 611 North Pleasant Street, Amherst, MA 01003, USA
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41
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Béchade B, Hu Y, Sanders JG, Cabuslay CS, Łukasik P, Williams BR, Fiers VJ, Lu R, Wertz JT, Russell JA. Turtle ants harbor metabolically versatile microbiomes with conserved functions across development and phylogeny. FEMS Microbiol Ecol 2022; 98:6602351. [PMID: 35660864 DOI: 10.1093/femsec/fiac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/16/2022] [Accepted: 06/01/2022] [Indexed: 11/14/2022] Open
Abstract
Gut bacterial symbionts can support animal nutrition by facilitating digestion and providing valuable metabolites. However, changes in symbiotic roles between immature and adult stages are not well documented, especially in ants. Here, we explored the metabolic capabilities of microbiomes sampled from herbivorous turtle ant (Cephalotes sp.) larvae and adult workers through (meta)genomic screening and in vitro metabolic assays. We reveal that larval guts harbor bacterial symbionts with impressive metabolic capabilities, including catabolism of plant and fungal recalcitrant dietary fibers and energy-generating fermentation. Additionally, several members of the specialized adult gut microbiome, sampled downstream of an anatomical barrier that dams large food particles, show a conserved potential to depolymerize many dietary fibers. Symbionts from both life stages have the genomic capacity to recycle nitrogen and synthesize amino acids and B-vitamins. With help of their gut symbionts, including several bacteria likely acquired from the environment, turtle ant larvae may aid colony digestion and contribute to colony-wide nitrogen, B-vitamin and energy budgets. In addition, the conserved nature of the digestive capacities among adult-associated symbionts suggests that nutritional ecology of turtle ant colonies has long been shaped by specialized, behaviorally-transferred gut bacteria with over 45 million years of residency.
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Affiliation(s)
- Benoît Béchade
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Yi Hu
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America.,State Key Laboratory of Earth Surface Processes and Resource Ecology and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Jon G Sanders
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Christian S Cabuslay
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Piotr Łukasik
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
| | - Bethany R Williams
- Department of Biology, Calvin College, Grand Rapids, Michigan, United States of America
| | - Valerie J Fiers
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Richard Lu
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - John T Wertz
- Department of Biology, Calvin College, Grand Rapids, Michigan, United States of America
| | - Jacob A Russell
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America
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42
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McPeek SJ, Bronstein JL, McPeek MA. Eco-evolutionary feedbacks among pollinators, herbivores, and their plant resources. Evolution 2022; 76:1287-1300. [PMID: 35420697 PMCID: PMC9321553 DOI: 10.1111/evo.14492] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/19/2022] [Accepted: 03/23/2022] [Indexed: 01/21/2023]
Abstract
Eco-evolutionary feedbacks among multiple species occur when one species affects another species' evolution via its effects on the abundance and traits of a shared partner species. What happens if those two species enact opposing effects on their shared partner's population growth? Furthermore, what if those two kinds of interactions involve separate traits? For example, many plants produce distinct suites of traits that attract pollinators (mutualists) and deter herbivores (antagonists). Here, we develop a model to explore how pollinators and herbivores may influence each other's interactions with a shared plant species via evolutionary effects on the plant's nectar and toxin traits. The model results predict that herbivores indirectly select for the evolution of increased nectar production by suppressing plant population growth. The model also predicts that pollinators indirectly select for the evolution of increased toxin production by plants and increased counterdefenses by herbivores via their positive effects on plant population growth. Unless toxins directly affect pollinator foraging, plants always evolve increases in attraction and defense traits when they interact with both kinds of foragers. This work highlights the value of incorporating ecological dynamics to understand the entangled evolution of mutualisms and antagonisms in natural communities.
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Affiliation(s)
- Sarah J. McPeek
- Department of BiologyUniversity of VirginiaCharlottesvilleVA22904USA
| | - Judith L. Bronstein
- Department of Ecology & Evolutionary BiologyUniversity of ArizonaTucsonAZ85721USA
| | - Mark A. McPeek
- Department of Biological SciencesDartmouth CollegeHanoverNH03755USA
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43
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Peters B, Keller A, Leonhardt SD. Diets maintained in a changing world: Does land‐use intensification alter wild bee communities by selecting for flexible generalists? Ecol Evol 2022; 12:e8919. [PMID: 35600696 PMCID: PMC9108308 DOI: 10.1002/ece3.8919] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 04/07/2022] [Accepted: 04/19/2022] [Indexed: 11/08/2022] Open
Affiliation(s)
- Birte Peters
- Department for Animal Ecology and Tropical Biology University of Würzburg Biocenter Würzburg Germany
- Department of Bioinformatics University of Würzburg Biocenter Würzburg Germany
- Center for Computational and Theoretical Biology University of Würzburg Würzburg Germany
| | - Alexander Keller
- Cellular and Organismic Networks Faculty of Biology Ludwig‐Maximilians‐Universität Munich Planegg‐Martinsried Germany
| | - Sara Diana Leonhardt
- Department for Animal Ecology and Tropical Biology University of Würzburg Biocenter Würzburg Germany
- Department of Life Science Systems Technical University of Munich Freising Germany
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44
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Filipiak ZM, Denisow B, Stawiarz E, Filipiak M. Unravelling the dependence of a wild bee on floral diversity and composition using a feeding experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153326. [PMID: 35074369 DOI: 10.1016/j.scitotenv.2022.153326] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
We investigated nutrition as a potential mechanism underlying the link between floral diversity/composition and wild bee performance. The health, resilience, and fitness of bees may be limited by a lack of nutritionally balanced larval food (pollen), influencing the entire population, even if adults are not limited nutritionally by the availability and quality of their food (mainly nectar). We hypothesized that the nutritional quality of bee larval food is indirectly connected to the species diversity of pollen provisions and is directly driven by the pollen species composition. Therefore, the accessibility of specific, nutritionally desirable key plant species for larvae might promote bee populations. Using a fully controlled feeding experiment, we simulated different pollen resources that could be available to bees in various environments, reflecting potential changes in floral species diversity and composition that could be caused by landscape changes. Suboptimal concentrations of certain nutrients in pollen produced by specific plant species resulted in reduced bee fitness. The negative effects were alleviated when scarce nutrients were added to these pollen diets. The scarcity of specific nutrients was associated with certain plant species but not with plant diversity. Thus, one of the mechanisms underlying the decreased fitness of wild bees in homogenous landscapes may be nutritional imbalance, i.e., the scarcity of specific nutrients associated with the presence of certain plant species and not with species diversity in pollen provisions eaten by larvae. Accordingly, we provide a conceptual representation of how the floral species composition and diversity can impact bee populations by affecting fitness-related life history traits. Additionally, we suggest that mixes of 'bee-friendly' plants used to improve the nutritional base for wild bees should be composed considering the local flora to supplement bees with vital nutrients that are scarce in the considered environment.
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Affiliation(s)
- Zuzanna M Filipiak
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland
| | - Bożena Denisow
- Laboratory of Plant Biology, Department of Botany and Plant Physiology, University of Life Sciences in Lublin, Lublin, Poland.
| | - Ernest Stawiarz
- Laboratory of Plant Biology, Department of Botany and Plant Physiology, University of Life Sciences in Lublin, Lublin, Poland.
| | - Michał Filipiak
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, Poland.
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45
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Fitch G, Figueroa LL, Koch H, Stevenson PC, Adler LS. Understanding effects of floral products on bee parasites: Mechanisms, synergism, and ecological complexity. Int J Parasitol Parasites Wildl 2022; 17:244-256. [PMID: 35299588 PMCID: PMC8920997 DOI: 10.1016/j.ijppaw.2022.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 12/27/2022]
Abstract
Floral nectar and pollen commonly contain diverse secondary metabolites. While these compounds are classically thought to play a role in plant defense, recent research indicates that they may also reduce disease in pollinators. Given that parasites have been implicated in ongoing bee declines, this discovery has spurred interest in the potential for 'medicinal' floral products to aid in pollinator conservation efforts. We review the evidence for antiparasitic effects of floral products on bee diseases, emphasizing the importance of investigating the mechanism underlying antiparasitic effects, including direct or host-mediated effects. We discuss the high specificity of antiparasitic effects of even very similar compounds, and highlight the need to consider how nonadditive effects of multiple compounds, and the post-ingestion transformation of metabolites, mediate the disease-reducing capacity of floral products. While the bulk of research on antiparasitic effects of floral products on bee parasites has been conducted in the lab, we review evidence for the impact of such effects in the field, and highlight areas for future research at the floral product-bee disease interface. Such research has great potential both to enhance our understanding of the role of parasites in shaping plant-bee interactions, and the role of plants in determining bee-parasite dynamics. This understanding may in turn reveal new avenues for pollinator conservation.
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Affiliation(s)
- Gordon Fitch
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
- Corresponding author.
| | - Laura L. Figueroa
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Hauke Koch
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE, UK
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE, UK
- Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
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46
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Gekière A, Semay I, Gérard M, Michez D, Gerbaux P, Vanderplanck M. Poison or Potion: Effects of Sunflower Phenolamides on Bumble Bees and Their Gut Parasite. BIOLOGY 2022; 11:biology11040545. [PMID: 35453744 PMCID: PMC9030180 DOI: 10.3390/biology11040545] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 11/29/2022]
Abstract
Simple Summary Bee declines have been reported worldwide, partly due to parasite spread induced by human activities. However, bees may forage on specific floral resources to face parasite infection. Such natural resources are comparable to ‘natural pharmacies’ and may be favoured in bee conservation strategies. Consumption of sunflower pollen, despite being detrimental for larval development, has been recently shown to reduce the load of a widespread bumble bee gut parasite in the common eastern bumble bee. Although the underlying mechanisms remain unknown, it has been suggested that sunflower phenolamides—a family of molecules found in most flowering plants—may be responsible for such a reduction in parasite load. Here, we tested the impacts of sunflower phenolamides on healthy and infected buff-tailed bumble bees. Expectedly, sunflower pollen had harmful consequences on bumble bee development but surprisingly, it did not alter parasite load. By contrast, sunflower phenolamides had milder effects on bumble bee development but unexpectedly increased parasite load. Phenolamide effects may stem from the physiological stress they induced or the gut microbial community alteration they may have triggered. Since biological models and experimental framework differ greatly in related studies tackling plant–bee–parasite interplays, we challenged the definition of medicinal effects and questioned the way to assess them in controlled conditions. Abstract Specific floral resources may help bees to face environmental challenges such as parasite infection, as recently shown for sunflower pollen. Whereas this pollen diet is known to be unsuitable for the larval development of bumble bees, it has been shown to reduce the load of a trypanosomatid parasite (Crithidia bombi) in the bumble bee gut. Recent studies suggested it could be due to phenolamides, a group of compounds commonly found in flowering plants. We, therefore, decided to assess separately the impacts of sunflower pollen and its phenolamides on a bumble bee and its gut parasite. We fed Crithidia-infected and -uninfected microcolonies of Bombus terrestris either with a diet of willow pollen (control), a diet of sunflower pollen (natural diet) or a diet of willow pollen supplemented with sunflower phenolamides (supplemented diet). We measured several parameters at both microcolony (i.e., food collection, parasite load, brood development and stress responses) and individual (i.e., fat body content and phenotypic variation) levels. As expected, the natural diet had detrimental effects on bumble bees but surprisingly, we did not observe any reduction in parasite load, probably because of bee species-specific outcomes. The supplemented diet also induced detrimental effects but by contrast to our a priori hypothesis, it led to an increase in parasite load in infected microcolonies. We hypothesised that it could be due to physiological distress or gut microbiota alteration induced by phenolamide bioactivities. We further challenged the definition of medicinal effects and questioned the way to assess them in controlled conditions, underlining the necessity to clearly define the experimental framework in this research field.
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Affiliation(s)
- Antoine Gekière
- Laboratoire de Zoologie, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium;
- Correspondence: (A.G.); (M.V.); Tel.: +32-65373436 (A.G.)
| | - Irène Semay
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium; (I.S.); (P.G.)
| | - Maxence Gérard
- Insect Lab., Division of Functional Morphology, Department of Zoology, Stockholm University, 11418 Stockholm, Sweden;
| | - Denis Michez
- Laboratoire de Zoologie, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium;
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium; (I.S.); (P.G.)
| | - Maryse Vanderplanck
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 34293 Montpellier, France
- Correspondence: (A.G.); (M.V.); Tel.: +32-65373436 (A.G.)
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Palmer-Young EC, Schwarz RS, Chen Y, Evans JD. Punch in the gut: Parasite tolerance of phytochemicals reflects host diet. Environ Microbiol 2022; 24:1805-1817. [PMID: 35315572 DOI: 10.1111/1462-2920.15981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/18/2022] [Accepted: 03/20/2022] [Indexed: 11/30/2022]
Abstract
Gut parasites of plant-eating insects are exposed to antimicrobial phytochemicals that can reduce infection. Trypanosomatid gut parasites infect insects of diverse nutritional ecologies as well as mammals and plants, raising the question of how host diet-associated phytochemicals shape parasite evolution and host specificity. To test the hypothesis that phytochemical tolerance of trypanosomatids reflects the chemical ecology of their hosts, we compared related parasites from honey bees and mosquitoes-hosts that differ in phytochemical consumption-and contrasted our results with previous studies on phylogenetically related, human-parasitic Leishmania. We identified one bacterial and ten plant-derived substances with known antileishmanial activity that also inhibited honey bee parasites associated with colony collapse. Bee parasites exhibited greater tolerance of chrysin-a flavonoid found in nectar, pollen, and plant resin-derived propolis. In contrast, mosquito parasites were more tolerant of cinnamic acid-a product of lignin decomposition present in woody debris-rich larval habitats. Parasites from both hosts tolerated many compounds that inhibit Leishmania, hinting at possible trade-offs between phytochemical tolerance and mammalian infection. Our results implicate the phytochemistry of host diets as a potential driver of insect-trypanosomatid associations, and identify compounds that could be incorporated into colony diets or floral landscapes to ameliorate infection in bees. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | - Ryan S Schwarz
- Department of Biology, Fort Lewis College, Durango, CO, USA
| | | | - Jay D Evans
- USDA-ARS Bee Research Lab, Beltsville, MD, USA
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Rusman Q, Hooiveld‐Knoppers S, Dijksterhuis M, Bloem J, Reichelt M, Dicke M, Poelman EH. Flowers prepare thyselves: leaf and root herbivores induce specific changes in floral phytochemistry with consequences for plant interactions with florivores. THE NEW PHYTOLOGIST 2022; 233:2548-2560. [PMID: 34953172 PMCID: PMC9305281 DOI: 10.1111/nph.17931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
The phenotypic plasticity of flowering plants in response to herbivore damage to vegetative tissues can affect plant interactions with flower-feeding organisms. Such induced systemic responses are probably regulated by defence-related phytohormones that signal flowers to alter secondary chemistry that affects resistance to florivores. Current knowledge on the effects of damage to vegetative tissues on plant interactions with florivores and the underlying mechanisms is limited. We compared the preference and performance of two florivores on flowering Brassica nigra plants damaged by one of three herbivores feeding from roots or leaves. To investigate the underlying mechanisms, we quantified expression patterns of marker genes for defence-related phytohormonal pathways, and concentrations of phytohormones and glucosinolates in buds and flowers. Florivores displayed contrasting preferences for plants damaged by herbivores feeding on roots and leaves. Chewing florivores performed better on plants damaged by folivores, but worse on plants damaged by the root herbivore. Chewing root and foliar herbivory led to specific induced changes in the phytohormone profile of buds and flowers. This resulted in increased glucosinolate concentrations for leaf-damaged plants, and decreased glucosinolate concentrations for root-damaged plants. The outcome of herbivore-herbivore interactions spanning from vegetative tissues to floral tissues is unique for the inducing root/leaf herbivore and receiving florivore combination.
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Affiliation(s)
- Quint Rusman
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
- Present address:
Department of Systematic and Evolutionary BotanyUniversity of ZürichZollikerstrasse 1078008ZürichSwitzerland
| | - Sanne Hooiveld‐Knoppers
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
| | - Mirjam Dijksterhuis
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
| | - Janneke Bloem
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
| | - Michael Reichelt
- Department of BiochemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Strasse 807745JenaGermany
| | - Marcel Dicke
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
| | - Erik H. Poelman
- Laboratory of EntomologyWageningen University & ResearchDroevendaalsesteeg 1Wageningen6708PBthe Netherlands
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Richman SK, Maalouf IM, Smilanich AM, Marquez Sanchez D, Miller SZ, Leonard AS. A neonicotinoid pesticide alters how nectar chemistry affects bees. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Sharron Z. Miller
- Department of Biology University of Nevada Reno NV 89557 USA
- Department of Entomology Michigan State University Lansing MI 48864 USA
| | - Anne S. Leonard
- Department of Biology University of Nevada Reno NV 89557 USA
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50
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Giacomini JJ, Moore N, Adler LS, Irwin RE. Sunflower pollen induces rapid excretion in bumble bees: Implications for host-pathogen interactions. JOURNAL OF INSECT PHYSIOLOGY 2022; 137:104356. [PMID: 35016876 DOI: 10.1016/j.jinsphys.2022.104356] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/08/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Host diet can have a profound effect on host-pathogen interactions, including indirect effects on pathogens mediated through host physiology. In bumble bees (Bombus impatiens), the consumption of sunflower (Helianthus annuus) pollen dramatically reduces infection by the gut protozoan pathogen Crithidia bombi. One hypothesis for the medicinal effect of sunflower pollen is that consumption changes host gut physiological function, causing rapid excretion that flushes C. bombi from the system. We tested the effect of pollen diet and C. bombi infection on gut transit properties using a 2x2 factorial experiment in which bees were infected with C. bombi or not and fed sunflower or wildflower pollen diet. We measured several non-mutually exclusive physiological processes that underlie the insect excretory system, including gut transit time, bi-hourly excretion rate, the total number of excretion events and the total volume of excrement. Sunflower pollen significantly reduced gut transit time in uninfected bees, and increased the total number of excretion events and volume of excrement by 66 % and 68 %, respectively, in both infected and uninfected bees. Here we show that a sunflower pollen diet can affect host physiology gut function, causing more rapid and greater excretion. These results provide important insight into a mechanism that could underlie the medicinal effect of sunflower pollen for bumble bees.
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Affiliation(s)
- Jonathan J Giacomini
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695 USA.
| | - Nicholas Moore
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695 USA
| | - Lynn S Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003 USA
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695 USA
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