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Fortier CE, Musso AE, Evenden ML, Zaharia LI, Cooke JEK. Evidence that Ophiostomatoid Fungal Symbionts of Mountain Pine Beetle Do Not Play a Role in Overcoming Lodgepole Pine Defenses During Mass Attack. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:445-458. [PMID: 38240660 DOI: 10.1094/mpmi-06-23-0077-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a devastating forest insect pest that has killed millions of hectares of pines in western North America over the past two decades. Like other bark beetles, MPB vectors ophiostomatoid fungal species, some of which are pathogenic to host pine species. The phytopathogenicity of these fungal symbionts has sparked considerable debate regarding their role in facilitating MPB attack success. We tested the hypothesis that MPB ophiostomatoid fungal associates like Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield contribute to overwhelming host defenses during MPB mass attack. We compared responses of mature lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees growing in natural stands that were mass attacked by MPB with those inoculated with G. clavigera by examining host defense hormones, secondary metabolites, and gene expression profiles. The jasmonate and ethylene signatures of necrotrophic pathogen-triggered response were identified in G. clavigera-inoculated trees, but only the jasmonate signature of a herbivore-triggered response was measured in MPB-attacked trees. Several G. clavigera-induced changes in pine phenolic metabolite profiles and phenolic biosynthesis gene expression patterns were absent in MPB-attacked pines. These findings indicate that ophiostomatoid fungi like G. clavigera are not a major factor in overwhelming host defenses during MPB mass attack. Instead, fungal pathogenicity likely is more important in aiding MPB colonization and development within the host tree. Phenolics appear to play a larger role in the host response to G. clavigera than to MPB, although phenolics may also influence MPB feeding and behavior. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Colleen E Fortier
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Antonia E Musso
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Maya L Evenden
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - L Irina Zaharia
- National Research Council of Canada, Aquatic and Crop Resource Development Research Centre, Saskatoon, SK, S7N 0W9, Canada
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
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Zaman R, May C, Ullah A, Erbilgin N. Bark Beetles Utilize Ophiostomatoid Fungi to Circumvent Host Tree Defenses. Metabolites 2023; 13:metabo13020239. [PMID: 36837858 PMCID: PMC9968207 DOI: 10.3390/metabo13020239] [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: 12/29/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Bark beetles maintain symbiotic associations with a diversity of microbial organisms, including ophiostomatoid fungi. Studies have frequently reported the role of ophiostomatoid fungi in bark beetle biology, but how fungal symbionts interact with host chemical defenses over time is needed. We first investigated how inoculations by three fungal symbionts of mountain pine beetle affect the terpene chemistry of live lodgepole pine trees. We then conducted a complimentary laboratory experiment specifically measuring the host metabolite degradation by fungi and collected the fungal organic volatiles following inoculations with the same fungal species on lodgepole pine logs. In both experiments, we analyzed the infected tissues for their terpene chemistry. Additionally, we conducted an olfactometer assay to determine whether adult beetles respond to the volatile organic chemicals emitted from each of the three fungal species. We found that all fungi upregulated terpenes as early as two weeks after inoculations. Similarly, oxygenated monoterpene concentrations also increased by several folds (only in logs). A large majority of beetles tested showed a strong attraction to two fungal species, whereas the other fungus repelled the beetles. Together this study shows that fungal symbionts can alter host defense chemistry, assist beetles in overcoming metabolite toxicity, and provide possible chemical cues for bark beetle attraction.
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Lee GYS, Wertman DL, Carroll AL, Hamelin RC. Filamentous fungal associates of the alder bark beetle, Alniphagus aspericollis, including an undescribed species of Neonectria. PLoS One 2023; 18:e0284393. [PMID: 37155652 PMCID: PMC10166519 DOI: 10.1371/journal.pone.0284393] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 03/29/2023] [Indexed: 05/10/2023] Open
Abstract
Bark beetles (Coleoptera: Curculionidae; Scolytinae) are tree-infesting insects that consume subcortical tissues and fungi. Species capable of killing their host trees are most commonly associated with conifers, as very few bark beetle species infest and kill hardwood hosts directly. The alder bark beetle, Alniphagus aspericollis, is a hardwood-killing bark beetle that colonizes and kills red alder, Alnus rubra. Conifer-killing bark beetles have well-known associations with symbiotic ophiostomatoid fungi that facilitate their life histories, but it is unknown whether A. aspericollis has any fungal associates. This study was conducted to identify any consistent filamentous fungal associates of A. aspericollis and characterize the consistency of observed beetle-fungus relationships. Beetles and gallery phloem samples were collected from seven sites throughout the Greater Vancouver region in British Columbia, Canada. Filamentous fungi were isolated from these samples and identified by DNA barcoding using the internal transcribed spacer (ITS) region and other barcode regions for resolution to the species-level for the most dominant isolates. The most common fungal associate was a previously undescribed Neonectria major-like fungus, Neonectria sp. nov., which was isolated from ~67% of adult beetles, ~59% of phloem samples, and ~94% of the beetle-infested trees. Ophiostoma quercus was isolated from ~28% of adult beetles, ~9% of phloem samples, and ~56% of infested trees and deemed a casual associate of A. aspericollis, while a putatively novel species of Ophiostoma was more infrequently isolated from A. aspericollis and its galleries. Cadophora spadicis, a new record for red alder, was rarely isolated and is probably coincidentally carried by A. aspericollis. Overall, A. aspericollis was only loosely associated with ophiostomatoid fungi, suggesting that these fungi have little ecological significance in the beetle-tree interaction, while Neonectria sp. nov. may be a symbiote of A. aspericollis that is vectored by the beetle.
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Affiliation(s)
- Gervais Y S Lee
- Department of Forest and Conservation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Debra L Wertman
- Department of Forest and Conservation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Allan L Carroll
- Department of Forest and Conservation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard C Hamelin
- Department of Forest and Conservation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
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Wu S, Wu J, Wang Y, Qu Y, He Y, Wang J, Cheng J, Zhang L, Cheng C. Discovery of entomopathogenic fungi across geographical regions in southern China on pine sawyer beetle Monochamus alternatus and implication for multi-pathogen vectoring potential of this beetle. FRONTIERS IN PLANT SCIENCE 2022; 13:1061520. [PMID: 36643293 PMCID: PMC9832029 DOI: 10.3389/fpls.2022.1061520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Entomopathogen-based biocontrol is crucial for blocking the transmission of vector-borne diseases; however, few cross-latitudinal investigations of entomopathogens have been reported for vectors transmitting woody plant diseases in forest ecosystems. The pine sawyer beetle Monochamus alternatus is an important wood borer and a major vector transmitting pine wilt disease, facilitating invasion of the pinewood nematode Bursaphelenchus xylophilus (PWN) in China. Due to the limited geographical breadth of sampling regions, species diversity of fungal associates (especially entomopathogenic fungi) on M. alternatus adults and their potential ecological functions have been markedly underestimated. In this study, through traditional fungal isolation with morphological and molecular identification, 640 fungal strains (affiliated with 15 genera and 39 species) were isolated from 81 beetle cadavers covered by mycelia or those symptomatically alive across five regional populations of this pest in southern China. Multivariate analyses revealed significant differences in the fungal community composition among geographical populations of M. alternatus, presenting regionalized characteristics, whereas no significant differences were found in fungal composition between beetle genders or among body positions. Four region-representative fungi, namely, Lecanicillium attenuatum (Zhejiang), Aspergillus austwickii (Sichuan), Scopulariopsis alboflavescens (Fujian), and A. ruber (Guangxi), as well as the three fungal species Beauveria bassiana, Penicillium citrinum, and Trichoderma dorotheae, showed significantly stronger entomopathogenic activities than other fungi. Additionally, insect-parasitic entomopathogenic fungi (A. austwickii, B. bassiana, L. attenuatum, and S. alboflavescens) exhibited less to no obvious phytopathogenic activities on the host pine Pinus massoniana, whereas P. citrinum, Purpureocillium lilacinum, and certain species of Fusarium spp.-isolated from M. alternatus body surfaces-exhibited remarkably higher phytopathogenicity. Our results provide a broader view of the entomopathogenic fungal community on the vector beetle M. alternatus, some of which are reported for the first time on Monochamus spp. in China. Moreover, this beetle might be more highly-risk in pine forests than previously considered, as a potential multi-pathogen vector of both PWN and phytopathogenic fungi.
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Affiliation(s)
- Shengxin Wu
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Jia Wu
- Station of Forest Pest Control, Anji Forestry Bureau, Huzhou, Zhejiang, China
| | - Yun Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Yifei Qu
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Yao He
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Jingyan Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Jianhui Cheng
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Liqin Zhang
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
| | - Chihang Cheng
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou, Zhejiang, China
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Agbulu V, Zaman R, Ishangulyyeva G, Cahill JF, Erbilgin N. Host Defense Metabolites Alter the Interactions between a Bark Beetle and its Symbiotic Fungi. MICROBIAL ECOLOGY 2022; 84:834-843. [PMID: 34674014 DOI: 10.1007/s00248-021-01894-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Successful host plant colonization by tree-killing bark beetle-symbiotic fungal complexes depends on host suitability, which is largely determined by host defense metabolites such as monoterpenes. Studies have shown the ability of specific blends of host monoterpenes to influence bark beetles or their fungal symbionts, but how biologically relevant blends of host monoterpenes influence bark beetle-symbiotic fungal interaction is unknown. We tested how interactions between two host species (lodgepole pine or jack pine) and two fungal symbionts of mountain pine beetle (Grosmannia clavigera or Ophiostoma montium) affect the performance of adult female beetles in vitro. Beetles treated with the propagules of G. clavigera or O. montium or not treated (natural fungal load) were introduced into media amended with a blend of the entire monoterpene profile of either host species and beetle performance was compared. Overall, host blends altered beetle performance depending on the fungal species used in the beetle amendment. When beetles were amended with G. clavigera, their performance was superior over beetles amended with O. montium in either host blend. Furthermore, G. clavigera-amended beetles performed better in media amended with host blends than without a host blend; in contrast, O. montium-amended beetles performed better in media without a host blend than with a host blend. Overall, this study showed that host defense metabolites affect host suitability to bark beetles through influencing their fungal symbionts and that different species of fungal symbionts respond differentlly to host defense metabolites.
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Affiliation(s)
- Vanessa Agbulu
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Rashaduz Zaman
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | | | - James F Cahill
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - N Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada.
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Diversity and Evolution of Entomocorticium (Russulales, Peniophoraceae), a Genus of Bark Beetle Mutualists Derived from Free-Living, Wood Rotting Peniophora. J Fungi (Basel) 2021; 7:jof7121043. [PMID: 34947025 PMCID: PMC8706356 DOI: 10.3390/jof7121043] [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: 10/21/2021] [Revised: 11/30/2021] [Accepted: 12/03/2021] [Indexed: 11/17/2022] Open
Abstract
Symbiosis between insects and fungi arose multiple times during the evolution of both groups, and some of the most biologically diverse and economically important are mutualisms in which the insects cultivate and feed on fungi. Among these are bark beetles, whose ascomycetous cultivars are better known and studied than their frequently-overlooked and poorly understood basidiomycetous partners. In this study, we propose five new species of Entomocorticium, fungal mutualists in the Russulales (Basidiomycota) that are mutualistic symbionts of scolytine beetles. We have isolated these fungi from the beetle mycangia, which are structures adapted for the selective storage and transportation of fungal mutualists. Herein, we present the most complete phylogeny of the closely related genera Entomocorticium and Peniophora and provide insights into how an insect-associated taxon (Entomocorticium) evolved from within a wood-decaying, wind-dispersed lineage (Peniophora). Our results indicate that following a transition from angiosperms to gymnosperms, fungal domestication by beetles facilitated the evolution and diversification of Entomocorticium. We additionally propose four new species: Entomocorticium fibulatum Araújo, Li & Hulcr, sp. nov.; E. belizense Araújo, Li & Hulcr, sp. nov.; E. perryae Araújo, Li & Hulcr, sp. nov.; and E. macrovesiculatum Araújo, Li, Six & Hulcr, sp. nov. Our findings highlight the fact that insect-fungi associations remain an understudied field and that these associations harbor a large reservoir of novel fungal species.
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Fungal associates of an invasive pine-infesting bark beetle, Dendroctonus valens, including seven new Ophiostomatalean fungi. Persoonia - Molecular Phylogeny and Evolution of Fungi 2021; 45:177-195. [PMID: 34456376 PMCID: PMC8375344 DOI: 10.3767/persoonia.2020.45.07] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/02/2020] [Indexed: 11/25/2022]
Abstract
The red turpentine beetle (RTB; Dendroctonus valens) is a bark beetle that is native to Central and North America. This insect is well-known to live in association with a large number of Ophiostomatalean fungi. The beetle is considered a minor pest in its native range, but has killed millions of indigenous pine trees in China after its appearance in that country in the late 1990s. In order to increase the base of knowledge regarding the RTB and its symbionts, surveys of the beetle's fungal associates were initially undertaken in China, and in a subsequent study in its native range in North America. A total of 30 Ophiostomatalean species that included several undescribed taxa, were identified in these surveys. In the present study, seven of the undescribed taxa collected during the surveys were further characterised based on their morphological characteristics and multi-gene phylogenies. We proceeded to describe five of these as novel Leptographium spp. and two as new species of Ophiostoma. Four of the Leptographium spp. resided in the G. galeiformis-species complex, while one formed part of the L. olivaceum-species complex. One Ophiostoma sp. was a member of the O. ips-species complex, while the only new species from China was closely related to O. floccosum. Two of the previously undescribed taxa from North America were shown to be congeneric with L. terebrantis, implying that this species was most often isolated in association with the RTB in North America. The undescribed taxon from North America was identified as O. ips, and like L. terebrantis, this species was also not recognized during the initial North American survey. Resolving the identities of these taxa provides essential baseline information to better understand the movement of fungal pathogens with this beetle. This then enhances our ability to accurately assess and predict the risks of invasions by these and related fungi.
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Fukasawa Y, Matsukura K, Stephan JG, Makoto K, Suzuki SN, Kominami Y, Takagi M, Tanaka N, Takemoto S, Kinuura H, Okano K, Song Z, Jomura M, Kadowaki K, Yamashita S, Ushio M. Patterns of community composition and diversity in latent fungi of living Quercus serrata trunks across a range of oak wilt prevalence and climate variables in Japan. FUNGAL ECOL 2021. [DOI: 10.1016/j.funeco.2021.101095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Stephan P, Bramon Mora B, Alexander JM. Positive species interactions shape species' range limits. OIKOS 2021. [DOI: 10.1111/oik.08146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Pauline Stephan
- Dept of Environmental Systems Science, ETH Zürich Zürich Switzerland
| | | | - Jake M. Alexander
- Dept of Environmental Systems Science, ETH Zürich Zürich Switzerland
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Guevara-Rozo S, Hussain A, Cale JA, Klutsch JG, Rajabzadeh R, Erbilgin N. Nitrogen and Ergosterol Concentrations Varied in Live Jack Pine Phloem Following Inoculations With Fungal Associates of Mountain Pine Beetle. Front Microbiol 2020; 11:1703. [PMID: 32793164 PMCID: PMC7390957 DOI: 10.3389/fmicb.2020.01703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/29/2020] [Indexed: 01/14/2023] Open
Abstract
Bark beetles form symbiotic associations with multiple species of fungi that supplement their metabolic needs. However, the relative contributions of each symbiont to the nutrition of bark beetles have been largely unexplored. Thus, we evaluated the ability of three fungal symbionts of mountain pine beetle to concentrate nitrogen and produce ergosterol while infecting phloem of a novel host jack pine. Ergosterol was used as proxy to determine the fungal biomass (hyphal density) in the current study. We inoculated 80 trees in two forest stands with one of the three fungal species or a non-fungal (control) agar. Six weeks later, we collected phloem from the necrotic lesions induced by the fungi, uninfected tissues adjacent to lesions, and non-inoculated control trees. We found that nutritional contributions varied with fungal species. Nitrogen in lesions was higher in trees inoculated with Ophiostoma montium or control trees, relative to Grosmannia clavigera or Leptographium longiclavatum. Furthermore, concentrations of ergosterol were higher in O. montium lesions compared to other tissues or treatments. These results suggest that O. montium differs from G. clavigera and L. longiclavatum in terms of acquiring nitrogen from host tissues and producing ergosterol.
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Affiliation(s)
- Sydne Guevara-Rozo
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Altaf Hussain
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Jonathan A Cale
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Jennifer G Klutsch
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | | | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
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Wang F, Cale JA, Erbilgin N. Induced Defenses of a Novel Host Tree Affect the Growth and Interactions of Bark Beetle-Vectored Fungi. MICROBIAL ECOLOGY 2020; 80:181-190. [PMID: 32020257 DOI: 10.1007/s00248-020-01490-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 01/27/2020] [Indexed: 06/10/2023]
Abstract
Mountain pine beetle (MPB) has recently expanded its host range to the novel jack pine forests in Alberta. Invasion success of MPB may depend on the outcome of interactions between its symbiotic fungus Grosmannia clavigera and Ophiostoma ips, a fungal associate of a potential competitor Ips pini. However, how the quality of jack pine phloem could influence interactions between the fungi is unknown. We investigated whether introduced concentrations of host nitrogen and monoterpenes affect the growth of and interaction between the fungi. Nitrogen concentrations did not affect the growth rate of either fungus. In the absence of monoterpenes, the presence of O. ips promoted G. clavigera growth. Monoterpenes either promoted or inhibited the growth of both fungi, and altered the outcome of species interactions from facilitation to no-effect. Overall, these results suggest that jack pine phloem quality and the presence of a niche-sharing fungus could influence MPB development.
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Affiliation(s)
- Fuai Wang
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Jonathan A Cale
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada.
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
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Cale JA, Klutsch JG, Dykstra CB, Peters B, Erbilgin N. Pathophysiological responses of pine defensive metabolites largely lack differences between pine species but vary with eliciting ophiostomatoid fungal species. TREE PHYSIOLOGY 2019; 39:1121-1135. [PMID: 30877758 DOI: 10.1093/treephys/tpz012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/18/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Phytopathogenic ophiostomatoid fungi are common associates of bark beetles and contribute to beetle-associated mortality of trees. Mountain pine beetle outbreaks in Canada are facilitating novel associations between its vectored fungi (Grosmannia clavigera, Leptographium longiclavatum and Ophiostoma montium) and jack pine. How the induced defense-related metabolite responses of jack and lodgepole pines vary in response to the fungi is unknown. Understanding this variation is important to clarifying pine susceptibility to and the physiological impacts of infection. We used a comparative metabolite profiling approach to investigate the defense-related signaling, carbon utilization/mobilization, and synthesis responses of both pines to the fungi. Both pine species largely exhibited similar metabolite responses to the fungi. The magnitude of pine metabolite responses positively reflected pathogen virulence. Our findings indicate that pines can recognize and metabolomically respond to novel pathogens, likely due to signals common between the novel fungi and fungi coevolved with the pine. Thus, jack pine is likely as susceptible as lodgepole pine to infections by each of the MPB-vectored fungi. Furthermore, the magnitude of the metabolite responses of both pines varied by the eliciting fungal species, with the most virulent pathogen causing the greatest reduction in carbohydrates and the highest accumulation of defensive terpenes.
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Affiliation(s)
- Jonathan A Cale
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada
| | - Jennifer G Klutsch
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada
| | - Christien B Dykstra
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada
| | - Brosnon Peters
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada
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Linnakoski R, Forbes KM. Pathogens-The Hidden Face of Forest Invasions by Wood-Boring Insect Pests. FRONTIERS IN PLANT SCIENCE 2019; 10:90. [PMID: 30804966 PMCID: PMC6378281 DOI: 10.3389/fpls.2019.00090] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/21/2019] [Indexed: 05/05/2023]
Affiliation(s)
- Riikka Linnakoski
- Natural Resources Institute Finland (Luke), Helsinki, Finland
- *Correspondence: Riikka Linnakoski
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McAllister CH, Fortier CE, St Onge KR, Sacchi BM, Nawrot MJ, Locke T, Cooke JEK. A novel application of RNase H2-dependent quantitative PCR for detection and quantification of Grosmannia clavigera, a mountain pine beetle fungal symbiont, in environmental samples. TREE PHYSIOLOGY 2018; 38:485-501. [PMID: 29329457 PMCID: PMC5982843 DOI: 10.1093/treephys/tpx147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/30/2017] [Indexed: 05/13/2023]
Abstract
Mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) is an economically and ecologically important pest of pine species in western North America. Mountain pine beetles form complex multipartite relationships with microbial partners, including the ophiostomoid fungi Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield, Ophiostoma montium (Rumbold) von Arx, Grosmannia aurea (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield, Leptographium longiclavatum (Lee, Kim, and Breuil) and Leptographium terebrantis (Barras and Perry). These fungi are vectored by MPB to new pine hosts, where the fungi overcome host defenses to grow into the sapwood. A tree's relative susceptibility to these fungi is conventionally assessed by measuring lesions that develop in response to fungal inoculation. However, these lesions represent a symptom of infection, representing both fungal growth and tree defense capacity. In order to more objectively assess fungal virulence and host tree susceptibility in studies of host-pathogen interactions, a reliable, consistent, sensitive method is required to accurately identify and quantify MPB-associated fungal symbionts in planta. We have adapted RNase H2-dependent PCR, a technique originally designed for rare allele discrimination, to develop a novel RNase H2-dependent quantitative PCR (rh-qPCR) assay that shows greater specificity and sensitivity than previously published PCR-based methods to quantify MPB fungal symbionts in pine xylem and MPB whole beetles. Two sets of assay probes were designed: one that amplifies a broad range of ophiostomoid species, and a second that amplifies G. clavigera but not other MPB-associated ophiostomoid species. Using these primers to quantify G. clavigera in pine stems, we provide evidence that lesion length does not accurately reflect the extent of fungal colonization along the stem nor the quantity of fungal growth within this colonized portion of stem. The sensitivity, specificity, reproducibility, cost effectiveness and high-throughput potential of the rh-qPCR assay makes the technology suitable for identification and quantification of a wide array of pathogenic and beneficial microbes that form associations with plants and other organisms, even when the microbial partner is present in low abundance.
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Affiliation(s)
- Chandra H McAllister
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Colleen E Fortier
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Kate R St Onge
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Bianca M Sacchi
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Meaghan J Nawrot
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Troy Locke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
- Corresponding author ()
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Cale JA, Muskens M, Najar A, Ishangulyyeva G, Hussain A, Kanekar SS, Klutsch JG, Taft S, Erbilgin N. Rapid monoterpene induction promotes the susceptibility of a novel host pine to mountain pine beetle colonization but not to beetle-vectored fungi. TREE PHYSIOLOGY 2017; 37:1597-1610. [PMID: 28985375 DOI: 10.1093/treephys/tpx089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Chemical induction can drive tree susceptibility to and host range expansions of attacking insects and fungi. Recently, mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) has expanded its host range from its historic host lodgepole pine (Pinus contorta var. latifolia Douglas ex Loudon) to jack pine (Pinus banksiana Lamb) in western Canada. Beetle success in jack pine forests likely depends upon the suitability of tree chemistry to MPB and its symbiotic phytopathogenic fungi. In particular, how rapid induced defenses of jack pine affect MPB colonization and the beetle's symbionts is unknown. In the field, we characterized and compared differences in rapid induced phloem monoterpenes between lodgepole and jack pines in response to various densities of Grosmannia clavigera (Robinson-Jeffery and Davidson)-a MPB symbiotic fungus used to simulate beetle attack-inoculations. Overall, lodgepole pine had higher limonene and myrcene, but lower α-pinene, concentrations than jack pine. However, myrcene concentrations in jack pine increased with inoculation density, while that in lodgepole pine did not respond to density treatments. We compared the growth and reproduction of MPB's symbiotic fungi, G. clavigera, Ophiostoma montium (Rumford) von Arx and Leptographium longiclavatum Lee, Kim and Breuil, grown on media amended with myrcene, α-pinene and limonene at concentrations reflecting two induction levels from each pine species. Myrcene and α-pinene amendments inhibited the growth but stimulated the reproduction of G. clavigera, whereas limonene stimulated its growth while inhibiting its reproduction. However, the growth and reproduction of the other fungi were generally stimulated by monoterpene amendments. Overall, our results suggest that jack pine rapid induction could promote MPB aggregation due to high levels of α-pinene (pheromone precursor), a positive feedback of myrcene (pheromone synergist) and low levels of limonene (resistance). Jack pine is likely as susceptible to MPB-vectored fungi as lodgepole pine, indicating that jack pine induction will likely not adversely affect symbiont activities enough to inhibit the invasion of MPB into jack pine forests.
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Affiliation(s)
- Jonathan A Cale
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Marlena Muskens
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Ahmed Najar
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Guncha Ishangulyyeva
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Altaf Hussain
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Sanat S Kanekar
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Jennifer G Klutsch
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Spencer Taft
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada
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Ojeda Alayon DI, Tsui CKM, Feau N, Capron A, Dhillon B, Zhang Y, Massoumi Alamouti S, Boone CK, Carroll AL, Cooke JEK, Roe AD, Sperling FAH, Hamelin RC. Genetic and genomic evidence of niche partitioning and adaptive radiation in mountain pine beetle fungal symbionts. Mol Ecol 2017; 26:2077-2091. [PMID: 28231417 DOI: 10.1111/mec.14074] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 12/08/2016] [Accepted: 02/09/2017] [Indexed: 12/19/2022]
Abstract
Bark beetles form multipartite symbiotic associations with blue stain fungi (Ophiostomatales, Ascomycota). These fungal symbionts play an important role during the beetle's life cycle by providing nutritional supplementation, overcoming tree defences and modifying host tissues to favour brood development. The maintenance of stable multipartite symbioses with seemingly less competitive symbionts in similar habitats is of fundamental interest to ecology and evolution. We tested the hypothesis that the coexistence of three fungal species associated with the mountain pine beetle is the result of niche partitioning and adaptive radiation using SNP genotyping coupled with genotype-environment association analysis and phenotypic characterization of growth rate under different temperatures. We found that genetic variation and population structure within each species is best explained by distinct spatial and environmental variables. We observed both common (temperature seasonality and the host species) and distinct (drought, cold stress, precipitation) environmental and spatial factors that shaped the genomes of these fungi resulting in contrasting outcomes. Phenotypic intraspecific variations in Grosmannia clavigera and Leptographium longiclavatum, together with high heritability, suggest potential for adaptive selection in these species. By contrast, Ophiostoma montium displayed narrower intraspecific variation but greater tolerance to extreme high temperatures. Our study highlights unique phenotypic and genotypic characteristics in these symbionts that are consistent with our hypothesis. By maintaining this multipartite relationship, the bark beetles have a greater likelihood of obtaining the benefits afforded by the fungi and reduce the risk of being left aposymbiotic. Complementarity among species could facilitate colonization of new habitats and survival under adverse conditions.
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Affiliation(s)
- Dario I Ojeda Alayon
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Clement K M Tsui
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Nicolas Feau
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Arnaud Capron
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Braham Dhillon
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Yiyuan Zhang
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Sepideh Massoumi Alamouti
- Department of Wood Science, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Celia K Boone
- Ecosystem Science and Management Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada, V2N 4Z9
| | - Allan L Carroll
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2R3
| | - Amanda D Roe
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2R3.,Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, 1219 Queen St E, Sault Ste. Marie, ON, Canada, P6A 2E5
| | - Felix A H Sperling
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2R3
| | - Richard C Hamelin
- Department of Forest and Conservation Sciences, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4.,Institut de Biologie Intégrative des Systèmes, Université Laval, 1030 Avenue de la Médecine, Québec City, QC, Canada, G1V 0A6
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17
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Cale JA, Collignon RM, Klutsch JG, Kanekar SS, Hussain A, Erbilgin N. Fungal Volatiles Can Act as Carbon Sources and Semiochemicals to Mediate Interspecific Interactions Among Bark Beetle-Associated Fungal Symbionts. PLoS One 2016; 11:e0162197. [PMID: 27583519 PMCID: PMC5008770 DOI: 10.1371/journal.pone.0162197] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/18/2016] [Indexed: 11/18/2022] Open
Abstract
Mountain pine beetle (Dendroctonus ponderosae) has killed millions of hectares of pine forests in western North America. Beetle success is dependent upon a community of symbiotic fungi comprised of Grosmannia clavigera, Ophiostoma montium, and Leptographium longiclavatum. Factors regulating the dynamics of this community during pine infection are largely unknown. However, fungal volatile organic compounds (FVOCs) help shape fungal interactions in model and agricultural systems and thus may be important drivers of interactions among bark beetle-associated fungi. We investigated whether FVOCs can mediate interspecific interactions among mountain pine beetle's fungal symbionts by affecting fungal growth and reproduction. Headspace volatiles were collected and identified to determine species-specific volatile profiles. Interspecific effects of volatiles on fungal growth and conidia production were assessed by pairing physically-separated fungal cultures grown either on a carbon-poor or -rich substrate, inside a shared-headspace environment. Fungal VOC profiles differed by species and influenced the growth and/or conidia production of the other species. Further, our results showed that FVOCs can be used as carbon sources for fungi developing on carbon-poor substrates. This is the first report demonstrating that FVOCs can drive interactions among bark beetle fungal symbionts, and thus are important factors in beetle attack success.
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Affiliation(s)
- Jonathan A Cale
- Department of Renewable Resources, 4-42 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - R Maxwell Collignon
- Department of Entomology, Entomology Building, University of California, Riverside, CA, 92521, United States of America
| | - Jennifer G Klutsch
- Department of Renewable Resources, 4-42 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Sanat S Kanekar
- Department of Renewable Resources, 4-42 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Altaf Hussain
- Department of Renewable Resources, 4-42 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, 4-42 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
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18
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Chemodiversity and biodiversity of fungi associated with the pine weevil Hylobius abietis. Fungal Biol 2015; 119:738-46. [DOI: 10.1016/j.funbio.2015.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/26/2015] [Accepted: 04/28/2015] [Indexed: 11/20/2022]
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Bracewell RR, Six DL. Broadscale specificity in a bark beetle-fungal symbiosis: a spatio-temporal analysis of the mycangial fungi of the western pine beetle. MICROBIAL ECOLOGY 2014; 68:859-870. [PMID: 25004995 DOI: 10.1007/s00248-014-0449-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/19/2014] [Indexed: 06/03/2023]
Abstract
Whether and how mutualisms are maintained through ecological and evolutionary time is a seldom studied aspect of bark beetle-fungal symbioses. All bark beetles are associated with fungi and some species have evolved structures for transporting their symbiotic partners. However, the fungal assemblages and specificity in these symbioses are not well known. To determine the distribution of fungi associated with the mycangia of the western pine beetle (Dendroctonus brevicomis), we collected beetles from across the insect's geographic range including multiple genetically distinct populations. Two fungi, Entomocorticium sp. B and Ceratocystiopsis brevicomi, were isolated from the mycangia of beetles from all locations. Repeated sampling at two sites in Montana found that Entomocorticium sp. B was the most prevalent fungus throughout the beetle's flight season, and that females carrying that fungus were on average larger than females carrying C. brevicomi. We present evidence that throughout the flight season, over broad geographic distances, and among genetically distinct populations of beetle, the western pine beetle is associated with the same two species of fungi. In addition, we provide evidence that one fungal species is associated with larger adult beetles and therefore might provide greater benefit during beetle development. The importance and maintenance of this bark beetle-fungus interaction is discussed.
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Affiliation(s)
- Ryan R Bracewell
- Department of Ecosystem and Conservation Sciences, College of Forestry, The University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA,
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20
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Tsui CKM, Farfan L, Roe AD, Rice AV, Cooke JEK, El-Kassaby YA, Hamelin RC. Population structure of mountain pine beetle symbiont Leptographium longiclavatum and the implication on the multipartite beetle-fungi relationships. PLoS One 2014; 9:e105455. [PMID: 25153489 PMCID: PMC4143264 DOI: 10.1371/journal.pone.0105455] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 07/24/2014] [Indexed: 12/26/2022] Open
Abstract
Over 18 million ha of forests have been destroyed in the past decade in Canada by the mountain pine beetle (MPB) and its fungal symbionts. Understanding their population dynamics is critical to improving modeling of beetle epidemics and providing potential clues to predict population expansion. Leptographium longiclavatum and Grosmannia clavigera are fungal symbionts of MPB that aid the beetle to colonize and kill their pine hosts. We investigated the genetic structure and demographic expansion of L. longiclavatum in populations established within the historic distribution range and in the newly colonized regions. We identified three genetic clusters/populations that coincide with independent geographic locations. The genetic profiles of the recently established populations in northern British Columbia (BC) and Alberta suggest that they originated from central and southern BC. Approximate Bayesian Computation supports the scenario that this recent expansion represents an admixture of individuals originating from BC and the Rocky Mountains. Highly significant correlations were found among genetic distance matrices of L. longiclavatum, G. clavigera, and MPB. This highlights the concordance of demographic processes in these interacting organisms sharing a highly specialized niche and supports the hypothesis of long-term multipartite beetle-fungus co-evolutionary history and mutualistic relationships.
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Affiliation(s)
- Clement Kin-Ming Tsui
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lina Farfan
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amanda D. Roe
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Adrianne V. Rice
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Janice E. K. Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Yousry A. El-Kassaby
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard C. Hamelin
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Natural Resources Canada, Canadian Forest Services, Laurentian Forestry Centre, Québec City, Québec, Canada
- * E-mail:
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21
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Meléndez L, Laiolo P, Mironov S, García M, Magaña O, Jovani R. Climate-driven variation in the intensity of a host-symbiont animal interaction along a broad elevation gradient. PLoS One 2014; 9:e101942. [PMID: 25025873 PMCID: PMC4099072 DOI: 10.1371/journal.pone.0101942] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 06/13/2014] [Indexed: 11/18/2022] Open
Abstract
Gradients of environmental stress may affect biotic interactions in unpredictable ways responding to climate variation, depending on the abiotic stress tolerance of interacting partners. Here, we study the effect of local climate on the intensity of feather mites in six mountain passerines along a 1400 m elevational gradient characterized by shifting temperature and rainfall. Although obligatory symbionts of warm-blooded organisms are assumed to live in mild and homeothermic environments, those inhabiting external, non-blood-irrigated body portions of the host organism, such as feather mites, are expected to endure exposure to the direct influence of a fluctuating climate. As expected, feather mite intensity declined with elevation in all bird species, a pattern that was also found in cold-adapted passerines that have typical alpine habits. The elevation cline was mainly explained by a positive effect of the average temperature upon mite intensity in five of the six species studied. Precipitation explained less variance in mite intensity than average temperature, and showed a negative correlation in half of the studied species. We found no climate-driven migration of mites along the wings of birds, no replacement of mite species along elevation gradients and no association with available food resources for mites (estimated by the size of the uropygial gland). This study suggests that ectosymbionts of warm-blooded animals may be highly sensitive to climatic variation and become less abundant under stressful environmental conditions, providing empirical evidence of the decline of specialized biotic interactions among animal species at high elevations.
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Affiliation(s)
- Leandro Meléndez
- Research Unit of Biodiversity (UO, CSIC, PA), Oviedo University, Campus de Mieres, Mieres, Spain
| | - Paola Laiolo
- Research Unit of Biodiversity (UO, CSIC, PA), Oviedo University, Campus de Mieres, Mieres, Spain
| | - Sergey Mironov
- Zoological Institute, Russian Academy of Sciences, Universitetskaya Embankment 1, Saint Petersburg, Russia
| | - Mónica García
- Research Unit of Biodiversity (UO, CSIC, PA), Oviedo University, Campus de Mieres, Mieres, Spain
| | - Oscar Magaña
- Research Unit of Biodiversity (UO, CSIC, PA), Oviedo University, Campus de Mieres, Mieres, Spain
| | - Roger Jovani
- Department of Evolutionary Ecology, Estación Biológica de Doñana (CSIC), Avda, Americo Vespucio s/n, Sevilla, Spain
- * E-mail:
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Blaalid R, Davey ML, Kauserud H, Carlsen T, Halvorsen R, Høiland K, Eidesen PB. Arctic root-associated fungal community composition reflects environmental filtering. Mol Ecol 2014; 23:649-59. [DOI: 10.1111/mec.12622] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 12/01/2022]
Affiliation(s)
- Rakel Blaalid
- Department of Biology; Microbial Evolution Research Group (MERG); University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
| | - Marie L. Davey
- The University Centre in Svalbard; PO Box 156 NO-9171 Longyearbyen Norway
| | - Håvard Kauserud
- Department of Biology; Microbial Evolution Research Group (MERG); University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
| | - Tor Carlsen
- Department of Biology; Microbial Evolution Research Group (MERG); University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
| | - Rune Halvorsen
- Natural History Museum; University of Oslo; PO Box 1172 Blindern NO-0318 Oslo Norway
| | - Klaus Høiland
- Department of Biology; Microbial Evolution Research Group (MERG); University of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
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Watanabe K, Murakami M, Hirao T, Kamata N. Species diversity estimation of ambrosia and bark beetles in temperate mixed forests in Japan based on host phylogeny and specificity. Ecol Res 2014. [DOI: 10.1007/s11284-013-1123-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ojeda DI, Dhillon B, Tsui CKM, Hamelin RC. Single-nucleotide polymorphism discovery in Leptographium longiclavatum, a mountain pine beetle-associated symbiotic fungus, using whole-genome resequencing. Mol Ecol Resour 2013; 14:401-10. [PMID: 24152017 DOI: 10.1111/1755-0998.12191] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/05/2013] [Accepted: 10/07/2013] [Indexed: 11/29/2022]
Abstract
Single-nucleotide polymorphisms (SNPs) are rapidly becoming the standard markers in population genomics studies; however, their use in nonmodel organisms is limited due to the lack of cost-effective approaches to uncover genome-wide variation, and the large number of individuals needed in the screening process to reduce ascertainment bias. To discover SNPs for population genomics studies in the fungal symbionts of the mountain pine beetle (MPB), we developed a road map to discover SNPs and to produce a genotyping platform. We undertook a whole-genome sequencing approach of Leptographium longiclavatum in combination with available genomics resources of another MPB symbiont, Grosmannia clavigera. We sequenced 71 individuals pooled into four groups using the Illumina sequencing technology. We generated between 27 and 30 million reads of 75 bp that resulted in a total of 1, 181 contigs longer than 2 kb and an assembled genome size of 28.9 Mb (N50 = 48 kb, average depth = 125x). A total of 9052 proteins were annotated, and between 9531 and 17,266 SNPs were identified in the four pools. A subset of 206 genes (containing 574 SNPs, 11% false positives) was used to develop a genotyping platform for this species. Using this roadmap, we developed a genotyping assay with a total of 147 SNPs located in 121 genes using the Illumina(®) Sequenom iPLEX Gold. Our preliminary genotyping (success rate = 85%) of 304 individuals from 36 populations supports the utility of this approach for population genomics studies in other MPB fungal symbionts and other fungal nonmodel species.
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Affiliation(s)
- Dario I Ojeda
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z4
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25
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Kolařík M, Jankowiak R. Vector affinity and diversity of Geosmithia fungi living on subcortical insects inhabiting Pinaceae species in central and northeastern Europe. MICROBIAL ECOLOGY 2013; 66:682-700. [PMID: 23624540 DOI: 10.1007/s00248-013-0228-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 04/08/2013] [Indexed: 06/02/2023]
Abstract
Fungi from the genus Geosmithia (Ascomycota: Hypocreales) are associated with bark beetles (Coleoptera: Scolytinae), though little is known about ecology, diversity, and distribution of these fungi across beetle and its host tree species. This study surveyed the diversity, distribution and vector affinity of Geosmithia isolated from subcortical insects that colonized trees from the family Pinaceae in Central and Northeastern Europe. Twelve Geosmithia species were isolated from 85 plant samples associated with 23 subcortical insect species (including 14 bark beetle species). Geosmithia community composition was similar across different localities and vector species; although the fungal communities associated with insects that colonized Pinus differed from that colonizing other tree species (Abies, Larix, and Picea). Ten Geosmithia species from four independent phylogenetic lineages were not reported previously from vectors feeding on other plant families and seem to be restricted to the vectors from Pinaceae only. We conclude that presence of such substrate specificity suggests a long and stable association between Geosmithia and bark beetles.
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Affiliation(s)
- Miroslav Kolařík
- Institute of Microbiology of the ASCR, v. v. i., Vídeňská 1083, 142 20, Prague 4, Czech Republic,
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Hussa EA, Goodrich-Blair H. It Takes a Village: Ecological and Fitness Impacts of Multipartite Mutualism. Annu Rev Microbiol 2013; 67:161-78. [DOI: 10.1146/annurev-micro-092412-155723] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Elizabeth A. Hussa
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706; ,
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The bark beetle holobiont: why microbes matter. J Chem Ecol 2013; 39:989-1002. [PMID: 23846183 DOI: 10.1007/s10886-013-0318-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 06/19/2013] [Accepted: 06/27/2013] [Indexed: 01/20/2023]
Abstract
All higher organisms are involved in symbioses with microbes. The importance of these partnerships has led to the concept of the holobiont, defined as the animal or plant with all its associated microbes. Indeed, the interactions between insects and symbionts form much of the basis for the success and diversity of this group of arthropods. Insects rely on microbes to perform basic life functions and to exploit resources and habitats. By "partnering" with microbes, insects access new genomic variation instantaneously allowing the exploitation of new adaptive zones, influencing not only outcomes in ecological time, but the degree of innovation and change that occurs over evolutionary time. In this review, I present a brief overview of the importance of insect-microbe holobionts to illustrate how critical an understanding of the holobiont is to understanding the insect host and it interactions with its environment. I then review what is known about the most influential insect holobionts in many forest ecosystems-bark beetles and their microbes-and how new approaches and technologies are allowing us to illuminate how these symbioses function. Finally, I discuss why it will be critical to study bark beetles as a holobiont to understand the ramifications and extent of anthropogenic change in forest ecosystems.
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Popa V, Déziel E, Lavallée R, Bauce E, Guertin C. The complex symbiotic relationships of bark beetles with microorganisms: a potential practical approach for biological control in forestry. PEST MANAGEMENT SCIENCE 2012; 68:963-75. [PMID: 22566204 DOI: 10.1002/ps.3307] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/10/2012] [Accepted: 02/15/2012] [Indexed: 05/14/2023]
Abstract
Bark beetles, especially Dendroctonus species, are considered to be serious pests of the coniferous forests in North America. Bark beetle forest pests undergo population eruptions, causing region wide economic losses. In order to save forests, finding new and innovative environmentally friendly approaches in wood-boring insect pest management is more important than ever. Several biological control methods have been attempted over time to limit the damage and spreading of bark beetle epidemics. The use of entomopathogenic microorganisms against bark beetle populations is an attractive alternative tool for many biological control programmes in forestry. However, the effectiveness of these biological control agents is strongly affected by environmental factors, as well as by the susceptibility of the insect host. Bark beetle susceptibility to entomopathogens varies greatly between species. According to recent literature, bark beetles are engaged in symbiotic relationships with fungi and bacteria. These types of relationship are very complex and apparently involved in bark beetle defensive mechanisms against pathogens. The latest scientific discoveries in multipartite symbiosis have unravelled unexpected opportunities in bark beetle pest management, which are discussed in this article.
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Affiliation(s)
- Valentin Popa
- INRS-Institut Armand-Frappier, Laval, Quebec, Canada
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Giordano L, Garbelotto M, Nicolotti G, Gonthier P. Characterization of fungal communities associated with the bark beetle Ips typographus varies depending on detection method, location, and beetle population levels. Mycol Prog 2012. [DOI: 10.1007/s11557-012-0822-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Six DL. Ecological and Evolutionary Determinants of Bark Beetle -Fungus Symbioses. INSECTS 2012; 3:339-66. [PMID: 26467964 PMCID: PMC4553632 DOI: 10.3390/insects3010339] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 03/01/2012] [Accepted: 03/15/2012] [Indexed: 11/23/2022]
Abstract
Ectosymbioses among bark beetles (Curculionidae, Scolytinae) and fungi (primarily ophiostomatoid Ascomycetes) are widespread and diverse. Associations range from mutualistic to commensal, and from facultative to obligate. Some fungi are highly specific and associated only with a single beetle species, while others can be associated with many. In addition, most of these symbioses are multipartite, with the host beetle associated with two or more consistent partners. Mycangia, structures of the beetle integument that function in fungal transport, have evolved numerous times in the Scolytinae. The evolution of such complex, specialized structures indicates a high degree of mutual dependence among the beetles and their fungal partners. Unfortunately, the processes that shaped current day beetle-fungus symbioses remain poorly understood. Phylogeny, the degree and type of dependence on partners, mode of transmission of symbionts (vertical vs. horizontal), effects of the abiotic environment, and interactions among symbionts themselves or with other members of the biotic community, all play important roles in determining the composition, fidelity, and longevity of associations between beetles and their fungal associates. In this review, I provide an overview of these associations and discuss how evolution and ecological processes acted in concert to shape these fascinating, complex symbioses.
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Affiliation(s)
- Diana L Six
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA.
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Tsui CKM, Roe AD, El-Kassaby YA, Rice AV, Alamouti SM, Sperling FAH, Cooke JEK, Bohlmann J, Hamelin RC. Population structure and migration pattern of a conifer pathogen, Grosmannia clavigera, as influenced by its symbiont, the mountain pine beetle. Mol Ecol 2011; 21:71-86. [PMID: 22118059 DOI: 10.1111/j.1365-294x.2011.05366.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the population structure of Grosmannia clavigera (Gc), a fungal symbiont of the mountain pine beetle (MPB) that plays a crucial role in the establishment and reproductive success of this pathogen. This insect-fungal complex has destroyed over 16 million ha of lodgepole pine forests in Canada, the largest MPB epidemic in recorded history. During this current epidemic, MPB has expanded its range beyond historically recorded boundaries, both northward and eastward, and has now reached the jack pine of Alberta, potentially threatening the Canadian boreal forest. To better understand the dynamics between the beetle and its fungal symbiont, we sampled 19 populations in western North America and genotyped individuals from these populations with eight microsatellite markers. The fungus displayed high haplotype diversity, with over 250 unique haplotypes observed in 335 single spore isolates. Linkage equilibria in 13 of the 19 populations suggested that the fungus reproduces sexually. Bayesian clustering and distance analyses identified four genetic clusters that corresponded to four major geographical regions, which suggested that the epidemic arose from multiple geographical sources. A genetic cluster north of the Rocky Mountains, where the MPB has recently become established, experienced a population bottleneck, probably as a result of the recent range expansion. The two genetic clusters located north and west of the Rocky Mountains contained many fungal isolates admixed from all populations, possibly due to the massive movement of MPB during the epidemic. The general agreement in north-south differentiation of MPB and G. clavigera populations points to the fungal pathogen's dependence on the movement of its insect vector. In addition, the patterns of diversity and the individual assignment tests of the fungal associate suggest that migration across the Rocky Mountains occurred via a northeastern corridor, in accordance with meteorological patterns and observation of MPB movement data. Our results highlight the potential of this pathogen for both expansion and sexual reproduction, and also identify some possible barriers to gene flow. Understanding the ecological and evolutionary dynamics of this fungus-beetle association is important for the modelling and prediction of MPB epidemics.
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Affiliation(s)
- Clement K M Tsui
- Department of Forest Sciences, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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