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Zaman R, Shah A, Ishangulyyeva G, Erbilgin N. Exploring behavioural and physiological adaptations in mountain pine beetle in response to elevated ozone concentrations. CHEMOSPHERE 2024; 362:142751. [PMID: 38960047 DOI: 10.1016/j.chemosphere.2024.142751] [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: 03/31/2024] [Revised: 06/23/2024] [Accepted: 06/30/2024] [Indexed: 07/05/2024]
Abstract
Elevated ozone (eO3) concentrations pose a threat to insect populations by potentially altering their behaviour and physiology. This study investigates the effects of eO3 concentrations on the mountain pine beetle which is a major tree-killing species of conifers in northwestern North America. We are particularly interested in understanding the effects of eO3 concentrations on beetle behaviour and physiology and possible transgenerational impacts on bark beetle broods. We conducted O3-enrichment experiments in a controlled laboratory setting using different O3 concentrations (100-200 ppb; projected for 2050-2100) and assessed various beetle responses, including CO2 respiration, mating behaviour, survival probability, locomotion, and attraction behaviour. Transgenerational impacts on the first and second generations were also analyzed by studying brood morphology, mating behaviour, survival, and pheromone production. We found that beetles exposed to eO3 concentrations had shorter oviposition galleries and reduced brood production. Beetle pheromones were also degraded by eO3 exposure. However, exposure to eO3 also prompted various adaptive responses in beetles. Despite reduced respiration, eO3 improved locomotor activity and the olfactory response of beetles. Surprisingly, beetle survival probability was also improved both in the parents and their broods. We also observed transgenerational plasticity in the broods of eO3-exposed parents, suggesting potential stress resistance mechanisms. This was evident by similar mating success, oviposition gallery length, and brood numbers produced in both control and eO3 concentration treatments. This study demonstrates the sensitivity of mountain pine beetles to increased O3 concentrations, contributing crucial insights into the ecological implications of eO3 concentrations on their populations. Overall, the outcome of this study contributes to informed climate change mitigation strategies and adaptive management practices for the development of resilient forests in response to emerging forest insect pests worldwide.
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Affiliation(s)
- Rashaduz Zaman
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada.
| | - Ateeq Shah
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
| | - Guncha Ishangulyyeva
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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Zaman R, Shah A, Shah A, Ullah A, Ishangulyyeva G, Erbilgin N. Unraveling the multifaceted effects of climatic factors on mountain pine beetle and its interaction with fungal symbionts. GLOBAL CHANGE BIOLOGY 2024; 30:e17207. [PMID: 38413744 DOI: 10.1111/gcb.17207] [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: 11/24/2023] [Revised: 01/24/2024] [Accepted: 02/10/2024] [Indexed: 02/29/2024]
Abstract
Mountain pine beetles (MPBs) pose a substantial threat to North American pine forests, causing extensive tree mortality over large areas. Their tree-killing ability is closely linked to mass aggregation on host trees triggered via pheromones and dependence on their symbiotic fungi. However, the influence of a changing climate on the biology of MPBs and their co-evolved interactions with their fungal symbionts remains uncertain. To investigate this, male and female pairs of beetles were introduced into freshly cut logs from lodgepole pine trees and placed in controlled climate chambers with manipulated environmental conditions, including two levels of CO2 (ambient vs. 1000 ppm), O3 (ambient vs. 100 ppb) and humidity (33% vs. 65%). The beetle-infested logs were left in these chambers for 1 month and then returned to ambient conditions until brood emergence. Emerging broods were collected for further analysis. Additionally, three species of fungal symbionts (Grosmannia clavigera, Ophiostoma montium and Leptographium longiclavatum) were subjected to the same CO2 , O3 and humidity conditions for 5 days. Lower humidity promoted MPB reproduction and fungal growth. Elevated CO2 accelerated larval growth and emergence while improving brood pheromone production. Elevated O3 had a negative impact on MPB reproduction and brood fitness while improving its immune responses to an entomopathogenic fungus (Beauveria bassiana). It also inhibited fungal growth and reproduction, whereas elevated CO2 had varied (positive or negative) effects on fungal growth and ergosterol (proxy to fungal mass) production depending on the fungal species. Together, these findings suggest that climate change can potentially alter the interactions between MPBs and their fungal symbionts, highlighting the importance of understanding how climate change affects forest pests and their symbiotic relationships to develop effective management strategies in the future.
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Affiliation(s)
- Rashaduz Zaman
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Aftab Shah
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Ateeq Shah
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Aziz Ullah
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Guncha Ishangulyyeva
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
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Wang Z, Liu Y, Wang H, Roy A, Liu H, Han F, Zhang X, Lu Q. Genome and transcriptome of Ips nitidus provide insights into high-altitude hypoxia adaptation and symbiosis. iScience 2023; 26:107793. [PMID: 37731610 PMCID: PMC10507238 DOI: 10.1016/j.isci.2023.107793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/15/2023] [Accepted: 08/29/2023] [Indexed: 09/22/2023] Open
Abstract
Ips nitidus is a well-known conifer pest that has contributed significantly to spruce forest disturbance in the Qinghai-Tibet Plateau and seriously threatens the ecological balance of these areas. We report a chromosome-level genome of I. nitidus determined by PacBio and Hi-C technology. Phylogenetic inference showed that it diverged from the common ancestor of I. typographus ∼2.27 mya. Gene family expansion in I. nitidus was characterized by DNA damage repair and energy metabolism, which may facilitate adaptation to high-altitude hypoxia. Interestingly, differential gene expression analysis revealed upregulated genes associated with high-altitude hypoxia adaptation and downregulated genes associated with detoxification after feeding and tunneling in fungal symbiont Ophiostoma bicolor-colonized substrates. Our findings provide evidence of the potential adaptability of I. nitidus to conifer host, high-altitude hypoxia and insight into how fungal symbiont assist in this process. This study enhances our understanding of insect adaptation, symbiosis, and pest management.
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Affiliation(s)
- Zheng Wang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China
| | - Ya Liu
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Huimin Wang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Amit Roy
- Faculty of Forestry and Wood Sciences, EXTEMIT-K and EVA.4.0 Unit, Czech University of Life Sciences, Kamýcká 1176, Prague 6, 165 00 Suchdol, Czech Republic
| | - Huixiang Liu
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China
| | | | - Xingyao Zhang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Quan Lu
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
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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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Shi X, Fang J, Du H, Zhang S, Liu F, Zhang Z, Kong X. Performance of two Ips bark beetles and their associated pathogenic fungi on hosts reflects a species-specific association in the beetle-fungus complex. FRONTIERS IN PLANT SCIENCE 2022; 13:1029526. [PMID: 36483952 PMCID: PMC9722963 DOI: 10.3389/fpls.2022.1029526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 10/25/2022] [Indexed: 06/17/2023]
Abstract
When Ips bark beetles invade and colonize the host plants, their associated pathogenic fungal partners are carried into the phloem of the host trees. Host trees are lethally attacked by the beetle-fungus complex and the collective damage severely limits forestry production worldwide. It is of great importance to verify whether bark beetles and their associated fungi show concordant performance in terms of biology, physiology, and biochemistry on host trees. In this study, the two Ips bark beetles Ips typographus and Ips subelongatus (Coleoptera: Curculionidae, Scolytinae), their respective associated pathogenic fungi Endoconidiophora polonica and Endoconidiophora fujiensis, and their respective host plants Picea jezoensis and Larix olgensis were selected as test material. Cross-inoculation experiments were conducted indoors and outdoors to investigate the differences in reproduction and development of two beetles and infectivity of two fungi on two plants, as well as the differences in physiological responses of two plants to two fungal infections. The results showed that I. typographus and E. polonica had excellent host performance on P. jezoensis; however, neither successfully colonized and infected L. olgensis. In contrast, I. subelongatus and E. fujiensis showed strong host suitability on L. olgensis and some degree of suitability on P. jezoensis, although the host suitability of P. jezoensis for E. polonica was significantly higher than that for E. fujiensis. In addition, we found that the absolute amount of ergosterol accumulated on the lesion was positively correlated with lesion area. The ergosterol amount and lesion area were both strongly correlated with the release of host monoterpenes, but had no obvious correlation with the concentration of fungi-induced phenols on the lesion area and the side-chain oxidation of lignin in the xylem of the infected sites. Based on these results, we confirmed that "I. typographus-E. polonica" and "I. subelongatus-E. fujiensis" complexes both showed the most suitable consistent performances on their own traditional hosts, establishing a stable species-specific association relationship in these two beetle-fungus complexes, with the "I. subelongatus-E. fujiensis" complex showing broader host suitability. From the perspective of physiological responses of plants to fungal infections, monoterpenes are an important indicator of host suitability.
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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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Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity. FORESTS 2021. [DOI: 10.3390/f12121795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ophiostomatoid fungi are known for their associations with bark beetles, and some species are important sources of tree diseases. Ceratocystiopsis is a genus of the ophiostomatoid fungi in order Ophiostomatales. The shortage of DNA barcodes for many species in this genus has resulted in the presence of many unnamed cryptic species. In this study, Ceratocystiopsis subelongati sp. nov. associated with Ips subelongatus infesting Pinus sylvestris var. mongolica in Inner Mongolia, China, was identified and described based on phylogenetic inference of multi-gene DNA sequences and morphological characteristics. The species is characterized by a hyalorhinocladiella- to sporothrix-like asexual state and an optimal growth temperature of 30 °C. Artificial inoculation tests in the field showed that it is mildly pathogenic to five-year-old larch trees, the main host of I. subelongatus. It is also the first described Ceratocystiopsis species associated with I. subelongatus in China. This discovery should provide new avenues for studying the symbiosis between bark beetles and ophiostomatoid fungi.
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