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Pasques O, Munné-Bosch S. Ancient trees are essential elements for high-mountain forest conservation: Linking the longevity of trees to their ecological function. Proc Natl Acad Sci U S A 2024; 121:e2317866121. [PMID: 38315840 PMCID: PMC10873607 DOI: 10.1073/pnas.2317866121] [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: 10/13/2023] [Accepted: 12/24/2023] [Indexed: 02/07/2024] Open
Abstract
Mature forests and their extremely old trees are rare and threatened ancient vestiges in remote European high-mountain regions. Here, we analyze the role that extremely long-living trees have in mature forests biodiversity in relation to their singular traits underlying longevity. Tree size and age determine relative growth rates, bud abortion, and the water status of long-living trees. The oldest trees suffer indefectible age-related constraints but possess singular evolutionary traits defined by fitness adaptation, modular autonomy, and a resilient metabolism that allow them to have irreplaceable roles in the ecosystem as biodiversity anchors of vulnerable lichen species like Letharia vulpina. We suggest that the role of ancient trees as unique biodiversity reservoirs is linked to their singular physiological traits associated with longevity. The set of evolutionarily plastic tools that can only be provided by centuries or millennia of longevity helps the oldest trees of mature forests drive singular ecological relationships that are irreplaceable and necessary for ecosystem dynamics.
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Affiliation(s)
- Ot Pasques
- Department of Evolutionary Biology, Ecology and Environmental Science, University of Barcelona, Barcelona08028, Spain
- Research Institute in Biodiversity, University of Barcelona, Barcelona08028, Spain
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Science, University of Barcelona, Barcelona08028, Spain
- Research Institute in Biodiversity, University of Barcelona, Barcelona08028, Spain
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2
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Cui J, Li X, Lu Z, Jin B. Plant secondary metabolites involved in the stress tolerance of long-lived trees. TREE PHYSIOLOGY 2024; 44:tpae002. [PMID: 38196002 DOI: 10.1093/treephys/tpae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 12/29/2023] [Indexed: 01/11/2024]
Abstract
Ancient trees are natural wonders because of their longevity, having lived for hundreds or thousands of years, and their ability to withstand changing environments and a variety of stresses. These long-lived trees have sophisticated defense mechanisms, such as the production of specialized plant metabolites (SPMs). In this review, we provide an overview of the major biotic and abiotic stresses that long-lived trees often face, as well as an analysis of renowned ancient tree species and their unique protective SPMs against environmental stressors. We also discuss the synthesis and accumulation of defensive SPMs induced by environmental factors and endophytes in these trees. Furthermore, we conducted a comparative genomic analysis of 17 long-lived tree species and discovered significant expansions of SPM biosynthesis gene families in these species. Our comprehensive review reveals the crucial role of SPMs in high resistance in long-lived trees, providing a novel natural resource for plant defense, crop improvement and even the pharmaceutical industry.
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Affiliation(s)
- Jiawen Cui
- College of Horticulture and Landscape, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, China
| | - Xiang Li
- College of Horticulture and Landscape, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, China
| | - Zhaogeng Lu
- College of Horticulture and Landscape, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, China
| | - Biao Jin
- College of Horticulture and Landscape, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, China
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College, Yangzhou University, 48 East Wenhui Road, Yangzhou, China
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3
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Pasques O, Munné-Bosch S. Physiological mechanisms underlying extreme longevity in mountain pine trees. PLANT PHYSIOLOGY 2023; 191:974-985. [PMID: 36440969 PMCID: PMC9922391 DOI: 10.1093/plphys/kiac540] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Ancient trees are life history longevity winners that mostly persist in remote and environmentally harsh mountainous areas. Here, we performed a multifeature analysis in a protected mature mountain pine (Pinus uncinata) forest to identify the morphological and physiological traits that make these trees unique. We compared the physiology of meristematic and somatic tissues (apical buds and needles, respectively) from juvenile, mature young, mature old, and mature ancient trees under cold stress and nonstress conditions. We successfully identified key morphological features of extreme longevity at the organism level, as well as various growth, vigor, stress, and dormancy markers underlying extreme longevity in old and ancient trees. Results indicated that evolution has exerted selective pressure on specific physiological traits that make trees become longevity winners (<0.1% of the tree population were ancient trees, with an average trunk diameter >100 cm and an estimated age of 700 years). Traits entailing longevity not only included apical dominance loss, epicormic growth, and modular senescence, but also an extreme plasticity in both meristematic and somatic tissues (buds and needles, respectively), as shown by various physiological markers. In conclusion, ancient trees are oddities that not only possess a unique ecological value but also show divergent physiological behaviors selected during their evolution to allow them to cope with adversities and attain long life.
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Affiliation(s)
- Ot Pasques
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona 08028, Spain
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona 08028, Spain
- Research Institute in Biodiversity (IRBio), University of Barcelona, Barcelona 08028, Spain
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4
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Constitutive and Induced Defenses in Long-lived Pines Do Not Trade Off but Are Influenced by Climate. J Chem Ecol 2022; 48:746-760. [PMID: 35982356 DOI: 10.1007/s10886-022-01377-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 10/15/2022]
Abstract
Plants resist herbivores and pathogens by using constitutive (baseline) and inducible (change in defense after an attack) defenses. Inducibility has long been predicted to trade off with constitutive defense, reflecting the economic use of resources. However, empirical evidence for such tradeoffs is variable, and we still lack understanding about when and where defense trade-offs occur. We tested for tradeoffs between constitutive and induced defenses in natural populations of three species of long-lived pines (Pinus balfouriana, P. flexilis, P. longaeva) that differ greatly in constitutive defense and resistance to mountain pine beetle (MPB, Dendroctonus ponderosae). We also assessed how climate influenced constitutive and inducible defenses. At seven high-elevation sites in the western U.S., we simulated MPB attack to induce defenses and measured concentrations of terpene-based phloem defenses on days 0, 15, and 30. Constitutive and induced defenses did not trade off among or within species. Simulated MPB attack induced large increases in defense concentrations in all species independent of constitutive levels. MPB and its symbiotic fungi typically kill trees and thus could be selective forces maintaining strong inducibility within and among species. The contrasting constitutive concentrations in these species could be driven by the adaptation for specializing in harsh, high-elevation environments (e.g., P. balfouriana and P. longaeva) or by competition (e.g., P. flexilis), though these hypotheses have not been empirically examined. Climate influenced defenses, with the greatest concentrations of constitutive and induced defenses occurring at the coldest and driest sites. The interactions between climate and defenses have implications for these species under climate change.
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5
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Soderberg DN, Bentz BJ, Runyon JB, Hood SM, Mock KE. Chemical defense strategies, induction timing, growth, and trade‐offs in
Pinus aristata
and
Pinus flexilis. Ecosphere 2022. [DOI: 10.1002/ecs2.4183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- David N. Soderberg
- Wildland Resources Department Utah State University Logan Utah USA
- Ecology Center Utah State University Logan Utah USA
| | - Barbara J. Bentz
- USDA Forest Service, Rocky Mountain Research Station Logan Utah USA
| | - Justin B. Runyon
- USDA Forest Service, Rocky Mountain Research Station Bozeman Montana USA
| | - Sharon M. Hood
- USDA Forest Service, Rocky Mountain Research Station Missoula Montana USA
| | - Karen E. Mock
- Wildland Resources Department Utah State University Logan Utah USA
- Ecology Center Utah State University Logan Utah USA
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6
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Chiu CC, Bohlmann J. Mountain Pine Beetle Epidemic: An Interplay of Terpenoids in Host Defense and Insect Pheromones. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:475-494. [PMID: 35130442 DOI: 10.1146/annurev-arplant-070921-103617] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The mountain pine beetle epidemic has highlighted the complex interactions of bark beetles with conifer host defenses. In these interactions, oleoresin terpenoids and volatiles, produced and released by the host tree, can be both harmful and beneficial to the beetle's success in colonizing a tree and completing its life cycle. The insect spends almost its entire life, from egg to adult, within the bark and phloem of a pine host, exposed to large quantities of complex mixtures of oleoresin terpenoids. Conifer oleoresin comprises mostly monoterpenes and diterpene resin acids as well as many different sesquiterpenes. It functions as a major chemical and physical defense system. However, the insect has evolved host colonization behavior and enzymes for terpenoid metabolism and detoxification that allow it to overcome some of the terpenoid defenses and, importantly, to co-opt pine monoterpenes as cues for host search and as a precursor for its own pheromone system. The insect-associated microbiome also plays a role in the metabolism of conifer terpenoids.
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Affiliation(s)
- Christine C Chiu
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada;
| | - Joerg Bohlmann
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada;
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Liu J, Xia S, Zeng D, Liu C, Li Y, Yang W, Yang B, Zhang J, Slik F, Lindenmayer DB. Age and spatial distribution of the world's oldest trees. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36. [PMID: 35288993 DOI: 10.1111/cobi.13907] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 02/12/2022] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
Extremely old trees have important roles in providing insights about historical climatic events and supporting cultural values. Yet there has been limited work on the global distribution and conservation of these trees. We extracted information on 197,855 tree cores at 4,854 sites, and combined it with other tree age data from a further 156 sites, to determine the age of the world's oldest trees and quantify the factors influencing their global distribution. We found that extremely old trees >1,000 years are rare. Among 30 individual trees that exceeded 2,000 years old, 27 occurred in high mountains. Our model suggests that many of the existing oldest trees occur in high-elevation, cold and arid mountains with limited human disturbance. This pattern is markedly different from that of the tallest trees, which are more likely to occur in more mesic and productive locations. Global warming and expansion of human activities may induce rapid population declines of extremely old trees. New strategies, including targeted establishment of conservation reserves in remote regions, especially those in western Table 1 parts of China and USA, are required to protect these trees. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jiajia Liu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai, China
| | - Shangwen Xia
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, China
| | - Di Zeng
- MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Cong Liu
- Department of Organismic and Evolutional Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Yingjun Li
- Research Centre for Scientific Development in Fenhe River Valley, Taiyuan Normal University, Jinzhong, China
| | - Wenjing Yang
- Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
| | - Bao Yang
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
- CAS Centre for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100101, China
- Qinghai Research Centre of Qilian Mountain National Park, Academy of Plateau Science and Sustainability and Qinghai Normal University, Xining, 810008, China
| | - Jian Zhang
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Ferry Slik
- Environmental and Life Sciences Department, Faculty of Science, Universiti Brunei Darussalam, Gadong, Brunei Darussalam
| | - David B Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, Australia
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Liu X, Ziaco E, Biondi F. Water-Use Efficiency of Co-occurring Sky-Island Pine Species in the North American Great Basin. FRONTIERS IN PLANT SCIENCE 2021; 12:787297. [PMID: 34925427 PMCID: PMC8678526 DOI: 10.3389/fpls.2021.787297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/02/2021] [Indexed: 06/14/2023]
Abstract
Water-use efficiency (WUE), weighing the balance between plant transpiration and growth, is a key characteristic of ecosystem functioning and a component of tree drought resistance. Seasonal dynamics of tree-level WUE and its connections with drought variability have not been previously explored in sky-island montane forests. We investigated whole-tree transpiration and stem growth of bristlecone (Pinus longaeva) and limber pine (Pinus flexilis) within a high-elevation stand in central-eastern Nevada, United States, using sub-hourly measurements over 5 years (2013-2017). A moderate drought was generally observed early in the growing season, whereas interannual variability of summer rains determined drought levels between years, i.e., reducing drought stress in 2013-2014 while enhancing it in 2015-2017. Transpiration and basal area increment (BAI) of both pines were coupled throughout June-July, resulting in a high but relatively constant early season WUE. In contrast, both pines showed high interannual plasticity in late-season WUE, with a predominant role of stem growth in driving WUE. Overall, bristlecone pine was characterized by a lower WUE compared to limber pine. Dry or wet episodes in the late growing season overrode species differences. Our results suggested thresholds of vapor pressure deficit and soil moisture that would lead to opposite responses of WUE to late-season dry or wet conditions. These findings provide novel insights and clarify potential mechanisms modulating tree-level WUE in sky-island ecosystems of semi-arid regions, thereby helping land managers to design appropriate science-based strategies and reduce uncertainties associated with the impact of future climatic changes.
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Affiliation(s)
- Xinsheng Liu
- School of Geography and Tourism, Anhui Normal University, Wuhu, China
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, United States
- College of Tourism and Geography, Jiujiang University, Jiujiang, China
| | - Emanuele Ziaco
- Department of Ecology and Genetics, Plant Ecology and Evolution, University of Uppsala, Uppsala, Sweden
| | - Franco Biondi
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, United States
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Howe M, Carroll A, Gratton C, Raffa KF. Climate-induced outbreaks in high-elevation pines are driven primarily by immigration of bark beetles from historical hosts. GLOBAL CHANGE BIOLOGY 2021; 27:5786-5805. [PMID: 34428326 DOI: 10.1111/gcb.15861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/19/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Warming temperatures are allowing native insect herbivores to expand into regions that previously exceeded their thermal tolerance, encounter new host species, and pose significant threats to native communities. However, the dynamics of these expansions remain poorly understood, particularly in the extent to which outbreaks remain reliant on emigration from historical hosts or are driven by local reproduction within novel hosts in the expanded range. We tested these non-mutually exclusive hypotheses using spatially explicit data on mountain pine beetle (Dendroctonus ponderosae), which historically undergoes intermittent outbreaks in low-elevation lodgepole pine (Pinus contorta), but is now causing severe mortality in a high-elevation endangered species, whitebark pine (Pinus albicaulis). We compiled data from 2000 to 2019 across British Columbia, Canada, at 1-km2 resolution, and analyzed spatiotemporal patterns of beetle infestations, lodgepole pine distributions, expansion into habitats dominated by whitebark pine, and the likelihood of future outbreaks in all pine communities under simulated conditions. Overall, we found strong support for the hypothesis of emigration from the historical host species continuing to be a major driver of outbreaks in the more recently accessed host. First, beetle population pressure was consistently the best predictor of infestation severity in both lodgepole and whitebark pine, and appeared to be mostly unidirectional from lodgepole to whitebark pine. Second, infestations in lodgepole pine were of a longer duration than those in whitebark pine, which appeared too brief to sustain transitions from endemic to eruptive dynamics. Furthermore, resource depletion appears to drive emigration from lodgepole pine, whereas in whitebark pine drought appears to favor establishment of immigrants although bioclimatic factors and stand structure preclude self-sustaining outbreaks. Finally, we project that most pine in British Columbia will be at risk in the event of a new major outbreak. We describe implications for conserving and protecting whitebark pine and to other climate-driven range expansions.
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Affiliation(s)
- Michael Howe
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Allan Carroll
- Department of Forest & Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Claudio Gratton
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kenneth F Raffa
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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10
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Zhang P, Luan M, Li X, Lian Z, Zhao X. The distribution of soil fungal communities along an altitudinal gradient in an alpine meadow. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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11
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Soderberg DN, Kyre B, Bonello P, Bentz BJ. Lignin concentrations in phloem and outer bark are not associated with resistance to mountain pine beetle among high elevation pines. PLoS One 2021; 16:e0250395. [PMID: 34555045 PMCID: PMC8460017 DOI: 10.1371/journal.pone.0250395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 08/10/2021] [Indexed: 12/02/2022] Open
Abstract
A key component in understanding plant-insect interactions is the nature of host defenses. Research on defense traits among Pinus species has focused on specialized metabolites and axial resin ducts, but the role of lignin in defense within diverse systems is unclear. We investigated lignin levels in the outer bark and phloem of P. longaeva, P. balfouriana, and P. flexilis; tree species growing at high elevations in the western United States known to differ in susceptibility to mountain pine beetle (Dendroctonus ponderosae; MPB). Pinus longaeva and P. balfouriana are attacked by MPB less frequently than P. flexilis, and MPB brood production in P. longaeva is limited. Because greater lignification of feeding tissues has been shown to provide defense against bark beetles in related genera, such as Picea, we hypothesized that P. longaeva and P. balfouriana would have greater lignin concentrations than P. flexilis. Contrary to expectations, we found that the more MPB-susceptible P. flexilis had greater phloem lignin levels than the less susceptible P. longaeva and P. balfouriana. No differences in outer bark lignin levels among the species were found. We conclude that lignification in Pinus phloem and outer bark is likely not adaptive as a physical defense against MPB.
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Affiliation(s)
- David N. Soderberg
- Wildland Resources Department, Utah State University, Logan, Utah, United States of America
- Ecology Center, Utah State University, Logan, Utah, United States of America
| | - Bethany Kyre
- Department of Entomology, University of Kentucky, Lexington, KY, United States of America
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, Columbus, OH, United States of America
| | - Barbara J. Bentz
- Wildland Resources Department, Utah State University, Logan, Utah, United States of America
- US Forest Service, Rocky Mountain Research Station, Logan, Utah, United States of America
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12
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Ullah A, Klutsch JG, Erbilgin N. Production of complementary defense metabolites reflects a co-evolutionary arms race between a host plant and a mutualistic bark beetle-fungal complex. PLANT, CELL & ENVIRONMENT 2021; 44:3064-3077. [PMID: 34008191 DOI: 10.1111/pce.14100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Intra-specific variation in conifers has been extensively studied with respect to defense against herbivores and pathogens. While studies have shown the ability of individual or specific mixtures of compounds to influence insects and microbes, research testing biologically relevant mixtures of defense compounds reflecting intra-specific variation amongst tree populations to enemy complexes is needed. We characterized the variations in lodgepole pine monoterpenes from a progeny trial in western Canada and grouped trees in four clusters using their monoterpene profiles. We then selected 11 representative families across four clusters and amended their entire monoterpene profiles (with the exception of β-phellandrene) in media to determine how representative families affect the performance of the mountain pine beetle or its fungal symbiont. We placed adult beetles or inoculated fungus on the amended media and measured beetle performance and fungal growth as a proxy to host suitability. We found that different clusters or families differentially influenced beetle or fungal responses. However, monoterpene profiles of trees suitable to the beetle or the fungus were dissimilar. These outcomes reflect a co-evolutionary arms-race between the host and the bark beetle-fungus complex, which has resulted in the production of complementary defense metabolites among different pine populations to enhance tree survival.
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Affiliation(s)
- Aziz Ullah
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jennifer G Klutsch
- 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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13
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Piovesan G, Biondi F. On tree longevity. THE NEW PHYTOLOGIST 2021; 231:1318-1337. [PMID: 33305422 DOI: 10.1111/nph.17148] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 11/25/2020] [Indexed: 05/03/2023]
Abstract
Large, majestic trees are iconic symbols of great age among living organisms. Published evidence suggests that trees do not die because of genetically programmed senescence in their meristems, but rather are killed by an external agent or a disturbance event. Long tree lifespans are therefore allowed by specific combinations of life history traits within realized niches that support resistance to, or avoidance of, extrinsic mortality. Another requirement for trees to achieve their maximum longevity is either sustained growth over extended periods of time or at least the capacity to increase their growth rates when conditions allow it. The growth plasticity and modularity of trees can then be viewed as an evolutionary advantage that allows them to survive and reproduce for centuries and millennia. As more and more scientific information is systematically collected on tree ages under various ecological settings, it is becoming clear that tree longevity is a key trait for global syntheses of life history strategies, especially in connection with disturbance regimes and their possible future modifications. In addition, we challenge the long-held notion that shade-tolerant, late-successional species have longer lifespans than early-successional species by pointing out that tree species with extreme longevity do not fit this paradigm. Identifying extremely old trees is therefore the groundwork not only for protecting and/or restoring entire landscapes, but also to revisit and update classic ecological theories that shape our understanding of environmental change.
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Affiliation(s)
- Gianluca Piovesan
- Dendrology Lab, Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, Viterbo, 01100, Italy
| | - Franco Biondi
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, 89557, USA
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14
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Bentz BJ, Hansen EM, Vandygriff JC, Stephens SS, Soderberg D. Rocky Mountain Bristlecone Pine (Pinus aristata) is a Confirmed Host to Mountain Pine Beetle (Dendroctonus ponderosae). WEST N AM NATURALIST 2021. [DOI: 10.3398/064.081.0102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | | | | | | | - David Soderberg
- USDA Forest Service, Rocky Mountain Research Station, Logan, UT
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15
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Liu X, Biondi F. Transpiration drivers of high-elevation five-needle pines (Pinus longaeva and Pinus flexilis) in sky-island ecosystems of the North American Great Basin. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 739:139861. [PMID: 32544678 DOI: 10.1016/j.scitotenv.2020.139861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/24/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
We investigated the interaction between soil water supply and atmospheric evaporative demand for driving the seasonal pattern of transpiration in sky-island high-elevation forest ecosystems. Sap flow measurements were collected at 10-minute intervals for five consecutive years (2013-2017) on two co-occurring subalpine conifers, i.e. limber pine (Pinus flexilis) and bristlecone pine (Pinus longaeva). Our study site is part of the Nevada Climate-ecohydrological Assessment Network (NevCAN), and is located at 3355 m a.s.l. within an undisturbed mixed-conifer stand. We found that seasonal changes in soil moisture regulated transpiration sensitivity to atmospheric conditions. Sap flow density was mainly limited by evaporative demands under non-water limiting conditions, but was influenced only by soil moisture when water availability decreased. Daily sap flow density increased with radiation and soil moisture in June and July when soil moisture was generally above 10%, but correlated only with soil moisture in August and September when soil drought occurred. Sap flow sensitivity to vapor pressure deficit and solar radiation was therefore reduced under decreasing soil moisture conditions. Transpiration peaked in mid-to-late June during both dry and wet years, with a lower peak in late summer during wet years. Normalized mean daily canopy conductance of both species declined with decreasing soil moisture (i.e., increasing soil drought). Severe soil drying (i.e., soil moisture <7% at 20 cm depth), which was rarely detected in wet summers (2013-2014) but occurred more frequently in dry summers (2015-2017), induced a minimum in crown conductance with unchanged low-level sap flow, which might potentially trigger hydraulic failure. The minimum sap flow level under severe soil drought was higher for limber pine than bristlecone pine, possibly because of wider tracheids in limber compared to bristlecone pine. Our findings provide insights into physiological mechanisms of drought-induced stress for iconic sky-island five-needle pines located at high elevation in xeric environments.
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Affiliation(s)
- Xinsheng Liu
- College of Tourism and Geography, Jiujiang University, East Qianjin Road No. 551, Jiujiang 332005, China; DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV 89557, USA
| | - Franco Biondi
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV 89557, USA.
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Vázquez-González C, Zas R, Erbilgin N, Ferrenberg S, Rozas V, Sampedro L. Resin ducts as resistance traits in conifers: linking dendrochronology and resin-based defences. TREE PHYSIOLOGY 2020; 40:1313-1326. [PMID: 32478382 DOI: 10.1093/treephys/tpaa064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 05/26/2020] [Indexed: 05/20/2023]
Abstract
Conifers have evolved different chemical and anatomical defences against a wide range of antagonists. Resin ducts produce, store and translocate oleoresin, a complex terpenoid mixture that acts as both a physical and a chemical defence. Although resin duct characteristics (e.g., number, density, area) have been positively related to biotic resistance in several conifer species, the literature reporting this association remains inconclusive. Axial resin ducts recorded in annual growth rings are an archive of annual defensive investment in trees. This whole-life record of defence investment can be analysed using standard dendrochronological procedures, which allows us to assess interannual variability and the effect of understudied drivers of phenotypic variation on resin-based defences. Understanding the sources of phenotypic variation in defences, such as genetic differentiation and environmental plasticity, is essential for assessing the adaptive potential of forest tree populations to resist pests under climate change. Here, we reviewed the evidence supporting the importance of resin ducts in conifer resistance, and summarized current knowledge about the sources of variation in resin duct production. We propose a standardized methodology to measure resin duct production by means of dendrochronological procedures. This approach will illuminate the roles of resin ducts in tree defence across species, while helping to fill pivotal knowledge gaps in plant defence theory, and leading to a robust understanding of the patterns of variation in resin-based defences throughout the tree's lifespan.
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Affiliation(s)
- Carla Vázquez-González
- Misión Biológica de Galicia, National Spanish Research Council (MBG-CSIC), Carballeira 8, Salcedo, Pontevedra 3614, Spain
| | - Rafael Zas
- Misión Biológica de Galicia, National Spanish Research Council (MBG-CSIC), Carballeira 8, Salcedo, Pontevedra 3614, Spain
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, T6G 2H1 Alberta, Canada
| | - Scott Ferrenberg
- Department of Biology, New Mexico State University, 1305 Frenger St., Las Cruces, 88001, NM, USA
| | - Vicente Rozas
- iuFOR-EiFAB, Campus Duques de Soria, Universidad de Valladolid, Soria 42004, Spain
- Laboratorio de Dendrocronología y Cambio Global, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Luis Sampedro
- Misión Biológica de Galicia, National Spanish Research Council (MBG-CSIC), Carballeira 8, Salcedo, Pontevedra 3614, Spain
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17
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Hood SM, Reed CC, Kane JM. Axial resin duct quantification in tree rings: A functional defense trait. MethodsX 2020; 7:101035. [PMID: 32939350 PMCID: PMC7476316 DOI: 10.1016/j.mex.2020.101035] [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: 05/28/2020] [Accepted: 08/15/2020] [Indexed: 11/24/2022] Open
Abstract
Resin ducts in the secondary xylem of tree rings are a measure of a tree's defense capacity from insects and pathogens. Because resin ducts are permanently embedded within the xylem, retrospective analysis can be performed to quantify changes in defense over time and determine factors that contribute to this change, such as climate and disturbance. Here, we provide methods on how to measure axial resin ducts in secondary xylem. These methods provide the necessary protocols for consistent quantification of xylem resin ducts and terminology, which will also allow easier cross-comparison among studies in the future. We describe:•Steps to prepare tree cores for resin duct measurements.•Procedure to obtain image and measure individual resin ducts.•Software code to compile duct measurements into a complete chronology with both standardized and unstandardized resin duct metrics for further analyses.
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Affiliation(s)
- Sharon M. Hood
- UDSA Forest Service, Rocky Mountain Research Station, Missoula, MT, United States
| | - Charlotte C. Reed
- UDSA Forest Service, Rocky Mountain Research Station, Missoula, MT, United States
| | - Jeffrey M. Kane
- Department of Forestry and Wildland Resources, Humboldt State University, Arcata, California, USA
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18
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López‐Goldar X, Zas R, Sampedro L. Resource availability drives microevolutionary patterns of plant defences. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13610] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xosé López‐Goldar
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
- Misión Biológica de Galicia Consejo Superior de Investigaciones Científicas Pontevedra Spain
| | - Rafael Zas
- Misión Biológica de Galicia Consejo Superior de Investigaciones Científicas Pontevedra Spain
| | - Luis Sampedro
- Misión Biológica de Galicia Consejo Superior de Investigaciones Científicas Pontevedra Spain
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19
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Runyon JB, Gray CA, Jenkins MJ. Volatiles of High-Elevation Five-Needle Pines: Chemical Signatures through Ratios and Insight into Insect and Pathogen Resistance. J Chem Ecol 2020; 46:264-274. [PMID: 31974726 DOI: 10.1007/s10886-020-01150-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/07/2020] [Accepted: 01/16/2020] [Indexed: 01/11/2023]
Abstract
High-elevation five-needle pine trees are a group of Pinus species in the subgenus Strobus that occur at the edges of plant growth near the alpine tree line. These species are ecologically very important and are also threatened by climate-driven insect outbreaks and an exotic pathogen. Volatile organic compounds (VOCs) play central roles in the environmental adaptation of plants and in their defense against insects and pathogens. For example, the VOCs emitted by some high-elevation five-needle pine species attract female, tree-killing mountain pine beetles (MPB, Dendroctonus ponderosae) in the pioneering phase whereas VOCs from other species strongly repel this foremost herbivore, but the mechanism is unknown. We collected and compared headspace VOCs from foliage of eight species of high-elevation five-needle pines in Europe and North America. Overall, VOCs differed quantitatively among species with few qualitative differences. Despite species emitting essentially the same compounds, Random Forest analysis correctly classified 117 of the 126 trees sampled by using VOCs and identified the most important compounds for species classification and for separating species resistant from those susceptible to MPB or white pine blister rust (Cronartium ribicola). These VOC 'fingerprints' resulted largely from species emitting distinctive ratios of compounds, rather than through presence of species-specific compounds. Importantly, these Pinus species vary greatly in resistance to the main herbivore (MPB) and pathogen (white pine blister rust) causing tree mortality. Thus, these findings provide insights and should guide research into understanding resistance and in developing tools to manage these important trees. For instance, studies into the functions of five-needle pine VOCs in defense against abiotic or biotic stressors should focus on blend ratios rather than on individual compounds.
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Affiliation(s)
- Justin B Runyon
- USDA Forest Service, Rocky Mountain Research Station, Forestry Sciences Laboratory, 1648 S 7th Ave., Bozeman, MT, 59717, USA.
| | - Curtis A Gray
- Department of Wildland Resources, Utah State University, 5230 Old Main Hill, Logan, UT, 84322, USA
| | - Michael J Jenkins
- Department of Wildland Resources, Utah State University, 5230 Old Main Hill, Logan, UT, 84322, USA
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20
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Mason CJ, Keefover-Ring K, Villari C, Klutsch JG, Cook S, Bonello P, Erbilgin N, Raffa KF, Townsend PA. Anatomical defences against bark beetles relate to degree of historical exposure between species and are allocated independently of chemical defences within trees. PLANT, CELL & ENVIRONMENT 2019; 42:633-646. [PMID: 30474119 DOI: 10.1111/pce.13449] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 06/09/2023]
Abstract
Conifers possess chemical and anatomical defences against tree-killing bark beetles that feed in their phloem. Resins accumulating at attack sites can delay and entomb beetles while toxins reach lethal levels. Trees with high concentrations of metabolites active against bark beetle-microbial complexes, and more extensive resin ducts, achieve greater survival. It is unknown if and how conifers integrate chemical and anatomical components of defence or how these capabilities vary with historical exposure. We compared linkages between phloem chemistry and tree ring anatomy of two mountain pine beetle hosts. Lodgepole pine, a mid-elevation species, has had extensive, continual contact with this herbivore, whereas high-elevation whitebark pines have historically had intermittent exposure that is increasing with warming climate. Lodgepole pine had more and larger resin ducts. In both species, anatomical defences were positively related to tree growth and nutrients. Within-tree constitutive and induced concentrations of compounds bioactive against bark beetles and symbionts were largely unrelated to resin duct abundance and size. Fewer anatomical defences in the semi-naïve compared with the continually exposed host concurs with directional differences in chemical defences. Partially uncoupling chemical and morphological antiherbivore traits may enable trees to confront beetles with more diverse defence permutations that interact to resist attack.
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Affiliation(s)
- Charles J Mason
- Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania
| | - Ken Keefover-Ring
- Departments of Botany and Geography, University of Wisconsin-Madison, Madison, Wisconsin
| | - Caterina Villari
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio
| | - Jennifer G Klutsch
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Stephen Cook
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Kenneth F Raffa
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Philip A Townsend
- Departments of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin
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21
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Felhofer M, Prats-Mateu B, Bock P, Gierlinger N. Antifungal stilbene impregnation: transport and distribution on the micron-level. TREE PHYSIOLOGY 2018; 38:1526-1537. [PMID: 29992254 PMCID: PMC6198867 DOI: 10.1093/treephys/tpy073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/17/2018] [Accepted: 06/03/2018] [Indexed: 05/04/2023]
Abstract
The transition from the living water-transporting sapwood to heartwood involves in many tree species impregnation with extractives. These differ in amount and composition, and enhance resistance against bacteria, insects or fungi. To understand the synthesis, transport and impregnation processes new insights into the biochemical processes are needed by in-situ methods. Here we show the extractive distribution in pine (Pinus sylvestris) microsections with a high lateral resolution sampled in a non-destructive manner using Confocal Raman Microscopy. Integrating marker bands of stilbenes and lipids enables to clearly track the rapid change from sapwood to heartwood within one tree ring. The higher impregnation of the cell corner, compound middle lamella, the S3 layer and pits reveals the optimization of decay resistance on the micron-level. Furthermore, deposits with changing chemical composition are elucidated in the rays and lumen of the tracheids. The spectral signature of these deposits shows the co-location of lipids and pinosylvins with changing ratios from the living to the dead tissue. The results demonstrate that the extractive impregnation on the micro- and nano-level is optimized by a symbiotic relationship of lipids and pinosylvins to enhance the tree's resistance and lifetime.
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Affiliation(s)
- Martin Felhofer
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Muthgasse, Vienna, Austria
| | - Batirtze Prats-Mateu
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Muthgasse, Vienna, Austria
| | - Peter Bock
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Muthgasse, Vienna, Austria
| | - Notburga Gierlinger
- Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Muthgasse, Vienna, Austria
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22
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Klutsch JG, Erbilgin N. Dwarf mistletoe infection in jack pine alters growth-defense relationships. TREE PHYSIOLOGY 2018; 38:1538-1547. [PMID: 30137634 DOI: 10.1093/treephys/tpy090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
Trees utilize a combination of chemical and anatomical defenses against a myriad of attacking organisms. However, persistent pathogen infection that alters resource acquisition may impact growth and defense relationships, which could have consequences for tree resistance. We characterized systemic chemical and anatomical changes in jack pine (Pinus banksiana) in response to infection by the parasitic plant dwarf mistletoe (Arceuthobium americanum) and identified how the growth-defense relationship is altered due to infection severity. Our study found that the growth and defense relationship in jack pine was altered due to infection and that chemical defenses in the phloem received a relatively higher priority than radial growth and anatomical defenses. Chemical defenses in the phloem had a non-linear relationship with infection severity with increasing concentrations of monoterpenes in trees with moderate infection and decreasing concentrations at high infection. In contrast, both radial growth and vertical resin duct production decreased with increasing infection severity. While constitutive resin duct counts and many monoterpene compound concentrations were positively correlated, this relationship was not maintained in infected trees. Furthermore, radial growth and basal area increment was positively correlated with resin duct production and monoterpene concentration in non-infected trees but had fewer relationships in severely infected trees. We conclude that while both chemical and anatomical defenses may be used as indicators for potential resistance to biotic stress in pines, changes in resource allocation patterns between these defenses after infection will likely have consequences on tree resistance to subsequent biotic attacks.
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Affiliation(s)
- Jennifer G Klutsch
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
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23
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Eidson EL, Mock KE, Bentz BJ. Low offspring survival in mountain pine beetle infesting the resistant Great Basin bristlecone pine supports the preference-performance hypothesis. PLoS One 2018; 13:e0196732. [PMID: 29715269 PMCID: PMC5929522 DOI: 10.1371/journal.pone.0196732] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/18/2018] [Indexed: 12/11/2022] Open
Abstract
The preference-performance hypothesis states that ovipositing phytophagous insects will select host plants that are well-suited for their offspring and avoid host plants that do not support offspring performance (survival, development and fitness). The mountain pine beetle (Dendroctonus ponderosae), a native insect herbivore in western North America, can successfully attack and reproduce in most species of Pinus throughout its native range. However, mountain pine beetles avoid attacking Great Basin bristlecone pine (Pinus longaeva), despite recent climate-driven increases in mountain pine beetle populations at the high elevations where Great Basin bristlecone pine grows. Low preference for a potential host plant species may not persist if the plant supports favorable insect offspring performance, and Great Basin bristlecone pine suitability for mountain pine beetle offspring performance is unclear. We infested cut bolts of Great Basin bristlecone pine and two susceptible host tree species, limber (P. flexilis) and lodgepole (P. contorta) pines with adult mountain pine beetles and compared offspring performance. To investigate the potential for variation in offspring performance among mountain pine beetles from different areas, we tested beetles from geographically-separated populations within and outside the current range of Great Basin bristlecone pine. Although mountain pine beetles constructed galleries and laid viable eggs in all three tree species, extremely few offspring emerged from Great Basin bristlecone pine, regardless of the beetle population. Our observed low offspring performance in Great Basin bristlecone pine corresponds with previously documented low mountain pine beetle attack preference. A low preference-low performance relationship suggests that Great Basin bristlecone pine resistance to mountain pine beetle is likely to be retained through climate-driven high-elevation mountain pine beetle outbreaks.
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Affiliation(s)
- Erika L. Eidson
- Wildland Resources Department, Utah State University, Logan, Utah, United States of America
- * E-mail:
| | - Karen E. Mock
- Wildland Resources Department, Utah State University, Logan, Utah, United States of America
- Ecology Center, Utah State University, Logan, Utah, United States of America
| | - Barbara J. Bentz
- USDA Forest Service Rocky Mountain Research Station, Logan, Utah, United States of America
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24
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Davis TS, Horne FB, Yetter JC, Stewart JE. Engelmann Spruce Chemotypes in Colorado and their Effects on Symbiotic Fungi Associated with the North American Spruce Beetle. J Chem Ecol 2018; 44:601-610. [DOI: 10.1007/s10886-018-0961-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/04/2018] [Accepted: 04/13/2018] [Indexed: 02/01/2023]
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25
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Rapid neo-sex chromosome evolution and incipient speciation in a major forest pest. Nat Commun 2017; 8:1593. [PMID: 29150608 PMCID: PMC5693900 DOI: 10.1038/s41467-017-01761-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 10/12/2017] [Indexed: 12/30/2022] Open
Abstract
Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations. This striking progression of reproductive isolation is coupled with extensive gene specialization, natural selection, and elevated genetic differentiation on both sex chromosomes. Closely related populations isolated by hybrid male sterility also show fixation of alternative neo-Y haplotypes that differ in structure and male-specific gene content. Our results suggest that neo-sex chromosome evolution can drive rapid functional divergence between closely related populations irrespective of ecological drivers of divergence. The evolution of new sex chromosomes potentially generates reproductive isolation. Here, Bracewell et al. combine crossing experiments with population and functional genomics to characterize neo-sex chromosome evolution and incipient speciation in the mountain pine beetle, Dendroctonus ponderosae.
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26
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Dowle EJ, Bracewell RR, Pfrender ME, Mock KE, Bentz BJ, Ragland GJ. Reproductive isolation and environmental adaptation shape the phylogeography of mountain pine beetle (Dendroctonus ponderosae). Mol Ecol 2017; 26:6071-6084. [PMID: 29116665 DOI: 10.1111/mec.14342] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 05/12/2017] [Accepted: 08/05/2017] [Indexed: 12/23/2022]
Abstract
Chromosomal rearrangement can be an important mechanism driving population differentiation and incipient speciation. In the mountain pine beetle (MPB, Dendroctonus ponderosae), deletions on the Y chromosome that are polymorphic among populations are associated with reproductive incompatibility. Here, we used RAD sequencing across the entire MPB range in western North America to reveal the extent of the phylogeographic differences between Y haplotypes compared to autosomal and X-linked loci. Clustering and geneflow analyses revealed three distinct Y haplogroups geographically positioned within and on either side of the Great Basin Desert. Despite close geographic proximity between populations on the boundaries of each Y haplogroup, there was extremely low Y haplogroup mixing among populations, and gene flow on the autosomes was reduced across Y haplogroup boundaries. These results are consistent with a previous study suggesting that independent degradation of a recently evolved neo-Y chromosome in previously isolated populations causes male sterility or inviability among Y haplotype lineages. Phylogeographic results supported historic contraction of MPB into three separate Pleistocene glacial refugia followed by postglacial range expansion and secondary contact. Distinct sets of SNPs were statistically associated with environmental data among the most genetically distinct sets of geographic populations. This finding suggests that the process of adaptation to local climatic conditions is influenced by population genetic structure, with evidence for largely independent evolution in the most genetically isolated Y haplogroup.
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Affiliation(s)
- Eddy J Dowle
- Department of Entomology, Kansas State University, Manhattan, KS, USA.,Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | - Ryan R Bracewell
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Michael E Pfrender
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Karen E Mock
- Department of Wildland Resources, Utah State University, Logan, UT, USA
| | - Barbara J Bentz
- Department of Wildland Resources, Utah State University, Logan, UT, USA.,USDA Forest Service, Rocky Mountain Research Station, Logan, UT, USA
| | - Gregory J Ragland
- Department of Entomology, Kansas State University, Manhattan, KS, USA.,Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
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27
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Ferrenberg S, Langenhan JM, Loskot SA, Rozal LM, Mitton JB. Resin monoterpene defenses decline within three widespread species of pine (Pinus) along a 1530-m elevational gradient. Ecosphere 2017. [DOI: 10.1002/ecs2.1975] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- Scott Ferrenberg
- Department of Biology; New Mexico State University; Las Cruces New Mexico 88003 USA
| | | | - Steven A. Loskot
- Department of Chemistry; Seattle University; Seattle Washington 98122 USA
| | - Leonardo M. Rozal
- Department of Chemistry; Seattle University; Seattle Washington 98122 USA
| | - Jeffry B. Mitton
- Department of Ecology and Evolutionary Biology; University of Colorado; Boulder Colorado 80309 USA
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28
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Raffa KF, Mason CJ, Bonello P, Cook S, Erbilgin N, Keefover-Ring K, Klutsch JG, Villari C, Townsend PA. Defence syndromes in lodgepole - whitebark pine ecosystems relate to degree of historical exposure to mountain pine beetles. PLANT, CELL & ENVIRONMENT 2017; 40:1791-1806. [PMID: 28543133 DOI: 10.1111/pce.12985] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/21/2017] [Accepted: 04/28/2017] [Indexed: 06/07/2023]
Abstract
Warming climate is allowing tree-killing bark beetles to expand their ranges and access naïve and semi-naïve conifers. Conifers respond to attack using complex mixtures of chemical defences that can impede beetle success, but beetles exploit some compounds for host location and communication. Outcomes of changing relationships will depend on concentrations and compositions of multiple host compounds, which are largely unknown. We analysed constitutive and induced chemistries of Dendroctonus ponderosae's primary historical host, Pinus contorta, and Pinus albicaulis, a high-elevation species whose encounters with this beetle are transitioning from intermittent to continuous. We quantified multiple classes of terpenes, phenolics, carbohydrates and minerals. Pinus contorta had higher constitutive allocation to, and generally stronger inducibility of, compounds that resist these beetle-fungal complexes. Pinus albicaulis contained higher proportions of specific monoterpenes that enhance pheromone communication, and lower induction of pheromone inhibitors. Induced P. contorta increased insecticidal and fungicidal compounds simultaneously, whereas P. albicaulis responses against these agents were inverse. Induced terpene accumulation was accompanied by decreased non-structural carbohydrates, primarily sugars, in P. contorta, but not P. albicaulis, which contained primarily starches. These results show some host species with continuous exposure to bark beetles have more thoroughly integrated defence syndromes than less-continuously exposed host species.
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Affiliation(s)
- Kenneth F Raffa
- Department of Entomology, University of Wisconsin - Madison, Madison, WI, 53706, USA
| | - Charles J Mason
- Department of Entomology, University of Wisconsin - Madison, Madison, WI, 53706, USA
- Department of Entomology, Pennsylvania State University, State College, PA, 16802, USA
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210, USA
| | - Stephen Cook
- Department of Plant, Soil and Entomological Science, University of Idaho, Moscow, ID, 83844, USA
| | - Nadir Erbilgin
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Ken Keefover-Ring
- Departments of Botany and Geography, University of Wisconsin - Madison, Madison, WI, 53706, USA
| | - Jennifer G Klutsch
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Caterina Villari
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210, USA
- Warnell School of Forestry and Natural Resources, University of Georgia - Athens, Athens, GA, 30602, USA
| | - Philip A Townsend
- Department of Forest and Wildlife Ecology, University of Wisconsin - Madison, Madison, WI, 53706, USA
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29
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Contrasting Impacts of Climate and Competition on Large Sugar Pine Growth and Defense in a Fire-Excluded Forest of the Central Sierra Nevada. FORESTS 2017. [DOI: 10.3390/f8070244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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30
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Rosenberger DW, Venette RC, Maddox MP, Aukema BH. Colonization behaviors of mountain pine beetle on novel hosts: Implications for range expansion into northeastern North America. PLoS One 2017; 12:e0176269. [PMID: 28472047 PMCID: PMC5417433 DOI: 10.1371/journal.pone.0176269] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 04/07/2017] [Indexed: 01/08/2023] Open
Abstract
As climates change, thermal limits may no longer constrain some native herbivores within their historical ranges. The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a tree-killing bark beetle native to western North America that is currently expanding its range. Continued eastward expansion through the newly invaded and novel jack pine (Pinus banksiana Lamb.) trees of the Canadian boreal forest could result in exposure of several species of novel potential host pines common in northeastern North America to this oligophagous herbivore. Due to the tightly co-evolved relationship between mountain pine beetle and western pine hosts, in which the insect utilizes the defensive chemistry of the host to stimulate mass attacks, we hypothesized that lack of co-evolutionary association would affect the host attraction and acceptance behaviors of this insect among novel hosts, particularly those with little known historical association with an aggressive stem-infesting insect. We studied how beetle behavior differed among the various stages of colonization on newly cut logs of four novel potential pine host species; jack, red (P. resinosa Ait.), eastern white (P. strobus L.) and Scots (P. sylvestris L.) pines, as well as two historical hosts, ponderosa (P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm.) and lodgepole (P. contorta Dougl. var. latifolia Engelm.) pines. Overall, we found that beetle colonization behaviors at each stage in the colonization process differ between pine hosts, likely due to differing chemical and physical bark traits. Pines without co-evolved constitutive defenses against mountain pine beetle exhibited reduced amounts of defensive monoterpenoid chemicals; however, such patterns also reduced beetle attraction and colonization. Neither chemical nor physical defenses fully defended trees against the various stages of host procurement that can result in tree colonization and death.
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Affiliation(s)
- Derek W. Rosenberger
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America
- Department of Biological Sciences, Olivet Nazarene University, Bourbonnais, Illinois, United States of America
- * E-mail:
| | - Robert C. Venette
- United States Department of Agriculture—Forest Service, Northern Research Station, St. Paul, Minnesota, United States of America
| | - Mitchell P. Maddox
- Chemistry Department, Bethel University, St. Paul, Minnesota, United States of America
| | - Brian H. Aukema
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America
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Burke JL, Bohlmann J, Carroll AL. Consequences of distributional asymmetry in a warming environment: invasion of novel forests by the mountain pine beetle. Ecosphere 2017. [DOI: 10.1002/ecs2.1778] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Jordan Lewis Burke
- Department of Forest and Conservation Sciences Faculty of Forestry The University of British Columbia 2424 Main Mall Vancouver British Columbia V6T 1Z4 Canada
| | - Joerg Bohlmann
- Department of Forest and Conservation Sciences Faculty of Forestry The University of British Columbia 2424 Main Mall Vancouver British Columbia V6T 1Z4 Canada
- Michael Smith Laboratories The University of British Columbia 2185 East Mall Vancouver British Columbia V6T 1Z4 Canada
| | - Allan L. Carroll
- Department of Forest and Conservation Sciences Faculty of Forestry The University of British Columbia 2424 Main Mall Vancouver British Columbia V6T 1Z4 Canada
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Orlemann A, Flinders SH, Allphin L. The Discovery of Great Basin Bristlecone Pine, Pinus Longaeva, in the Tushar Mountains of the Fishlake National Forest in Central Utah, USA. WEST N AM NATURALIST 2017. [DOI: 10.3398/064.077.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Andrew Orlemann
- Beaver Ranger District, Fishlake National Forest, United States Department of Agriculture, Box E, Beaver, UT 84713
| | - Steven H. Flinders
- Beaver Ranger District, Fishlake National Forest, United States Department of Agriculture, Box E, Beaver, UT 84713
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