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Freedman MG, Long RW, Ramírez SR, Strauss SY. Evidence for Reductions in Physical and Chemical Plant Defense Traits in Island Flora. PLANTS (BASEL, SWITZERLAND) 2024; 13:1026. [PMID: 38611555 PMCID: PMC11013342 DOI: 10.3390/plants13071026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024]
Abstract
Reduced defense against large herbivores has been suggested to be part of the "island syndrome" in plants. However, empirical evidence for this pattern is mixed. In this paper, we present two studies that compare putative physical and chemical defense traits from plants on the California Channel Islands and nearby mainland based on sampling of both field and common garden plants. In the first study, we focus on five pairs of woody shrubs from three island and three mainland locations and find evidence for increased leaf area, decreased marginal leaf spines, and decreased concentrations of cyanogenic glycosides in island plants. We observed similar increases in leaf area and decreases in defense traits when comparing island and mainland genotypes grown together in botanic gardens, suggesting that trait differences are not solely driven by abiotic differences between island and mainland sites. In the second study, we conducted a common garden experiment with a perennial herb-Stachys bullata (Lamiaceae)-collected from two island and four mainland locations. Compared to their mainland relatives, island genotypes show highly reduced glandular trichomes and a nearly 100-fold reduction in mono- and sesquiterpene compounds from leaf surfaces. Island genotypes also had significantly higher specific leaf area, somewhat lower rates of gas exchange, and greater aboveground biomass than mainland genotypes across two years of study, potentially reflecting a broader shift in growth habit. Together, our results provide evidence for reduced expression of putative defense traits in island plants, though these results may reflect adaptation to both biotic (i.e., the historical absence of large herbivores) and climatic conditions on islands.
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Affiliation(s)
- Micah G. Freedman
- Center for Population Biology, University of California, Davis, CA 95616, USA
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Randall W. Long
- Department of Biology, Lewis & Clark College, Portland, OR 97219, USA
| | - Santiago R. Ramírez
- Center for Population Biology, University of California, Davis, CA 95616, USA
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Sharon Y. Strauss
- Center for Population Biology, University of California, Davis, CA 95616, USA
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
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2
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Pei H, Wu Y, Wu W, Lyu L, Li W. A review of the types, functions and regulatory mechanisms of plant spines. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 341:112010. [PMID: 38309475 DOI: 10.1016/j.plantsci.2024.112010] [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: 09/12/2023] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
Over a long period of evolution, plants have developed self-protection mechanisms, such as leaving seeds, dropping leaves, growing thorns, producing specific substances or emitting special odors to repel insects. Although studies on the taxonomic characteristics, functions and application of spines in spiny plants have been reported in China and abroad, a systematic overview of plant spines is currently lacking. This study therefore identifies the characteristics and types of plant spines based on domestic and international research on plant spines to provide clear criteria or bases for determining the types of plant spines. In addition, the functions, regulatory mechanisms, and factors influencing the formation of spines and the prospects for their development and application are described and summarized. This study will help to improve the understanding of the types, functions and regulatory mechanisms of plant spines and provide new ideas for the genetic improvement of plants from spiny to nonspiny varieties.
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Affiliation(s)
- Huiyan Pei
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Yaqiong Wu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Qian Hu Hou Cun No. 1, Nanjing 210014, China.
| | - Wenlong Wu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Qian Hu Hou Cun No. 1, Nanjing 210014, China
| | - Lianfei Lyu
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Qian Hu Hou Cun No. 1, Nanjing 210014, China
| | - Weilin Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China.
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3
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Edwards CB, Ellner SP, Agrawal AA. Plant defense synergies and antagonisms affect performance of specialist herbivores of common milkweed. Ecology 2023; 104:e3915. [PMID: 36336890 DOI: 10.1002/ecy.3915] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/27/2022] [Indexed: 11/09/2022]
Abstract
As a general rule, plants defend against herbivores with multiple traits. The defense synergy hypothesis posits that some traits are more effective when co-expressed with others compared to their independent efficacy. However, this hypothesis has rarely been tested outside of phytochemical mixtures, and seldom under field conditions. We tested for synergies between multiple defense traits of common milkweed (Asclepias syriaca) by assaying the performance of two specialist chewing herbivores on plants in natural populations. We employed regression and a novel application of random forests to identify synergies and antagonisms between defense traits. We found the first direct empirical evidence for two previously hypothesized defense synergies in milkweed (latex by secondary metabolites, latex by trichomes) and identified numerous other potential synergies and antagonisms. Our strongest evidence for a defense synergy was between leaf mass per area and low nitrogen content; given that these "leaf economic" traits typically covary in milkweed, a defense synergy could reinforce their co-expression. We report that each of the plant defense traits showed context-dependent effects on herbivores, and increased trait expression could well be beneficial to herbivores for some ranges of observed expression. The novel methods and findings presented here complement more mechanistic approaches to the study of plant defense diversity and provide some of the best evidence to date that multiple classes of plant defense synergize in their impact on insects. Plant defense synergies against highly specialized herbivores, as shown here, are consistent with ongoing reciprocal evolution between these antagonists.
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Affiliation(s)
- Collin B Edwards
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.,Department of Biology, Tufts University, Medford, Massachusetts, USA
| | - Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
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4
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Biddick M. Scale-dependent trends in the investment of leaf domatia. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Theory predicts that plants invest in defences proportional to the value or amount of tissue at risk. Domatia-bearing plants house predatory arthropods that defend against insect and fungal attack. Though leaf domatia represent a direct investment in the defence of leaf tissues, it remains unknown whether domatia production scales with amount of tissue at risk. I investigated how domatia investment scales with leaf size in 20 species of trees and shrubs from the south-west Pacific. Large-leaved species produced more domatia than smaller leaved species. However, domatia production did not consistently scale with leaf area among individuals of the same species, illustrating that trends in domatia investment are scale-dependent. Overall results suggest the processes modulating the allocation of resources to defence at the interspecific level are distinct from those operating at the intraspecific level.
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Affiliation(s)
- Matthew Biddick
- Terrestrial Ecology Research Group, Technical University of Munich, Freising, Germany
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5
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Zhang Y, Zhao M, Zhu W, Shi C, Bao M, Zhang W. Nonglandular prickle formation is associated with development and secondary metabolism-related genes in Rosa multiflora. PHYSIOLOGIA PLANTARUM 2021; 173:1147-1162. [PMID: 34343346 DOI: 10.1111/ppl.13510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/17/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Roses are among the most economically important ornamental plants worldwide. But prickles on the stem and leaves cause difficulties for cultivation or inconveniences during harvest and transportation, thus are an undesirable horticultural character. However, little is known about the molecular mechanisms of prickle development. In this study, we sought to develop Rosa multiflora (in the family Rosaceae) as a model plant to study prickle formation. The morphology, structure, and ontogeny of prickles were characterized, and transcriptome analysis of prickly and prickleless R. multiflora genotypes was performed. Morphological observation and microscopic analyses revealed that prickles of R. multiflora were non-glandular prickles (NGPs) and their maturation went through five developmental stages, which was accompanied by the accumulation of secondary metabolites such as lignin and anthocyanins. Comparative transcriptome analysis identified key pathways and hub genes potentially involved in prickle formation. Interestingly, among the differentially expressed genes (DEGs), several notable development and secondary metabolism-related transcription factors (TFs) including NAC, TCP, MYB, homeobox, and WRKY were up-regulated in prickly internodes. KEGG enrichment analysis indicated that DEGs were enriched in the pathways related to biosynthesis of secondary metabolites, flavonoids, and phenylpropanoids in the prickly R. multiflora. Our study provides novel insights into the molecular network underlying the regulation of prickle morphogenesis in R. multiflora, and the identified candidates might be applied to the genetic improvement of roses.
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Affiliation(s)
- Yu Zhang
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (pilot run), Ministry of Agriculture, Wuhan, China
| | - Mingjie Zhao
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (pilot run), Ministry of Agriculture, Wuhan, China
| | - Wan Zhu
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (pilot run), Ministry of Agriculture, Wuhan, China
| | - Chunmei Shi
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Manzhu Bao
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (pilot run), Ministry of Agriculture, Wuhan, China
| | - Wei Zhang
- Key Laboratory of horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Urban Agriculture in Central China (pilot run), Ministry of Agriculture, Wuhan, China
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6
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Sobuj N, Nissinen K, Virjamo V, Salonen A, Sivadasan U, Randriamanana T, Ikonen VP, Kilpeläinen A, Julkunen-Tiitto R, Nybakken L, Mehtätalo L, Peltola H. Accumulation of phenolics and growth of dioecious Populus tremula (L.) seedlings over three growing seasons under elevated temperature and UVB radiation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 165:114-122. [PMID: 34034157 DOI: 10.1016/j.plaphy.2021.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/08/2021] [Indexed: 06/12/2023]
Abstract
Accumulation of secondary metabolites may exhibit developmentally regulated variation in different plant organs. Moreover, prevailing environmental conditions may interact with development-related variations in plant traits. In this study, we examined developmentally regulated variation in phenolic accumulation in the twigs of dioecious Populus tremula (L.) and how the effects of elevated temperature and ultraviolet B (UVB) radiation on growth and phenolics accumulation varied as the plants get older. In an open-field experiment, six female and six male genotypes were exposed to single and combined elevated temperature and UVB radiation treatments for three consecutive growing seasons. The concentrations of low molecular weight phenolics and condensed tannins did not show age-dependent variation in the twigs. In temperature-treated plants, diameter growth rate decreased, and concentration of condensed tannins increased as plants aged; there were no cumulative effects of elevated UVB radiation on growth and phenolic accumulation. Females maintained a higher concentration of low molecular weight phenolics throughout the experimental period; however, growth and phenolic concentration did not vary over time in females and males. Our results suggest that phenolic accumulation in perennial plants may not necessarily always exhibit age-dependent variation and the effects of elevated temperature on growth and phenolic may diminish as plants get older.
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Affiliation(s)
- Norul Sobuj
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland.
| | - Katri Nissinen
- School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Virpi Virjamo
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland; School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Anneli Salonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Unnikrishnan Sivadasan
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Tendry Randriamanana
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Veli-Pekka Ikonen
- School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Antti Kilpeläinen
- School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Riitta Julkunen-Tiitto
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101, Joensuu, Finland
| | - Line Nybakken
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Lauri Mehtätalo
- School of Computing, University of Eastern Finland, 80101, Joensuu, Finland
| | - Heli Peltola
- School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland
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7
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RNA-Seq Analysis of Prickled and Prickle-Free Epidermis Provides Insight into the Genetics of Prickle Development in Red Raspberry (Rubus ideaus L.). AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10121904] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Red raspberry (Rubus idaeus L.) is a globally commercialized specialty crop with growing demand worldwide. The presence of prickles on the stems, petioles and undersides of the leaves complicates both the field management and harvesting of raspberries. An RNA sequencing analysis was used to identify differentially expressed genes in the epidermal tissue of prickled “Caroline” and prickle-free “Joan J.” and their segregating progeny. Expression patterns of differentially expressed genes (DEGs) in prickle-free plants revealed the downregulation of some vital development-related transcription factors (TFs), including a MIXTA-like R2R3-MYB family member; MADS-box; APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) and NAM, ATAF1/2 and CUC2 (NAC) in prickle-free epidermis tissue. The downregulation of these TFs was confirmed by qRT-PCR analysis, indicating a key regulatory role in prickle development. This study adds to the understanding of prickle development mechanisms in red raspberries needed for utilizing genetic engineering strategies for developing prickle-free raspberry cultivars and, possibly, other Rubus species, such as blackberry (Rubus sp.) and black raspberry (R. occidentalis L.).
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8
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Ottaviani G, Keppel G, Götzenberger L, Harrison S, Opedal ØH, Conti L, Liancourt P, Klimešová J, Silveira FAO, Jiménez-Alfaro B, Negoita L, Doležal J, Hájek M, Ibanez T, Méndez-Castro FE, Chytrý M. Linking Plant Functional Ecology to Island Biogeography. TRENDS IN PLANT SCIENCE 2020; 25:329-339. [PMID: 31953170 DOI: 10.1016/j.tplants.2019.12.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 06/10/2023]
Abstract
The study of insular systems has a long history in ecology and biogeography. Island plants often differ remarkably from their noninsular counterparts, constituting excellent models for exploring eco-evolutionary processes. Trait-based approaches can help to answer important questions in island biogeography, yet plant trait patterns on islands remain understudied. We discuss three key hypotheses linking functional ecology to island biogeography: (i) plants in insular systems are characterized by distinct functional trait syndromes (compared with noninsular environments); (ii) these syndromes differ between true islands and terrestrial habitat islands; and (iii) island characteristics influence trait syndromes in a predictable manner. We are convinced that implementing trait-based comparative approaches would considerably further our understanding of plant ecology and evolution in insular systems.
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Affiliation(s)
| | - Gunnar Keppel
- School of Natural and Built Environments, Future Industries Institute, University of South Australia, Adelaide, SA, Australia
| | - Lars Götzenberger
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic
| | - Susan Harrison
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, USA
| | - Øystein H Opedal
- Faculty of Biological and Environmental Sciences, Research Centre for Ecological Change, University of Helsinki, Helsinki, Finland
| | - Luisa Conti
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Pierre Liancourt
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic; Plant Ecology Group, University of Tübingen, Tübingen, Germany
| | - Jitka Klimešová
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic; Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - Fernando A O Silveira
- Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Luka Negoita
- Charles Darwin Research Station, Charles Darwin Foundation, Galápagos Islands, Ecuador
| | - Jiří Doležal
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic; Department of Botany, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic; Laboratory of Tree Ring Research, University of Arizona, Tucson, AZ, USA
| | - Michal Hájek
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Thomas Ibanez
- Department of Biology, University of Hawai'i at Hilo, Hilo, HI, USA
| | | | - Milan Chytrý
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
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9
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Armani M, Goodale UM, Charles‐Dominique T, Barton KE, Yao X, Tomlinson KW. Structural defence is coupled with the leaf economic spectrum across saplings of spiny species. OIKOS 2020. [DOI: 10.1111/oik.06960] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Mohammed Armani
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Menglun, Mengla CN‐666303 Yunnan PR China
- Univ. of Chinese Academy of Science Beijing PR China
| | - Uromi M. Goodale
- Regeneration Ecology, Seed Bio‐physiology and Conservation Laboratory, Plant Ecophysiology and Evolution Group, Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi Univ. Nanning Guangxi PR China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐Bioresources, Guangxi Univ. Nanning Guangxi PR China
| | - Tristan Charles‐Dominique
- Dominique, Inst. of Ecology and Environmental Sciences – Paris, CNRS UMR 7618, Sorbonne Univ. Paris France
| | | | - Xin Yao
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Menglun, Mengla CN‐666303 Yunnan PR China
| | - Kyle W. Tomlinson
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Menglun, Mengla CN‐666303 Yunnan PR China
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10
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Ainsworth A, Drake DR. Classifying Hawaiian plant species along a habitat generalist-specialist continuum: Implications for species conservation under climate change. PLoS One 2020; 15:e0228573. [PMID: 32032387 PMCID: PMC7006925 DOI: 10.1371/journal.pone.0228573] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/17/2020] [Indexed: 11/21/2022] Open
Abstract
Plant communities on tropical high islands, such as the Hawaiian Islands, are predicted to experience rapid climate change, resulting in novel climates. If increased temperature and/or drought exceed plant species' current tolerances, species that are unable to adapt or shift ranges risk extinction. By definition, habitat generalists have a wide niche breadth and thrive in a variety of habitats, whereas habitat specialists have a narrow niche breadth, and typically thrive under more specific climatic characteristics (e.g., cold). The objectives of this study were to: (1) classify plant species in the Hawaiian Islands along a habitat generalist-specialist continuum; (2) independently test the validity of species rankings, using environmental and biogeographic ranges; and (3) identify species' life-history traits that predict species location along the continuum. We quantified specialization for 170 plant species using species co-occurrence data from over one thousand plots to rank species' realized habitat niche breadth using the Jaccard index. The distribution of species along this continuum differed by species biogeographic origin, with endemic plant species ranked on the specialist end and non-native plant species ranked on the generalist end. Habitat specialization rankings also differed for four of nine tested variables (while controlling for biogeographic origin): number of habitat moisture types, minimum elevation, number of Hawaiian Islands, and life form. Life form was the only trait tested that differed across the continuum, with woody species ranked as stronger generalists than herbaceous species; this pattern was particularly evident for non-native species. This indirect method of estimating species' potential climatic flexibility uses increasingly available large plant community data sets with output rankings which represent species' realized habitat niches. Identifying species and plant communities that are on the habitat specialist end of the continuum allows for their prioritization in conservation planning, as globally the loss of specialists is an indication of degradation.
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Affiliation(s)
- Alison Ainsworth
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
- Pacific Island Network Inventory and Monitoring Program, National Park Service, Volcano, Hawaii, United States of America
| | - Donald R. Drake
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
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11
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Armani M, Charles-Dominique T, Barton KE, Tomlinson KW. Developmental constraints and resource environment shape early emergence and investment in spines in saplings. ANNALS OF BOTANY 2020; 124:1133-1142. [PMID: 31560757 PMCID: PMC6943690 DOI: 10.1093/aob/mcz152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 09/23/2019] [Indexed: 06/02/2023]
Abstract
BACKGROUND AND AIMS Herbivory by large mammals imposes a critical recruitment bottleneck on plants in many systems. Spines defend plants against large herbivores, and how early they emerge in saplings may be one of the strongest predictors of sapling survival in herbivore-rich environments. Yet little effort has been directed at understanding the variability in spine emergence across saplings. METHODS We present a multispecies study examining whether and how sapling size, spine type and species' environmental niche (light and precipitation environment) influence early emergence and biomass investment in spines. A phylogenetically diverse pool of 45 species possessing different spine types (spines, prickles and thorns; that are derived from distinct plant organs: leaf, epidermis or cortex, and branch, respectively), were grown under common-garden conditions, and patterns of spine emergence and biomass allocation to spines at 5 and 15 weeks after transplanting were characterized. KEY RESULTS Spine type and species' resource niche were the main factors driving early emergence and investment patterns. Spines emerged earliest in leaf spine-bearing species, and latest in thorn-bearing species. The probability of early spine emergence increased with decreasing precipitation, and was greater in species from open than from closed habitats. Sapling investment in spines changed with plant mass but was contingent on spine type and habitat type. CONCLUSIONS Different spine types have strikingly different timing of expression, suggesting that developmental origins of spines play a critical role in sapling defences. Furthermore, species from different precipitation and light environments (open vs. closed habitats) showed contrasting patterns of early spine expression, suggesting that resource limitation in their native range may have driven divergent evolution of early defence expression.
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Affiliation(s)
- Mohammed Armani
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, China
- University of Chinese Academy of Science, Beijing, China
| | - Tristan Charles-Dominique
- CNRS UMR7618; Sorbonne University, Institute of Ecology and Environmental Sciences Paris, Paris, France
| | - Kasey E Barton
- Department of Botany, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Kyle W Tomlinson
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, China
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12
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Agrawal AA, Hastings AP. Plant Defense by Latex: Ecological Genetics of Inducibility in the Milkweeds and a General Review of Mechanisms, Evolution, and Implications for Agriculture. J Chem Ecol 2019; 45:1004-1018. [PMID: 31755020 DOI: 10.1007/s10886-019-01119-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 12/19/2022]
Abstract
Latex occurs in 10% of plant families, has evolved independently many times, and is the most effective defense of milkweeds against its chewing herbivores. Here we report on new experiments on the heritability and inducibility of latex in several milkweed species. In addition, we review what is known about the genetic and environmental determinants of latex exudation, hormonal regulation, evolution within and among species, and the role and frequency of latex in agricultural crops. We first evaluated genotype-by-environment interactions using ~20 full-sibling genetic families in each of seven Asclepias species treated as controls or attacked by monarch butterfly caterpillars. All species showed substantial genetic variation for latex exudation and six of seven species responded to monarch herbivory (two species increased latex, two species decreased, and two showed variation among genetic families). Exogenous application of jasmonic acid (JA) to three species induced a consistent increase in latex (including species which showed a decline following caterpillar herbivory). We next evaluated three hypotheses for what determines genetic variation for induced latex in A. syriaca: 1) a trade-off with constitutive investment, 2) differential endogenous JA induction, or 3) variation in responsiveness to JA. We only found support for the second hypothesis: genetic families with a stronger JA-burst showed the greatest latex exudation following herbivory. We conclude that most species exhibit a genetic and inducible basis for latex, although genetic variation in inducibility is not pervasive. Finally, we summarized studies across 22 species of Asclepias and found that neither a species' latitude nor its phylogenetic position predicted latex inducibility. Nonetheless, a negative association between constitutive and induced latex across species indicates a macroevolutionary trade-off in allocation to this defense. Our review indicates that jasmonic acid is a key regulator of latex exudation, laticifer morphology, and defensive metabolites within latex. Biotic and abiotic factors strongly modulate latex expression. A survey of latex in food crops revealed that latex and analogous exudates (gums, resins, mucilage) are more common than expected based on their distribution across all plants. In conclusion, despite its widespread occurrence, the literature on latex is currently dominated by rubber trees and milkweeds, and we look forward to the broadening of ecological, agricultural, and mechanistic research into other systems.
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Affiliation(s)
- Anurag A Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA. .,Department of Entomology, Cornell University, Ithaca, NY, USA.
| | - Amy P Hastings
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
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13
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Pandey S, Goel R, Bhardwaj A, Asif MH, Sawant SV, Misra P. Transcriptome analysis provides insight into prickle development and its link to defense and secondary metabolism in Solanum viarum Dunal. Sci Rep 2018; 8:17092. [PMID: 30459319 PMCID: PMC6244164 DOI: 10.1038/s41598-018-35304-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/19/2018] [Indexed: 11/09/2022] Open
Abstract
Prickles are epidermal outgrowth found on the aerial surface of several terrestrial plants. Microscopic studies on prickles of S. viarum Dunal indicated a crucial role of glandular trichomes (GTs) in their development. A spontaneously obtained prickleless mutant showed normal epidermal GTs, but its downstream developmental process to prickle was perturbed. Thus, prickleless mutant offers an ideal opportunity to unveil molecular regulators working downstream to GTs in the prickle formation. Differential transcriptome analysis of epidermis of prickly and prickleless mutant revealed that expression of several defense regulators like ethylene, salicylic acid, PR-proteins, etc. were significantly down-regulated in prickleless mutant, provide an important link between defense and prickle development. It was also noteworthy that the expression of few essential development related TFs like MADS-box, R2R3-MYB, REM, DRL1, were also down-regulated in the stem, petioles, and leaves of prickleless mutant indicating their potential role in prickle development. Interestingly, the gene expression of terpenoid, steroid, flavonoid, glucosinolate, and lignin biosynthesis pathways were up-regulated in prickleless mutant. The biochemical and qRT-PCR analysis also confirmed metabolite elevation. These results indicated that the loss of prickle was compensated by elevated secondary metabolism in the prickleless mutant which played important role in the biotic and abiotic stress management.
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Affiliation(s)
- Shatrujeet Pandey
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ridhi Goel
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India
| | - Archana Bhardwaj
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India
| | - Mehar H Asif
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India
| | - Samir V Sawant
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India.
| | - Pratibha Misra
- Council of Scientific and Industrial Research - National Botanical Research Institute, Lucknow, 226001, India.
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14
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Ochoa-López S, Rebollo R, Barton KE, Fornoni J, Boege K. Risk of herbivore attack and heritability of ontogenetic trajectories in plant defense. Oecologia 2018; 187:413-426. [PMID: 29392442 DOI: 10.1007/s00442-018-4077-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/16/2018] [Indexed: 11/30/2022]
Abstract
Ontogeny has been identified as a main source of variation in the expression of plant phenotypes. However, there is limited information on the mechanisms behind the evolution of ontogenetic trajectories in plant defense. We explored if risk of attack, herbivore damage, heritability, and phenotypic plasticity can promote or constrain the evolutionary potential of ontogenetic trajectories in three defensive traits. We exposed 20 genotypes of Turnera velutina to contrasting environments (shadehouse and field plots), and measured the cyanogenic potential, trichome density, and sugar content in extrafloral nectar in seedlings, juveniles and reproductive plants. We also assessed risk of attack through oviposition preferences, and quantified herbivore damage in the field. We estimated genetic variance, broad sense heritability, and evolvability of the defensive traits at each ontogenetic stage, and of the ontogenetic trajectories themselves. For plants growing in the shadehouse, we found genetic variation and broad sense heritability for cyanogenic potential in seedlings, and for trichome density at all ontogenetic stages. Genetic variation and heritability of ontogenetic trajectories was detected for trichome density only. These genetic pre-requisites for evolution, however, were not detected in the field, suggesting that environmental variation and phenotypic plastic responses mask any heritable variation. Finally, ontogenetic trajectories were found to be plastic, differing between shadehouse and field conditions for the same genetic families. Overall, we provide support for the idea that changes in herbivore pressure can be a mechanism behind the evolution of ontogenetic trajectories. This evolutionary potential, however, can be constrained by phenotypic plasticity expressed in heterogeneous environments.
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Affiliation(s)
- Sofía Ochoa-López
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP. 04510, Mexico City, Mexico
| | - Roberto Rebollo
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP. 04510, Mexico City, Mexico
| | - Kasey E Barton
- Department of Botany, University of Hawai'i at Mānoa, 3190 Maile Way, Room 101, Honolulu, HI, 96822, USA
| | - Juan Fornoni
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP. 04510, Mexico City, Mexico
| | - Karina Boege
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP. 04510, Mexico City, Mexico.
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15
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Damián X, Fornoni J, Domínguez CA, Boege K. Ontogenetic changes in the phenotypic integration and modularity of leaf functional traits. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12971] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xóchitl Damián
- Instituto de EcologíaUniversidad Nacional Autónoma de México Ciudad de México Mexico
| | - Juan Fornoni
- Instituto de EcologíaUniversidad Nacional Autónoma de México Ciudad de México Mexico
| | - César A. Domínguez
- Instituto de EcologíaUniversidad Nacional Autónoma de México Ciudad de México Mexico
| | - Karina Boege
- Instituto de EcologíaUniversidad Nacional Autónoma de México Ciudad de México Mexico
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16
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Barton KE, Boege K. Future directions in the ontogeny of plant defence: understanding the evolutionary causes and consequences. Ecol Lett 2017; 20:403-411. [DOI: 10.1111/ele.12744] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/23/2016] [Accepted: 01/09/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Kasey E. Barton
- Department of Botany University of Hawai'i at Mānoa 3190 Maile Way Room 101 Honolulu Hawai'i 96822 USA
| | - Karina Boege
- Instituto de Ecología Universidad Nacional Autónoma de México. A.P. 20‐275. Ciudad Universitaria C.P. 04510 Ciudad De México México
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17
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Abstract
Plant susceptibility to herbivore attack is determined not just by the suite of defenses present in different tissues of the plant, but also by the capabilities of the herbivore for tolerating, circumventing, or disarming the defenses. This article reviews the elaborate behaviors exhibited by leaf-chewing insects that appear to function specifically to deactivate hostplant defenses. Shortcomings in our understanding and promising areas for future research are highlighted. Behaviors covered include vein cutting, trenching, girdling, leaf clipping, and application of fluids from exocrine glands. Many of these behaviors have a widespread distribution, having evolved independently in multiple insect lineages. Insects utilizing the behaviors include significant agricultural, horticultural, and forestry pests, as well as numerous species important in natural ecosystems. Behavioral, ecological, and phylogenetic studies have documented the importance of the behaviors and their ancient history, but the molecular analysis of how the behaviors affect plant physiology has scarcely begun.
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Affiliation(s)
- David E Dussourd
- Department of Biology, University of Central Arkansas, Conway, Arkansas, 72035;
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18
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Barton KE. Low tolerance to simulated herbivory in Hawaiian seedlings despite induced changes in photosynthesis and biomass allocation. ANNALS OF BOTANY 2016; 117:1053-62. [PMID: 27056973 PMCID: PMC4866310 DOI: 10.1093/aob/mcw021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/16/2015] [Accepted: 12/18/2015] [Indexed: 05/28/2023]
Abstract
BACKGROUND AND AIMS Seedling herbivory is an important factor underlying plant community diversity and structure. While considerable research has characterized seedling defence in terms of resistance, very little is known about seedling tolerance of herbivory. Moreover, few studies have attempted to identify mechanisms of tolerance across a range of plant species. METHODS Seedling tolerance of simulated herbivory was tested in a diverse pool of ten Hawaiian plant species, including several lobeliad species (family Campanulaceae), a grass, a herb and common woody trees and shrubs. Tolerance was measured as the relative survival and growth of damaged plants receiving 50 % defoliation with simultaneous jasmonic acid application compared with undamaged control plants, assessed 1·5 and 5 weeks after damage. Putative mechanisms of tolerance were measured, including photosynthetic parameters, light use efficiency, and biomass allocation reflecting growth priorities, and analysed using species-level regression analyses on tolerance indices. KEY RESULTS No species fully tolerated 50 % defoliation at either harvest date, and simulated herbivory significantly reduced shoot as well as root biomass. Lobeliad species had particularly low tolerance. Species varied considerably in size, biomass allocation parameters and their constitutive (pre-damage) and induced (post-damage) photosynthetic parameters. However, only constitutive levels of non-photochemical quenching were significantly related to tolerance, indicating that species with more efficient light use (and less heat dissipation) are better at tolerating damage than species with high levels of heat dissipation. CONCLUSIONS Native Hawaiian plants expressed low tolerance to a conservative level of simulated herbivory. Root growth decreased in response to damage, but this was not associated with greater tolerance, suggesting this response may be due to allocation constraints following defoliation and not due to adaptive plasticity. Conservation of native island plants threatened by invasive herbivores should prioritize protection for seedlings for improved regeneration and the persistence of native plants in disturbed habitats.
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Affiliation(s)
- Kasey E Barton
- Department of Botany, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
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19
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Ochoa-López S, Villamil N, Zedillo-Avelleyra P, Boege K. Plant defence as a complex and changing phenotype throughout ontogeny. ANNALS OF BOTANY 2015; 116:797-806. [PMID: 26220657 PMCID: PMC4590325 DOI: 10.1093/aob/mcv113] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/21/2015] [Accepted: 06/15/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND AIMS Ontogenetic changes in anti-herbivore defences are common and result from variation in resource availability and herbivore damage throughout plant development. However, little is known about the simultaneous changes of multiple defences across the entire development of plants, and how such changes affect plant damage in the field. The aim of this study was to assess if changes in the major types of plant resistance and tolerance can explain natural herbivore damage throughout plant ontogeny. METHODS An assessment was made of how six defensive traits, including physical, chemical and biotic resistance, simultaneously change across the major transitions of plant development, from seedlings to reproductive stages of Turnera velutina growing in the greenhouse. In addition, an experiment was performed to assess how plant tolerance to artificial damage to leaves changed throughout ontogeny. Finally, leaf damage by herbivores was evaluated in a natural population. KEY RESULTS The observed ontogenetic trajectories of all defences were significantly different, sometimes showing opposite directions of change. Whereas trichome density, leaf toughness, extrafloral nectary abundance and nectar production increased, hydrogen cyanide and compensatory responses decreased throughout plant development, from seedlings to reproductive plants. Only water content was higher at the intermediate juvenile ontogenetic stages. Surveys in a natural population over 3 years showed that herbivores consumed more tissue from juvenile plants than from younger seedlings or older reproductive plants. This is consistent with the fact that juvenile plants were the least defended stage. CONCLUSIONS The results suggest that defensive trajectories are a mixed result of predictions by the Optimal Defence Theory and the Growth-Differentiation Balance Hypothesis. The study emphasizes the importance of incorporating multiple defences and plant ontogeny into further studies for a more comprehensive understanding of plant defence evolution.
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Affiliation(s)
- Sofía Ochoa-López
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP 04510, Mexico DF, Mexico
| | - Nora Villamil
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP 04510, Mexico DF, Mexico
| | - Paulina Zedillo-Avelleyra
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP 04510, Mexico DF, Mexico
| | - Karina Boege
- Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, CP 04510, Mexico DF, Mexico
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20
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Agrawal AA, Patrick ET, Hastings AP. Tests of the coupled expression of latex and cardenolide plant defense in common milkweed (Asclepias syriaca). Ecosphere 2014. [DOI: 10.1890/es14-00161.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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21
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Hoan RP, Ormond RA, Barton KE. Prickly poppies can get pricklier: ontogenetic patterns in the induction of physical defense traits. PLoS One 2014; 9:e96796. [PMID: 24802133 PMCID: PMC4011880 DOI: 10.1371/journal.pone.0096796] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 04/11/2014] [Indexed: 11/18/2022] Open
Abstract
Plant ontogeny is a common source of variation in defense and herbivory. Yet, few studies have investigated how the induction of physical defense traits changes across plant ontogeny. Physical defense traits are costly to produce, and thus, it was predicted that induction as a cost-saving strategy would be particularly favorable for seedlings, leading to ontogenetic declines in the inducibility of these traits. We tested for induction of three different physical defense traits (prickles, latex and leaf toughness) in response to mechanical defoliation and jasmonic acid application using prickly poppies (Argemone glauca and A. mexicana, Papaveraceae) as a model system. Genetic variation in the induction of physical defenses was tested using maternal sib-ships sampled from multiple populations. Both species induced higher densities of laminar prickles, although the magnitude of induction was much higher in the endemic Hawaiian prickly poppy, A. glauca, than in the cosmopolitan A. mexicana. The magnitude of prickle induction was also higher in young compared to older juvenile plant stages in A. glauca, demonstrating a strong role of ontogeny. Neither latex exudation nor leaf toughness was induced in either species. Although significant genetic variation was detected within and among populations for constitutive expression of physical defense traits in Argemone, there was no evidence for genetic variation in the induction of these traits. This study provides the first evidence for the induction of physical defenses in prickly poppies, emphasizing how an ontogenetically explicit framework can reveal new insights into plant defense. Moreover, this study illustrates how sister species comparisons between island vs. continental plants can provide new insights into plant functional and evolutionary ecology, highlighting a fruitful area for future research on more species pairs.
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Affiliation(s)
- Ryan P. Hoan
- Department of Botany, University of Hawai’i at Mānoa, Honolulu, Hawai’i, United States of America
| | - Rhys A. Ormond
- Biology Department, Willamette University, Salem, Oregon, United States of America
| | - Kasey E. Barton
- Department of Botany, University of Hawai’i at Mānoa, Honolulu, Hawai’i, United States of America
- * E-mail:
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