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Ojeda-Prieto L, Medina-van Berkum P, Unsicker SB, Heinen R, Weisser WW. Intraspecific chemical variation of Tanacetum vulgare affects plant growth and reproductive traits in field plant communities. Plant Biol (Stuttg) 2024. [PMID: 38593287 DOI: 10.1111/plb.13646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/31/2024] [Indexed: 04/11/2024]
Abstract
The study investigated the impact of intraspecific plant chemodiversity on plant growth and reproductive traits at both the plant and plot levels. It also aimed to understand how chemodiversity at stand level affects ecosystem functioning and plant-plant interactions. We describe a biodiversity experiment in which we manipulated intraspecific plant chemodiversity at the plot level using six different chemotypes of common tansy (Tanacetum vulgare L., Asteraceae). We tested the effects of chemotype identity and plot-level chemotype richness on plant growth and reproductive traits and plot-level headspace emissions. The study found that plant chemotypes differed in growth and reproductive traits and that traits were affected by the chemotype richness of the plots. Although morphological differences among chemotypes became less pronounced over time, reproductive phenology patterns persisted. Plot-level trait means were also affected by the presence or absence of certain chemotypes in a plot, and the direction of the effect depended on the specific chemotype. However, chemotype richness did not lead to overyielding effects. Lastly, chemotype blends released from plant communities were neither richer nor more diverse with increasing plot-level chemotype richness, but became more dissimilar as they became more dissimilar in their leaf terpenoid profiles. We found that intraspecific plant chemodiversity is crucial in plant-plant interactions. We also found that the effects of chemodiversity on plant growth and reproductive traits were complex and varied depending on the chemotype richness of the plots. This long-term field experiment will allow further investigation into plant-insect interactions and insect community assembly in response to intraspecific chemodiversity.
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Affiliation(s)
- L Ojeda-Prieto
- Terrestrial Ecology Research Group, Department for Life Science Systems, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - P Medina-van Berkum
- Department for Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - S B Unsicker
- Department for Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Plant-Environment-Interactions Group, Botanical Institute, University of Kiel, Kiel, Germany
| | - R Heinen
- Terrestrial Ecology Research Group, Department for Life Science Systems, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - W W Weisser
- Terrestrial Ecology Research Group, Department for Life Science Systems, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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Peng XR, Unsicker SB, Gershenzon J, Qiu MH. Structural diversity, hypothetical biosynthesis, chemical synthesis, and biological activity of Ganoderma meroterpenoids. Nat Prod Rep 2023; 40:1354-1392. [PMID: 37051770 DOI: 10.1039/d3np00006k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Covering: 2018 to 2022Meroterpenoids found in fungal species of the genus Ganoderma and known as Ganoderma meroterpenoids (GMs) are substances composed of a 1,2,4-trisubstituted benzene and a polyunsaturated side chain. These substances have attracted the attention of chemists and pharmacologists due to their diverse structures and significant bioactivity. In this review, we present the structures and possible biosynthesis of representative GMs newly found from 2018 to 2022, as well as chemical synthesis and biological activity of some interesting GMs. We propose for the first time a plausible biosynthetic pathway for GMs, which will certainly motivate further research on the biosynthetic pathway in Ganoderma species, as well as on chemical synthesis of GMs as important bioactive compounds for the purpose of drug development.
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Affiliation(s)
- Xing-Rong Peng
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
| | - Sybille B Unsicker
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Ming-Hua Qiu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
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3
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Eckert S, Eilers EJ, Jakobs R, Anaia RA, Aragam KS, Bloss T, Popp M, Sasidharan R, Schnitzler JP, Stein F, Steppuhn A, Unsicker SB, van Dam NM, Yepes S, Ziaja D, Müller C. Inter-laboratory comparison of plant volatile analyses in the light of intra-specific chemodiversity. Metabolomics 2023; 19:62. [PMID: 37351733 DOI: 10.1007/s11306-023-02026-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/09/2023] [Indexed: 06/24/2023]
Abstract
INTRODUCTION Assessing intraspecific variation in plant volatile organic compounds (VOCs) involves pitfalls that may bias biological interpretation, particularly when several laboratories collaborate on joint projects. Comparative, inter-laboratory ring trials can inform on the reproducibility of such analyses. OBJECTIVES In a ring trial involving five laboratories, we investigated the reproducibility of VOC collections with polydimethylsiloxane (PDMS) and analyses by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). As model plant we used Tanacetum vulgare, which shows a remarkable diversity in terpenoids, forming so-called chemotypes. We performed our ring-trial with two chemotypes to examine the sources of technical variation in plant VOC measurements during pre-analytical, analytical, and post-analytical steps. METHODS Monoclonal root cuttings were generated in one laboratory and distributed to five laboratories, in which plants were grown under laboratory-specific conditions. VOCs were collected on PDMS tubes from all plants before and after a jasmonic acid (JA) treatment. Thereafter, each laboratory (donors) sent a subset of tubes to four of the other laboratories (recipients), which performed TD-GC-MS with their own established procedures. RESULTS Chemotype-specific differences in VOC profiles were detected but with an overall high variation both across donor and recipient laboratories. JA-induced changes in VOC profiles were not reproducible. Laboratory-specific growth conditions led to phenotypic variation that affected the resulting VOC profiles. CONCLUSION Our ring trial shows that despite large efforts to standardise each VOC measurement step, the outcomes differed both qualitatively and quantitatively. Our results reveal sources of variation in plant VOC research and may help to avoid systematic errors in similar experiments.
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Affiliation(s)
- Silvia Eckert
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Elisabeth J Eilers
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Ruth Jakobs
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Redouan Adam Anaia
- Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
- Molecular Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | | | - Tanja Bloss
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Moritz Popp
- Research Unit Environmental Simulation, Helmholtz Zentrum München, Munich, Germany
| | - Rohit Sasidharan
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | | | - Florian Stein
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Anke Steppuhn
- Department of Molecular Botany, Hohenheim University, Stuttgart, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Nicole M van Dam
- Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
- Molecular Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Leibniz Institute of Vegetable and Ornamental Crops, Großbeeren, Germany
| | - Sol Yepes
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Dominik Ziaja
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Caroline Müller
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany.
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4
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Laupheimer S, Kurzweil L, Proels R, Unsicker SB, Stark TD, Dawid C, Hückelhoven R. Volatile-mediated signalling in barley induces metabolic reprogramming and resistance against the biotrophic fungus Blumeria hordei. Plant Biol (Stuttg) 2023; 25:72-84. [PMID: 36377298 DOI: 10.1111/plb.13487] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Plants have evolved diverse secondary metabolites to counteract biotic stress. Volatile organic compounds (VOCs) are released upon herbivore attack or pathogen infection. Recent studies suggest that VOCs can act as signalling molecules in plant defence and induce resistance in distant organs and neighbouring plants. However, knowledge is lacking on the function of VOCs in biotrophic fungal infection on cereal plants. We analysed VOCs emitted by 13 ± 1-day-old barley plants (Hordeum vulgare L.) after mechanical wounding using passive absorbers and TD-GC/MS. We investigated the effect of pure VOC and complex VOC mixtures released from wounded plants on the barley-powdery mildew interaction by pre-exposure in a dynamic headspace connected to a powdery mildew susceptibility assay. Untargeted metabolomics and lipidomics were applied to investigate metabolic changes in sender and receiver barley plants. Green leaf volatiles (GLVs) dominated the volatile profile of wounded barley plants, with (Z)-3-hexenyl acetate (Z3HAC) as the most abundant compound. Barley volatiles emitted after mechanical wounding enhanced resistance in receiver plants towards fungal infection. We found volatile-mediated modifications of the plant-pathogen interaction in a concentration-dependent manner. Pre-exposure with physiologically relevant concentrations of Z3HAC resulted in induced resistance, suggesting that this GLV is a key player in barley anti-pathogen defence. The complex VOC mixture released from wounded barley and Z3HAC induced e.g. accumulation of chlorophyll, linolenic acid and linolenate-conjugated lipids, as well as defence-related secondary metabolites, such as hordatines in receiving plants. Barley VOCs hence induce a complex physiological response and disease resistance in receiver plants.
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Affiliation(s)
- S Laupheimer
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - L Kurzweil
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - R Proels
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - S B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Jena, Germany
| | - T D Stark
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - C Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - R Hückelhoven
- Chair of Phytopathology, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
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5
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Ferlian O, Lintzel EM, Bruelheide H, Guerra CA, Heklau H, Jurburg S, Kühn P, Martinez-Medina A, Unsicker SB, Eisenhauer N, Schädler M. Nutrient status not secondary metabolites drives herbivory and pathogen infestation across differently mycorrhized tree monocultures and mixtures. Basic Appl Ecol 2021; 55:110-123. [PMID: 34493930 PMCID: PMC7611625 DOI: 10.1016/j.baae.2020.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Research on tree diversity and antagonists often neglects plant complementarity. We studied species richness/mycorrhizal type effects on leaf herbivory/pathogens. Mycorrhizal type had different effects on herbivory and pathogen infestation. Elemental not metabolite concentrations determined leaf damage.ld.
Research aimed at understanding the mechanisms underlying the relationship between tree diversity and antagonist infestation is often neglecting resource-use complementarity among plant species. We investigated the effects of tree species identity, species richness, and mycorrhizal type on leaf herbivory and pathogen infestation. We used a tree sapling experiment manipulating the two most common mycorrhizal types, arbuscular mycorrhiza and ectomycorrhiza, via respective tree species in monocultures and two-species mixtures. We visually assessed leaf herbivory and pathogen infestation rates, and measured concentrations of a suite of plant metabolites (amino acids, sugars, and phenolics), leaf elemental concentrations (carbon, nitrogen, and phosphorus), and tree biomass. Tree species and mycorrhizal richness had no significant effect on herbivory and pathogen infestation, whereas species identity and mycorrhizal type had. Damage rates were higher in arbuscular mycorrhizal (AM) than in ectomycorrhizal (EM) trees. Our structural equation model (SEM) indicated that elemental, but not metabolite concentrations, determined herbivory and pathogen infestation, suggesting that the investigated chemical defence strategies may not have been involved in the effects found in our study with tree saplings. Other chemical and physical defence strategies as well as species identity as its determinant may have played a more crucial role in the studied saplings. Furthermore, the SEM indicated a direct positive effect of AM trees on herbivory rates, suggesting that other dominant mechanisms, not considered here, were involved as well. We found differences in the attribution of elemental concentrations between the two rates. This points to the fact that herbivory and pathogen infestation are driven by distinct mechanisms. Our study highlights the importance of biotic contexts for understanding the mechanisms underlying the effects of biodiversity on tree-antagonist interactions.
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Affiliation(s)
- Olga Ferlian
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Esther-Marie Lintzel
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Helge Bruelheide
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Carlos A Guerra
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany
| | - Heike Heklau
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany
| | - Stephanie Jurburg
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Paul Kühn
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany
| | - Ainhoa Martinez-Medina
- Plant-Microorganism Interaction Unit, Institute of Natural Resources and Agrobiology of Salamanca (IRNASA-CSIC), Calle Cordel de Merinas, 40, 37008 Salamanca, Spain
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Martin Schädler
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.,Department of Community Ecology, Helmholtz Centre for Environmental Research - UFZ, Theodor-Lieser-Str. 4, 06120 Halle (Saale), Germany
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6
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Walther C, Baumann P, Luck K, Rothe B, Biedermann PHW, Gershenzon J, Köllner TG, Unsicker SB. Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves. Beilstein J Org Chem 2021; 17:1698-1711. [PMID: 34367348 PMCID: PMC8313976 DOI: 10.3762/bjoc.17.118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 06/29/2021] [Indexed: 11/23/2022] Open
Abstract
Plant volatiles play a major role in plant-insect interactions as defense compounds or attractants for insect herbivores. Recent studies have shown that endophytic fungi are also able to produce volatiles and this raises the question of whether these fungal volatiles influence plant-insect interactions. Here, we qualitatively investigated the volatiles released from 13 endophytic fungal species isolated from leaves of mature black poplar (Populus nigra) trees. The volatile blends of these endophytes grown on agar medium consist of typical fungal compounds, including aliphatic alcohols, ketones and esters, the aromatic alcohol 2-phenylethanol and various sesquiterpenes. Some of the compounds were previously reported as constituents of the poplar volatile blend. For one endophyte, a species of Cladosporium, we isolated and characterized two sesquiterpene synthases that can produce a number of mono- and sesquiterpenes like (E)-β-ocimene and (E)-β-caryophyllene, compounds that are dominant components of the herbivore-induced volatile bouquet of black poplar trees. As several of the fungus-derived volatiles like 2-phenylethanol, 3-methyl-1-butanol and the sesquiterpene (E)-β-caryophyllene, are known to play a role in direct and indirect plant defense, the emission of volatiles from endophytic microbial species should be considered in future studies investigating tree-insect interactions.
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Affiliation(s)
- Christin Walther
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Pamela Baumann
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany.,Chair of Forest Entomology and Protection, Institute of Forest Sciences, University of Freiburg, Fohrenbühl 27, 79252 Stegen-Wittental, Germany
| | - Katrin Luck
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Beate Rothe
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Peter H W Biedermann
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany.,Chair of Forest Entomology and Protection, Institute of Forest Sciences, University of Freiburg, Fohrenbühl 27, 79252 Stegen-Wittental, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
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7
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Eberl F, Fabisch T, Luck K, Köllner TG, Vogel H, Gershenzon J, Unsicker SB. Poplar protease inhibitor expression differs in an herbivore specific manner. BMC Plant Biol 2021; 21:170. [PMID: 33836664 PMCID: PMC8033671 DOI: 10.1186/s12870-021-02936-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Protease inhibitors are defense proteins widely distributed in the plant kingdom. By reducing the activity of digestive enzymes in insect guts, they reduce the availability of nutrients and thus impair the growth and development of the attacking herbivore. One well-characterized class of protease inhibitors are Kunitz-type trypsin inhibitors (KTIs), which have been described in various plant species, including Populus spp. Long-lived woody perennials like poplar trees encounter a huge diversity of herbivores, but the specificity of tree defenses towards different herbivore species is hardly studied. We therefore aimed to investigate the induction of KTIs in black poplar (P. nigra) leaves upon herbivory by three different chewing herbivores, Lymantria dispar and Amata mogadorensis caterpillars, and Phratora vulgatissima beetles. RESULTS We identified and generated full-length cDNA sequences of 17 KTIs that are upregulated upon herbivory in black poplar leaves, and analyzed the expression patterns of the eight most up-regulated KTIs via qRT-PCR. We found that beetles elicited higher transcriptional induction of KTIs than caterpillars, and that both caterpillar species induced similar KTI expression levels. Furthermore, KTI expression strongly correlated with the trypsin-inhibiting activity in the herbivore-damaged leaves, but was not dependent on damage severity, i.e. leaf area loss, for most of the genes. CONCLUSIONS We conclude that the induction of KTIs in black poplar is controlled at the transcriptional level in a threshold-based manner and is strongly influenced by the species identity of the herbivore. However, the underlying molecular mechanisms and ecological consequences of these patterns remain to be investigated.
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Affiliation(s)
- Franziska Eberl
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Thomas Fabisch
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Katrin Luck
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Tobias G. Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Heiko Vogel
- Department of Entomology, MPI-CE, Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology (MPI-CE), Hans-Knöll-Str. 8, 07745 Jena, Germany
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Thakur MP, Künne T, Unsicker SB, Biere A, Ferlian O, Pruschitzki U, Thouvenot L, Türke M, Eisenhauer N. Invasive earthworms reduce chemical defense and increase herbivory and pathogen infection in native trees. J Ecol 2021; 109:763-775. [PMID: 33664527 PMCID: PMC7891629 DOI: 10.1111/1365-2745.13504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 09/01/2020] [Indexed: 05/24/2023]
Abstract
Recent research shows that earthworms can alter defense traits of plants against herbivores and pathogens by affecting soil biochemistry. Yet, the effects of invasive earthworms on defense traits of native plants from previously earthworm-free ecosystems as well as the consequences for multitrophic interactions are virtually unknown.Here we use a combination of an observational study and a complementary experimental study to investigate the effects of invasive earthworms on leaf defense traits, herbivore damage and pathogen infection in two poplar tree species (Populus balsamifera and Populus tremuloides) native to North American boreal forests.Our observational study showed that earthworm invasion was associated with enhanced leaf herbivory (by leaf-chewing insects) in saplings of both tree species. However, we only detected significant shifts in the concentration of chemical defense compounds in response to earthworm invasion for P. balsamifera. Specifically, leaf phenolic concentrations, including salicinoids and catechin, were lower in P. balsamifera from earthworm-invaded sites.Our experimental study confirmed an earthworm-induced reduction in leaf defense levels in P. balsamifera for one of the defense compounds, tremulacin. The experimental study additionally showed that invasive earthworms reduced leaf dry matter content, potentially increasing leaf palatability, and enhanced susceptibility of trees to infection by a fungal pathogen, but not to aphid infestation, in the same tree species. Synthesis. Our results show that invasive earthworms can decrease the concentrations of some chemical defense compounds in P. balsamifera, which could make them susceptible to leaf-chewing insects. Such potential impacts of invasive earthworms are likely to have implications for tree survival and competition, native tree biodiversity and ecosystem functioning.
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Affiliation(s)
- Madhav P. Thakur
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
- Terrestrial Ecology GroupInstitute of Ecology and EvolutionUniversity of BernBernSwitzerland
| | - Tom Künne
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Sybille B. Unsicker
- Department of BiochemistryMax Planck Institute for Chemical EcologyJenaGermany
| | - Arjen Biere
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
| | - Olga Ferlian
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
| | - Ulrich Pruschitzki
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
| | - Lise Thouvenot
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
| | - Manfred Türke
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
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9
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Eisenring M, Unsicker SB, Lindroth RL. Spatial, genetic and biotic factors shape within‐crown leaf trait variation and herbivore performance in a foundation tree species. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael Eisenring
- Department of Entomology University of Wisconsin‐Madison Madison WI USA
- Forest Entomology Swiss Federal Research Institute WSL Birmensdorf Switzerland
| | - Sybille B. Unsicker
- Department of BiochemistryMax Planck Institute for Chemical Ecology Jena Germany
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10
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Lackus ND, Müller A, Kröber TDU, Reichelt M, Schmidt A, Nakamura Y, Paetz C, Luck K, Lindroth RL, Constabel CP, Unsicker SB, Gershenzon J, Köllner TG. The Occurrence of Sulfated Salicinoids in Poplar and Their Formation by Sulfotransferase1. Plant Physiol 2020; 183:137-151. [PMID: 32098786 PMCID: PMC7210634 DOI: 10.1104/pp.19.01447] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/16/2020] [Indexed: 05/23/2023]
Abstract
Salicinoids form a specific class of phenolic glycosides characteristic of the Salicaceae. Although salicinoids accumulate in large amounts and have been shown to be involved in plant defense, their biosynthesis is unclear. We identified two sulfated salicinoids, salicin-7-sulfate and salirepin-7-sulfate, in black cottonwood (Populus trichocarpa). Both compounds accumulated in high amounts in above-ground tissues including leaves, petioles, and stems, but were also found at lower concentrations in roots. A survey of salicin-7-sulfate and salirepin-7-sulfate in a subset of poplar (Populus sp.) and willow (Salix sp.) species revealed a broader distribution within the Salicaceae. To elucidate the formation of these compounds, we studied the sulfotransferase (SOT) gene family in P trichocarpa (PtSOT). One of the identified genes, PtSOT1, was shown to encode an enzyme able to convert salicin and salirepin into salicin-7-sulfate and salirepin-7-sulfate, respectively. The expression of PtSOT1 in different organs of P trichocarpa matched the accumulation of sulfated salicinoids in planta. Moreover, RNA interference-mediated knockdown of SOT1 in gray poplar (Populus × canescens) resulted in decreased levels of sulfated salicinoids in comparison to wild-type plants, indicating that SOT1 is responsible for their formation in planta. The presence of a nonfunctional SOT1 allele in black poplar (Populus nigra) was shown to correlate with the absence of salicin-7-sulfate and salirepin-7-sulfate in this species. Food choice experiments with leaves from wild-type and SOT1 knockdown trees suggest that sulfated salicinoids do not affect the feeding preference of the generalist caterpillar Lymantria dispar A potential role of the sulfated salicinoids in sulfur storage and homeostasis is discussed.
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Affiliation(s)
- Nathalie D Lackus
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Andrea Müller
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Tabea D U Kröber
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Axel Schmidt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Yoko Nakamura
- Nuclear Magnetic Resonance Department, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Christian Paetz
- Nuclear Magnetic Resonance Department, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Katrin Luck
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Richard L Lindroth
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - C Peter Constabel
- Centre for Forest Biology, Department of Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
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11
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Eberl F, Fernandez de Bobadilla M, Reichelt M, Hammerbacher A, Gershenzon J, Unsicker SB. Herbivory meets fungivory: insect herbivores feed on plant pathogenic fungi for their own benefit. Ecol Lett 2020; 23:1073-1084. [PMID: 32307873 DOI: 10.1111/ele.13506] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/19/2020] [Accepted: 03/08/2020] [Indexed: 12/23/2022]
Abstract
Plants are regularly colonised by fungi and bacteria, but plant-inhabiting microbes are rarely considered in studies on plant-herbivore interactions. Here we show that young gypsy moth (Lymantria dispar) caterpillars prefer to feed on black poplar (Populus nigra) foliage infected by the rust fungus Melampsora larici-populina instead of uninfected control foliage, and selectively consume fungal spores. This consumption, also observed in a related lepidopteran species, is stimulated by the sugar alcohol mannitol, found in much higher concentration in fungal tissue and infected leaves than uninfected plant foliage. Gypsy moth larvae developed more rapidly on rust-infected leaves, which cannot be attributed to mannitol but rather to greater levels of total nitrogen, essential amino acids and B vitamins in fungal tissue and fungus-infected leaves. Herbivore consumption of fungi and other microbes may be much more widespread than commonly believed with important consequences for the ecology and evolution of plant-herbivore interactions.
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Affiliation(s)
- Franziska Eberl
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Maite Fernandez de Bobadilla
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Almuth Hammerbacher
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Hatfield, 0028, South Africa
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
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12
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Lackner S, Lackus ND, Paetz C, Köllner TG, Unsicker SB. Aboveground phytochemical responses to belowground herbivory in poplar trees and the consequence for leaf herbivore preference. Plant Cell Environ 2019; 42:3293-3307. [PMID: 31350910 DOI: 10.1111/pce.13628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
Belowground (BG) herbivory can influence aboveground (AG) herbivore performance and food preference via changes in plant chemistry. Most evidence for this phenomenon derives from studies in herbaceous plants but studies in woody plants are scarce. Here we investigated whether and how BG herbivory on black poplar (Populus nigra) trees by Melolontha melolontha larvae influences the feeding preference of Lymantria dispar (gypsy moth) caterpillars. In a food choice assay, caterpillars preferred to feed on leaves from trees that had experienced attack by BG herbivores. Therefore, we investigated the effect of BG herbivory on the phytochemical composition of P. nigra trees alone and in combination with AG feeding by L. dispar caterpillars. BG herbivory did not increase systemic AG tree defences like volatile organic compounds, protease inhibitors and salicinoids. Jasmonates and salicylic acid were also not induced by BG herbivory in leaves but abscisic acid concentrations drastically increased together with proline and few other amino acids. Leaf coating experiments with amino acids suggest that proline might be responsible for the caterpillar feeding preference via presumptive phagostimulatory properties. This study shows that BG herbivory in poplar can modify the feeding preference of AG herbivores via phytochemical changes as a consequence of root-to-shoot signaling.
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Affiliation(s)
- Sandra Lackner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Nathalie D Lackus
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Christian Paetz
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
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13
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Douma JC, Ganzeveld LN, Unsicker SB, Boeckler GA, Dicke M. What makes a volatile organic compound a reliable indicator of insect herbivory? Plant Cell Environ 2019; 42:3308-3325. [PMID: 31330571 PMCID: PMC6972585 DOI: 10.1111/pce.13624] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 05/22/2023]
Abstract
Plants that are subject to insect herbivory emit a blend of so-called herbivore-induced plant volatiles (HIPVs), of which only a few serve as cues for the carnivorous enemies to locate their host. We lack understanding which HIPVs are reliable indicators of insect herbivory. Here, we take a modelling approach to elucidate which physicochemical and physiological properties contribute to the information value of a HIPV. A leaf-level HIPV synthesis and emission model is developed and parameterized to poplar. Next, HIPV concentrations within the canopy are inferred as a function of dispersion, transport and chemical degradation of the compounds. We show that the ability of HIPVs to reveal herbivory varies from almost perfect to no better than chance and interacts with canopy conditions. Model predictions matched well with leaf-emission measurements and field and laboratory assays. The chemical class a compound belongs to predicted the signalling ability of a compound only to a minor extent, whereas compound characteristics such as its reaction rate with atmospheric oxidants, biosynthesis rate upon herbivory and volatility were much more important predictors. This study shows the power of merging fields of plant-insect interactions and atmospheric chemistry research to increase our understanding of the ecological significance of HIPVs.
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Affiliation(s)
- Jacob C. Douma
- Centre for Crop Systems Analysis, Department of Plant SciencesWageningen University6708PBWageningenThe Netherlands
- Laboratory of Entomology, Department of Plant SciencesWageningen University6708PBWageningenThe Netherlands
| | - Laurens N. Ganzeveld
- Meteorology and Air Quality, Department of Environmental SciencesWageningen University6708PBWageningenThe Netherlands
| | - Sybille B. Unsicker
- Department of BiochemistryMax Planck Institute for Chemical Ecology07745JenaGermany
| | - G. Andreas Boeckler
- Department of BiochemistryMax Planck Institute for Chemical Ecology07745JenaGermany
| | - Marcel Dicke
- Laboratory of Entomology, Department of Plant SciencesWageningen University6708PBWageningenThe Netherlands
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14
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McCormick AC, Irmisch S, Boeckler GA, Gershenzon J, Köllner TG, Unsicker SB. Herbivore-induced volatile emission from old-growth black poplar trees under field conditions. Sci Rep 2019; 9:7714. [PMID: 31118456 PMCID: PMC6531464 DOI: 10.1038/s41598-019-43931-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 04/25/2019] [Indexed: 11/17/2022] Open
Abstract
Herbivory is well known to trigger increased emission of volatile organic compounds (VOCs) from plants, but we know little about the responses of mature trees. We measured the volatiles emitted by leaves of old-growth black poplar (Populus nigra) trees after experimental damage by gypsy moth (Lymantria dispar) caterpillars in a floodplain forest, and studied the effect of herbivory on the transcript abundance of two genes involved in the biosynthesis of VOCs, and the accumulation of defence phytohormones. Herbivory significantly increased volatile emission from the experimentally damaged foliage, but not from adjacent undamaged leaves in the damaged branches (i.e., no systemic response). Methylbutyraldoximes, 4,8-dimethyl-1,3,7-nonatriene (DMNT), (Z)-3-hexenol and (E)-β-ocimene, amongst other compounds, were found to be important in distinguishing the blend of herbivore-damaged vs. undamaged leaves. Herbivory also increased expression of PnTPS3 (described here for the first time) and PnCYP79D6-v4 genes at the damaged sites, these genes encode for an (E)-β-ocimene synthase and a P450 enzyme involved in aldoxime formation, respectively, demonstrating de novo biosynthesis of the volatiles produced. Herbivore-damaged leaves had significantly higher levels of jasmonic acid and its conjugate (-)-jasmonic acid-isoleucine. This study shows that mature trees in the field have a robust response to herbivory, producing induced volatiles at the damaged sites even after previous natural herbivory and under changing environmental conditions, however, further studies are needed to establish whether the observed absence of systemic responses is typical of mature poplar trees or if specific conditions are required for their induction.
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Affiliation(s)
- Andrea Clavijo McCormick
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany
- Massey University, College of Sciences, Tennent Drive, 4410, Palmerston North, New Zealand
| | - Sandra Irmisch
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, V6T 1Z4, BC, Canada
| | - G Andreas Boeckler
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Tobias G Köllner
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Straße 8, 07745, Jena, Germany.
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15
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16
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Fabisch T, Gershenzon J, Unsicker SB. Specificity of Herbivore Defense Responses in a Woody Plant, Black Poplar (Populus nigra). J Chem Ecol 2019; 45:162-177. [PMID: 30788656 PMCID: PMC6469625 DOI: 10.1007/s10886-019-01050-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/08/2019] [Accepted: 01/21/2019] [Indexed: 11/25/2022]
Abstract
The specificity of woody plant defense responses to different attacking herbivores is poorly known. We investigated the responses of black poplar (Populus nigra) to leaf feeding by three lepidopteran species (Lymantria dispar, Laothoe populi and Amata mogadorensis) and two leaf beetle species (Phratora vulgatissima and Chrysomela populi). Of the direct defenses monitored, increases in trypsin protease inhibitor activity and the salicinoid salicin were triggered by herbivore damage, but this was not herbivore-specific. Moreover, the majority of leaf salicinoid content was present constitutively and not induced by herbivory. On the other hand, volatile emission profiles did vary among herbivore species, especially between coleopterans and lepidopterans. Monoterpenes and sesquiterpenes were induced in damaged and adjacent undamaged leaves, while the emission of green leaf volatiles, aromatic and nitrogen-containing compounds (known to attract herbivore enemies) was restricted to damaged leaves. In conclusion, indirect defenses appear to show more specific responses to attacking herbivores than direct defenses in this woody plant.
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Affiliation(s)
- Thomas Fabisch
- Max-Planck-Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Max-Planck-Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Max-Planck-Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany.
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17
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Kigathi RN, Weisser WW, Reichelt M, Gershenzon J, Unsicker SB. Plant volatile emission depends on the species composition of the neighboring plant community. BMC Plant Biol 2019; 19:58. [PMID: 30727963 PMCID: PMC6366091 DOI: 10.1186/s12870-018-1541-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 11/20/2018] [Indexed: 05/22/2023]
Abstract
BACKGROUND Plants grow in multi-species communities rather than monocultures. Yet most studies on the emission of volatile organic compounds (VOCs) from plants in response to insect herbivore feeding focus on one plant species. Whether the presence and identity of neighboring plants or plant community attributes, such as plant species richness and plant species composition, affect the herbivore-induced VOC emission of a focal plant is poorly understood. METHODS We established experimental plant communities in pots in the greenhouse where the focal plant species, red clover (Trifolium pratense), was grown in monoculture, in a two species mixture together with Geranium pratense or Dactylis glomerata, or in a mixture of all three species. We measured VOC emission of the focal plant and the entire plant community, with and without herbivory of Spodoptera littoralis caterpillars caged on one red clover individual within the communities. RESULTS Herbivory increased VOC emission from red clover, and increasing plant species richness changed emissions of red clover and also from the entire plant community. Neighbor identity strongly affected red clover emission, with highest emission rates for plants growing together with D. glomerata. CONCLUSION The results from this study indicate that the blend of VOCs perceived by host searching insects can be affected by plant-plant interactions.
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Affiliation(s)
- Rose N. Kigathi
- Institute of Ecology, Friedrich-Schiller-University of Jena, Dornburger Str. 159, 07743 Jena, Germany
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
- Present Address: Department of Biological Sciences, Pwani University, P.O Box 195-80108, Kilifi, Kenya
| | - Wolfgang W. Weisser
- Institute of Ecology, Friedrich-Schiller-University of Jena, Dornburger Str. 159, 07743 Jena, Germany
- Present Address: Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745 Jena, Germany
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18
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Ullah C, Tsai C, Unsicker SB, Xue L, Reichelt M, Gershenzon J, Hammerbacher A. Salicylic acid activates poplar defense against the biotrophic rust fungus Melampsora larici-populina via increased biosynthesis of catechin and proanthocyanidins. New Phytol 2019; 221:960-975. [PMID: 30168132 PMCID: PMC6585937 DOI: 10.1111/nph.15396] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 07/10/2018] [Indexed: 05/14/2023]
Abstract
Poplar trees synthesize flavan-3-ols (catechin and proanthocyanidins) as a defense against foliar rust fungi, but the regulation of this defense response is poorly understood. Here, we investigated the role of hormones in regulating flavan-3-ol accumulation in poplar during rust infection. We profiled levels of defense hormones, signaling genes, and flavan-3-ol metabolites in black poplar leaves at different stages of rust infection. Hormone levels were manipulated by external sprays, genetic engineering, and drought to reveal their role in rust fungal defenses. Levels of salicylic acid (SA), jasmonic acid, and abscisic acid increased in rust-infected leaves and activated downstream signaling, with SA levels correlating closely with those of flavan-3-ols. Pretreatment with the SA analog benzothiadiazole increased flavan-3-ol accumulation by activating the MYB-bHLH-WD40 complex and reduced rust proliferation. Furthermore, transgenic poplar lines overproducing SA exhibited higher amounts of flavan-3-ols constitutively via the same transcriptional activation mechanism. These findings suggest a strong association among SA, flavan-3-ol biosynthesis, and rust resistance in poplars. Abscisic acid also promoted poplar defense against rust infection, but likely through stomatal immunity independent of flavan-3-ols. Jasmonic acid did not confer any apparent defense responses to the fungal pathogen. We conclude that SA activates flavan-3-ol biosynthesis in poplar against rust infection.
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Affiliation(s)
- Chhana Ullah
- Department of BiochemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 807745JenaGermany
| | - Chung‐Jui Tsai
- School of Forestry and Natural ResourcesDepartment of GeneticsDepartment of Plant BiologyUniversity of GeorgiaAthensGA30602USA
| | - Sybille B. Unsicker
- Department of BiochemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 807745JenaGermany
| | - Liangjiao Xue
- Key Laboratory of Forest Genetics and BiotechnologyCo‐Innovation Center for Sustainable Forestry in Southern ChinaCollege of ForestryNanjing Forestry UniversityNanjingJiangsu210037China
| | - Michael Reichelt
- Department of BiochemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 807745JenaGermany
| | - Jonathan Gershenzon
- Department of BiochemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 807745JenaGermany
| | - Almuth Hammerbacher
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPrivate Bag X20Pretoria0028South Africa
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19
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Ullah C, Unsicker SB, Reichelt M, Gershenzon J, Hammerbacher A. Accumulation of Catechin and Proanthocyanidins in Black Poplar Stems After Infection by Plectosphaerella populi: Hormonal Regulation, Biosynthesis and Antifungal Activity. Front Plant Sci 2019; 10:1441. [PMID: 31803202 PMCID: PMC6873352 DOI: 10.3389/fpls.2019.01441] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/16/2019] [Indexed: 05/08/2023]
Abstract
Flavan-3-ols including the monomeric catechin and the polymeric proanthocyanidins (PAs) are abundant phenolic metabolites in poplar (Populus spp.) previously described to protect leaves against pathogen infection. However, it is not known whether stems are also defended in this way. Here we investigated flavan-3-ol accumulation, activity, and the regulation of formation in black poplar (P. nigra) stems after infection by a newly described fungal stem pathogen, Plectosphaerella populi, which forms canker-like lesions in stems. We showed that flavan-3-ol contents increased in P. populi-infected black poplar stems over the course of infection compared to non-infected controls. Transcripts of leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) genes involved in the last steps of flavan-3-ol biosynthesis were also upregulated upon fungal infection indicating de novo biosynthesis. Amending culture medium with catechin and PAs reduced the mycelial growth of P. populi, suggesting that these metabolites act as anti-pathogen defenses in poplar in vivo. Among the hormones, salicylic acid (SA) was higher in P. populi-infected tissues compared to the non-infected controls over the course of infection studied, while jasmonic acid (JA) and JA-isoleucine (JA-Ile) levels were higher than controls only at the early stages of infection. Interestingly, cytokinins (CKs) were also upregulated in P. populi-infected stems. Poplar saplings treated with CK showed decreased levels of flavan-3-ols and SA in stems suggesting a negative association between CK and flavan-3-ol accumulation. Taken together, the sustained upregulation of SA in correlation with catechin and PA accumulation suggests that this is the dominant hormone inducing the formation of antifungal flavan-3-ols during P. populi infection of poplar stems.
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Affiliation(s)
- Chhana Ullah
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- *Correspondence: Chhana Ullah,
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Almuth Hammerbacher
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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20
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Lackus ND, Lackner S, Gershenzon J, Unsicker SB, Köllner TG. The occurrence and formation of monoterpenes in herbivore-damaged poplar roots. Sci Rep 2018; 8:17936. [PMID: 30560919 PMCID: PMC6299004 DOI: 10.1038/s41598-018-36302-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/14/2018] [Indexed: 11/18/2022] Open
Abstract
Volatiles are often released upon herbivory as plant defense compounds. While the formation of volatiles above-ground has been intensively studied, little is known about herbivore-induced root volatiles. Here, we show that cockchafer larvae-damaged roots of Populus trichocarpa and P. nigra release a mixture of monoterpenes, including (−)-α-pinene, (−)-camphene, (−)-β-pinene, p-cymene, and 1,8-cineole. Three terpene synthases, PtTPS16 and PtTPS21 from P. trichocarpa and PnTPS4 from P. nigra, could be identified and characterized in vitro. PnTPS4 was found to produce 1,8-cineole as sole product. PtTPS16 and PtTPS21, although highly similar to each other, showed different product specificities and produced γ-terpinene and a mixture of (−)-camphene, (−)-α-pinene, (−)-β-pinene, and (−)-limonene, respectively. Four active site residues were found to determine the different product specificities of the two enzymes. The expression profiles of PtTPS16, PtTPS21, and PnTPS4 in undamaged and herbivore-damaged poplar roots generally matched the emission pattern of monoterpenes, indicating that monoterpene emission in roots is mainly determined at the gene transcript level. Bioassays with Phytophtora cactorum (Oomycetes) revealed inhibitory effects of vapor-phase 1,8-cineole and (−)-β-pinene on the growth of this important plant pathogen. Thus herbivore-induced volatile monoterpenes may have a role in defense against pathogens that cause secondary infections after root wounding.
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Affiliation(s)
- Nathalie D Lackus
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Sandra Lackner
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Tobias G Köllner
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll-Strasse 8, 07745, Jena, Germany.
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21
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Junker RR, Kuppler J, Amo L, Blande JD, Borges RM, van Dam NM, Dicke M, Dötterl S, Ehlers BK, Etl F, Gershenzon J, Glinwood R, Gols R, Groot AT, Heil M, Hoffmeister M, Holopainen JK, Jarau S, John L, Kessler A, Knudsen JT, Kost C, Larue-Kontic AAC, Leonhardt SD, Lucas-Barbosa D, Majetic CJ, Menzel F, Parachnowitsch AL, Pasquet RS, Poelman EH, Raguso RA, Ruther J, Schiestl FP, Schmitt T, Tholl D, Unsicker SB, Verhulst N, Visser ME, Weldegergis BT, Köllner TG. Covariation and phenotypic integration in chemical communication displays: biosynthetic constraints and eco-evolutionary implications. New Phytol 2018; 220:739-749. [PMID: 28256726 DOI: 10.1111/nph.14505] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/29/2017] [Indexed: 05/04/2023]
Abstract
Chemical communication is ubiquitous. The identification of conserved structural elements in visual and acoustic communication is well established, but comparable information on chemical communication displays (CCDs) is lacking. We assessed the phenotypic integration of CCDs in a meta-analysis to characterize patterns of covariation in CCDs and identified functional or biosynthetically constrained modules. Poorly integrated plant CCDs (i.e. low covariation between scent compounds) support the notion that plants often utilize one or few key compounds to repel antagonists or to attract pollinators and enemies of herbivores. Animal CCDs (mostly insect pheromones) were usually more integrated than those of plants (i.e. stronger covariation), suggesting that animals communicate via fixed proportions among compounds. Both plant and animal CCDs were composed of modules, which are groups of strongly covarying compounds. Biosynthetic similarity of compounds revealed biosynthetic constraints in the covariation patterns of plant CCDs. We provide a novel perspective on chemical communication and a basis for future investigations on structural properties of CCDs. This will facilitate identifying modules and biosynthetic constraints that may affect the outcome of selection and thus provide a predictive framework for evolutionary trajectories of CCDs in plants and animals.
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Affiliation(s)
- Robert R Junker
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
| | - Jonas Kuppler
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
| | - Luisa Amo
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), NL-6700, EH Wageningen, the Netherlands
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales (CSIC), 28006, Madrid, Spain
| | - James D Blande
- Department of Environmental and Biological Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Renee M Borges
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India
| | - Nicole M van Dam
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig/Friedrich-Schiller-Universität Jena, Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Marcel Dicke
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Stefan Dötterl
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
| | - Bodil K Ehlers
- Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark
| | - Florian Etl
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
- Department of Botany and Biodiversity Research, University of Vienna, 1030, Vienna, Austria
| | - Jonathan Gershenzon
- Department of Biochemistry, Max-Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Robert Glinwood
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Box 7043, S750 07, Uppsala, Sweden
| | - Rieta Gols
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Astrid T Groot
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
- Department of Entomology, Max Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Martin Heil
- Departamento de Ingeniería Genética, CINVESTAV - Irapuato, Irapuato, CP 36821, México
| | - Mathias Hoffmeister
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
| | - Jarmo K Holopainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, 70211, Kuopio, Finland
| | - Stefan Jarau
- Institute for Neurobiology, Ulm University, Helmholtzstr. 10/1, 89081, Ulm, Germany
| | - Lena John
- Institute for Neurobiology, Ulm University, Helmholtzstr. 10/1, 89081, Ulm, Germany
| | - Andre Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Jette T Knudsen
- Deptartment of Biology, Lund University, SE 223 62, Lund, Sweden
- Nattaro Labs AB, Medicon Village, 223 81, Lund, Sweden
| | - Christian Kost
- Max Planck Institute for Chemical Ecology, Research Group Experimental Ecology and Evolution, 07745, Jena, Germany
- Department of Ecology, School of Biology/Chemistry, University of Osnabrück, 49074, Osnabrück, Germany
| | - Anne-Amélie C Larue-Kontic
- Department of Ecology and Evolution, University of Salzburg, Hellbrunnerstrasse 34, 5020, Salzburg, Austria
| | - Sara Diana Leonhardt
- Department of Animal Ecology and Tropical Biology, Würzburg University, 97074, Würzburg, Germany
| | - Dani Lucas-Barbosa
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Cassie J Majetic
- Department of Biology, Saint Mary's College, Notre Dame, IN, 46556, USA
| | - Florian Menzel
- Institute of Zoology, University of Mainz, 55128, Mainz, Germany
| | - Amy L Parachnowitsch
- Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, 75236, Sweden
| | - Rémy S Pasquet
- Department of ECOBIO, IRD, 44 Bd de Dunkerque, 13572, Marseille Cedex 02, France
| | - Erik H Poelman
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Joachim Ruther
- Institute of Zoology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland
| | - Thomas Schmitt
- Department of Animal Ecology and Tropical Biology, Würzburg University, 97074, Würzburg, Germany
| | - Dorothea Tholl
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Sybille B Unsicker
- Department of Biochemistry, Max-Planck Institute for Chemical Ecology, 07745, Jena, Germany
| | - Niels Verhulst
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), NL-6700, EH Wageningen, the Netherlands
| | - Berhane T Weldegergis
- Laboratory of Entomology, Wageningen University, PO Box 16, 6700 AA, Wageningen, the Netherlands
| | - Tobias G Köllner
- Department of Biochemistry, Max-Planck Institute for Chemical Ecology, 07745, Jena, Germany
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Eberl F, Hammerbacher A, Gershenzon J, Unsicker SB. Leaf rust infection reduces herbivore-induced volatile emission in black poplar and attracts a generalist herbivore. New Phytol 2018; 220:760-772. [PMID: 28418581 DOI: 10.1111/nph.14565] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 03/02/2017] [Indexed: 05/09/2023]
Abstract
Plants release complex volatile blends after separate attack by herbivores and pathogens, which play many roles in interactions with other organisms. Large perennials are often attacked by multiple enemies, but the effect of combined attacks on volatile emission is rarely studied, particularly in trees. We infested Populus nigra trees with a pathogen, the rust fungus Melampsora larici-populina, and Lymantria dispar caterpillars alone and in combination. We investigated poplar volatile emission and its regulation, as well as the behavior of the caterpillars towards volatiles from rust-infected and uninfected trees. Both the rust fungus and the caterpillars alone induced volatile emission from poplar trees. However, the herbivore-induced volatile emission was significantly reduced when trees were under combined attack by the herbivore and the fungus. Herbivory induced terpene synthase transcripts as well as jasmonate concentrations, but these increases were suppressed when the tree was additionally infected with rust. Caterpillars preferred volatiles from rust-infected over uninfected trees. Our results suggest a defense hormone crosstalk upon combined herbivore-pathogen attack in poplar trees which results in lowered emission of herbivore-induced volatiles. This influences the preference of herbivores, and might have other far-reaching consequences for the insect and pathogen communities in natural poplar forests.
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Affiliation(s)
- Franziska Eberl
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Almuth Hammerbacher
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany
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23
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Abstract
The interaction of plants and their herbivorous opponents has shaped the evolution of an intricate network of defences and counter-defences for millions of years. The result is an astounding diversity of phytochemicals and plant strategies to fight and survive. Trees are specifically challenged to resist the plethora of abiotic and biotic stresses due to their dimension and longevity. Here, we review the recent literature on the consequences of phytochemical variation in trees on insect-tree-herbivore interactions. We discuss the importance of genotypic and phenotypic variation in tree defence against insects and suggest some molecular mechanisms that might bring about phytochemical diversity in crowns of individual trees.
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Affiliation(s)
- Jörn S Lämke
- Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany.
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24
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Eberl F, Perreca E, Vogel H, Wright LP, Hammerbacher A, Veit D, Gershenzon J, Unsicker SB. Rust Infection of Black Poplar Trees Reduces Photosynthesis but Does Not Affect Isoprene Biosynthesis or Emission. Front Plant Sci 2018; 9:1733. [PMID: 30538714 PMCID: PMC6277707 DOI: 10.3389/fpls.2018.01733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/07/2018] [Indexed: 05/13/2023]
Abstract
Poplar (Populus spp.) trees are widely distributed and play an important role in ecological communities and in forestry. Moreover, by releasing high amounts of isoprene, these trees impact global atmospheric chemistry. One of the most devastating diseases for poplar is leaf rust, caused by fungi of the genus Melampsora. Despite the wide distribution of these biotrophic pathogens, very little is known about their effects on isoprene biosynthesis and emission. We therefore infected black poplar (P. nigra) trees with the rust fungus M. larici-populina and monitored isoprene emission and other physiological parameters over the course of infection to determine the underlying mechanisms. We found an immediate and persistent decrease in photosynthesis during infection, presumably caused by decreased stomatal conductance mediated by increased ABA levels. At the same time, isoprene emission remained stable during the time course of infection, consistent with the stability of its biosynthesis. There was no detectable change in the levels of intermediates or gene transcripts of the methylerythritol 4-phosphate (MEP) pathway in infected compared to control leaves. Rust infection thus does not affect isoprene emission, but may still influence the atmosphere via decreased fixation of CO2.
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Affiliation(s)
- Franziska Eberl
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Erica Perreca
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Louwrance P. Wright
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Zeiselhof Research Farm, Pretoria, South Africa
| | - Almuth Hammerbacher
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Daniel Veit
- Technical Service, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- *Correspondence: Sybille B. Unsicker,
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25
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Ullah C, Unsicker SB, Fellenberg C, Constabel CP, Schmidt A, Gershenzon J, Hammerbacher A. Flavan-3-ols Are an Effective Chemical Defense against Rust Infection. Plant Physiol 2017; 175:1560-1578. [PMID: 29070515 PMCID: PMC5717727 DOI: 10.1104/pp.17.00842] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/23/2017] [Indexed: 05/02/2023]
Abstract
Phenolic secondary metabolites are often thought to protect plants against attack by microbes, but their role in defense against pathogen infection in woody plants has not been investigated comprehensively. We studied the biosynthesis, occurrence, and antifungal activity of flavan-3-ols in black poplar (Populus nigra), which include both monomers, such as catechin, and oligomers, known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases and two anthocyanidin reductases from P. nigra involved in catalyzing the last steps of flavan-3-ol biosynthesis, leading to the formation of catechin [2,3-trans-(+)-flavan-3-ol] and epicatechin [2,3-cis-(-)-flavan-3-ol], respectively. Poplar trees that were inoculated with the biotrophic rust fungus (Melampsora larici-populina) accumulated higher amounts of catechin and PAs than uninfected trees. The de novo-synthesized catechin and PAs in the rust-infected poplar leaves accumulated significantly at the site of fungal infection in the lower epidermis. In planta concentrations of these compounds strongly inhibited rust spore germination and reduced hyphal growth. Poplar genotypes with constitutively higher levels of catechin and PAs as well as hybrid aspen (Populus tremula × Populus alba) overexpressing the MYB134 transcription factor were more resistant to rust infection. Silencing PnMYB134, on the other hand, decreased flavan-3-ol biosynthesis and increased susceptibility to rust infection. Taken together, our data indicate that catechin and PAs are effective antifungal defenses in poplar against foliar rust infection.
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Affiliation(s)
- Chhana Ullah
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Christin Fellenberg
- Department of Biology and Centre for Forest Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada
| | - C Peter Constabel
- Department of Biology and Centre for Forest Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada
| | - Axel Schmidt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Almuth Hammerbacher
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0028, South Africa
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26
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Boeckler GA, Paetz C, Feibicke P, Gershenzon J, Unsicker SB. Metabolism of poplar salicinoids by the generalist herbivore Lymantria dispar (Lepidoptera). Insect Biochem Mol Biol 2016; 78:39-49. [PMID: 27503687 DOI: 10.1016/j.ibmb.2016.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/03/2016] [Accepted: 08/03/2016] [Indexed: 05/17/2023]
Abstract
The survival of insect herbivores on chemically defended plants may often depend on their ability to metabolize these defense compounds. However, only little knowledge is available on how insects actually process most plant defense compounds. We investigated the metabolism of salicinoids, a major group of phenolic glycosides in poplar and willow species, by a generalist herbivore, the gypsy moth (Lymantria dispar). Seven salicinoid metabolites identified in gypsy moth caterpillar feces were mostly conjugates with glucose, cysteine or glycine. Two of the glucosides were phosphorylated, a feature not previously reported for insect metabolites of plant defense compounds. The origins of these metabolites were traced to specific moieties of three major poplar salicinoids ingested, salicin, salicortin and tremulacin. Based on the observed metabolite patterns we were able to deduce the initial steps of salicinoid breakdown in L. dispar guts, which involves cleavage of ester bonds. The conjugated molecules were effectively eliminated within 24 h after ingestion. Some of the initial breakdown products (salicin and catechol) demonstrated negative effects on insect growth and survival in bioassays on artificial diets. Gypsy moth caterpillars with prior feeding experience on salicinoid-containing poplar foliage converted salicinoids to the identified metabolites more efficiently than caterpillars pre-fed an artificial diet. The majority of the metabolites we identified were also produced by other common poplar-feeding insects. The conversion of plant defenses like salicinoids to a variety of water-soluble sugar, phosphate and amino acid conjugates and their subsequent excretion fits the general detoxification strategy found in insect herbivores and other animals.
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Affiliation(s)
- G Andreas Boeckler
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany.
| | - Christian Paetz
- Biosynthesis/NMR Research Group, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany
| | - Peter Feibicke
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, 07745, Jena, Germany.
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27
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Abstract
Herbivores are important drivers of plant species coexistence and community assembly. However, detailed mechanistic information on how herbivores affect dominance hierarchies between plant species is scarce. Here, we used data of a multi-site herbivore exclusion experiment in grasslands to assess changes in the cover of 28 plant species in response to aboveground pesticide. application. Moreover, we assessed species-specific values of plant defense of these 28 species measured as the performance of a generalist caterpillar, and the preference of the caterpillar and a slug species in no-choice and choice feeding experiments, respectively. We show that more preferred species in the feeding experiments were those that increased in cover after herbivore exclusion in the field, whereas less preferred ones decreased. Herbivore performance and several measured leaf traits were not related to the change in plant cover in the field in response to herbivore removal. Additionally, the generalist slug and the generalist caterpillar preferred and disliked the same plant species, indicating that they perceive the balance between defense and nutritional value similarly. We conclude that the growth-defense trade-off in grassland species acts via the preference of herbivores and that among-species variation in plant growth and preference to herbivores drives plant community composition.
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28
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McCormick AC, Reinecke A, Gershenzon J, Unsicker SB. Feeding Experience Affects the Behavioral Response of Polyphagous Gypsy Moth Caterpillars to Herbivore-induced Poplar Volatiles. J Chem Ecol 2016; 42:382-93. [PMID: 27170157 PMCID: PMC4912982 DOI: 10.1007/s10886-016-0698-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/22/2016] [Accepted: 04/28/2016] [Indexed: 11/27/2022]
Abstract
Plant volatiles influence host selection of herbivorous insects. Since volatiles often vary in space and time, herbivores (especially polyphagous ones) may be able to use these compounds as cues to track variation in host plant quality based on their innate abilities and previous experience. We investigated the behavioral response of naïve (fed on artificial diet) and experienced (fed on poplar) gypsy moth (Lymantria dispar) caterpillars, a polyphagous species, towards constitutive and herbivore-induced black poplar (Populus nigra) volatiles at different stages of herbivore attack. In Y-tube olfactometer assays, both naïve and experienced caterpillars were attracted to constitutive volatiles and volatiles released after short-term herbivory (up to 6 hr). Naïve caterpillars also were attracted to volatiles released after longer-term herbivory (24-30 hr), but experienced caterpillars preferred the odor of undamaged foliage. A multivariate statistical analysis comparing the volatile emission of undamaged plants vs. plants after short and longer-term herbivory, suggested various compounds as being responsible for distinguishing between the odors of these plants. Ten compounds were selected for individual testing of caterpillar behavioral responses in a four-arm olfactometer. Naïve caterpillars spent more time in arms containing (Z)-3-hexenol and (Z)-3-hexenyl acetate than in solvent permeated arms, while avoiding benzyl cyanide and salicyl aldehyde. Experienced caterpillars avoided benzyl cyanide and preferred (Z)-3-hexenyl acetate and the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) over solvent. Only responses to DMNT were significantly different when comparing experienced and naïve caterpillars. The results show that gypsy moth caterpillars display an innate behavioral response towards constitutive and herbivore-induced plant volatiles, but also that larval behavior is plastic and can be modulated by previous feeding experience.
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Affiliation(s)
- Andrea C McCormick
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
- Institute of Agriculture and Environment, Massey University, Private Bag 11222, 4442, Palmerston North, New Zealand.
| | - Andreas Reinecke
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
- Department of Behavioral Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 7, 82319, Seewiesen, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
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29
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Miehe-Steier A, Roscher C, Reichelt M, Gershenzon J, Unsicker SB. Light and Nutrient Dependent Responses in Secondary Metabolites of Plantago lanceolata Offspring Are Due to Phenotypic Plasticity in Experimental Grasslands. PLoS One 2015; 10:e0136073. [PMID: 26336100 PMCID: PMC4559451 DOI: 10.1371/journal.pone.0136073] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 07/30/2015] [Indexed: 12/27/2022] Open
Abstract
A few studies in the past have shown that plant diversity in terms of species richness and functional composition can modify plant defense chemistry. However, it is not yet clear to what extent genetic differentiation of plant chemotypes or phenotypic plasticity in response to diversity-induced variation in growth conditions or a combination of both is responsible for this pattern. We collected seed families of ribwort plantain (Plantago lanceolata) from six-year old experimental grasslands of varying plant diversity (Jena Experiment). The offspring of these seed families was grown under standardized conditions with two levels of light and nutrients. The iridoid glycosides, catalpol and aucubin, and verbascoside, a caffeoyl phenylethanoid glycoside, were measured in roots and shoots. Although offspring of different seed families differed in the tissue concentrations of defensive metabolites, plant diversity in the mothers' environment did not explain the variation in the measured defensive metabolites of P. lanceolata offspring. However secondary metabolite levels in roots and shoots were strongly affected by light and nutrient availability. Highest concentrations of iridoid glycosides and verbascoside were found under high light conditions, and nutrient availability had positive effects on iridoid glycoside concentrations in plants grown under high light conditions. However, verbascoside concentrations decreased under high levels of nutrients irrespective of light. The data from our greenhouse study show that phenotypic plasticity in response to environmental variation rather than genetic differentiation in response to plant community diversity is responsible for variation in secondary metabolite concentrations of P. lanceolata in the six-year old communities of the grassland biodiversity experiment. Due to its large phenotypic plasticity P. lanceolata has the potential for a fast and efficient adjustment to varying environmental conditions in plant communities of different species richness and functional composition.
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Affiliation(s)
- Annegret Miehe-Steier
- Max Planck Institute for Chemical Ecology, Jena, Germany
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Christiane Roscher
- Max Planck Institute for Biogeochemistry, Jena, Germany
- UFZ, Helmholtz Centre for Environmental Research, Department of Community Ecology, Halle, Germany
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30
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Unsicker SB, Gershenzon J, Köllner TG. Beetle feeding induces a different volatile emission pattern from black poplar foliage than caterpillar herbivory. Plant Signal Behav 2015; 10:e987522. [PMID: 25831045 PMCID: PMC4623510 DOI: 10.4161/15592324.2014.987522] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Herbivore-induced plant volatile emission is often considered to be attacker species-specific, but most experimental evidence comes from short lived herbaceous species. In a recent study we showed that black poplar (Populus nigra) trees emit a complex blend of volatiles from damaged leaves when they are attacked by generalist gypsy moth (Lymantria dispar) caterpillars. Minor nitrogenous volatiles were especially characteristic of this blend. Here we show that attack on P. nigra by a beetle species, Phratora vulgatissima (Coleoptera, Chrysomelidae), led to the emission of the same compounds as already observed after caterpillar herbivory, but with striking quantitative changes in the blend. The consequences for attraction of herbivore enemies are discussed.
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Affiliation(s)
| | - Jonathan Gershenzon
- Department of Biochemistry; Max Planck Institute for Chemical Ecology; Jena, Germany
| | - Tobias G. Köllner
- Department of Biochemistry; Max Planck Institute for Chemical Ecology; Jena, Germany
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Irmisch S, Clavijo McCormick A, Günther J, Schmidt A, Boeckler GA, Gershenzon J, Unsicker SB, Köllner TG. Herbivore-induced poplar cytochrome P450 enzymes of the CYP71 family convert aldoximes to nitriles which repel a generalist caterpillar. Plant J 2014; 80:1095-107. [PMID: 25335755 DOI: 10.1111/tpj.12711] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 05/05/2023]
Abstract
Numerous plant species emit volatile nitriles upon herbivory, but the biosynthesis as well as the relevance of these nitrogenous compounds in plant-insect interactions remains unknown. Populus trichocarpa has been shown to produce a complex blend of nitrogenous volatiles, including aldoximes and nitriles, after herbivore attack. The aldoximes were previously reported to be derived from amino acids by the action of cytochrome P450 enzymes of the CYP79 family. Here we show that nitriles are derived from aldoximes by another type of P450 enzyme in P. trichocarpa. First, feeding of deuterium-labeled phenylacetaldoxime to poplar leaves resulted in incorporation of the label into benzyl cyanide, demonstrating that poplar volatile nitriles are derived from aldoximes. Then two P450 enzymes, CYP71B40v3 and CYP71B41v2, were characterized that produce aliphatic and aromatic nitriles from their respective aldoxime precursors. Both possess typical P450 sequence motifs but do not require added NADPH or cytochrome P450 reductase for catalysis. Since both enzymes are expressed after feeding by gypsy moth caterpillars, they are likely to be involved in herbivore-induced volatile nitrile emission in P. trichocarpa. Olfactometer experiments showed that these volatile nitriles have a strong repellent activity against gypsy moth caterpillars, suggesting they play a role in induced direct defense against poplar herbivores.
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Affiliation(s)
- Sandra Irmisch
- Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
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Clavijo McCormick A, Boeckler GA, Köllner TG, Gershenzon J, Unsicker SB. The timing of herbivore-induced volatile emission in black poplar (Populus nigra) and the influence of herbivore age and identity affect the value of individual volatiles as cues for herbivore enemies. BMC Plant Biol 2014; 14:304. [PMID: 25429804 PMCID: PMC4262996 DOI: 10.1186/s12870-014-0304-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/23/2014] [Indexed: 05/08/2023]
Abstract
BACKGROUND The role of herbivore-induced plant volatiles as signals mediating the attraction of herbivore enemies is a well-known phenomenon. Studies with short-lived herbaceous plant species have shown that various biotic and abiotic factors can strongly affect the quantity, composition and timing of volatile emission dynamics. However, there is little knowledge on how these factors influence the volatile emission of long-lived woody perennials. The aim of this study was to investigate the temporal dynamics of herbivore-induced volatile emission of black poplar (Populus nigra) through several day-night cycles following the onset of herbivory. We also determined the influence of different herbivore species, caterpillars of the gypsy moth (Lymantria dispar) and poplar hawkmoth (Laothoe populi), and different herbivore developmental stages on emission. RESULTS The emission dynamics of major groups of volatile compounds differed strikingly in response to the timing of herbivory and the day-night cycle. The emission of aldoximes, salicyl aldehyde, and to a lesser extent, green leaf volatiles began shortly after herbivore attack and ceased quickly after herbivore removal, irrespective of the day-night cycle. However, the emission of most terpenes showed a more delayed reaction to the start and end of herbivory, and emission was significantly greater during the day compared to the night. The identity of the caterpillar species caused only slight changes in emission, but variation in developmental stage had a strong impact on volatile emission with early instar L. dispar inducing more nitrogenous volatiles and terpenoids than late instar caterpillars of the same species. CONCLUSIONS The results indicate that only a few of the many herbivore-induced black poplar volatiles are released in tight correlation with the timing of herbivory. These may represent the most reliable cues for herbivore enemies and, interestingly, have been shown in a recent study to be the best attractants for an herbivore enemy that parasitizes gypsy moth larvae feeding on black poplar.
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Affiliation(s)
- Andrea Clavijo McCormick
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany
| | - G Andreas Boeckler
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany
| | - Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany
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Clavijo McCormick A, Gershenzon J, Unsicker SB. Little peaks with big effects: establishing the role of minor plant volatiles in plant-insect interactions. Plant Cell Environ 2014; 37:1836-44. [PMID: 24749758 DOI: 10.1111/pce.12357] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 04/09/2014] [Accepted: 04/09/2014] [Indexed: 05/04/2023]
Abstract
Plants emit complex mixtures of volatile organic compounds from floral and vegetative tissue, especially after herbivore damage, so it is difficult to associate individual compounds with activity towards pollinators, herbivores or herbivore enemies. Attention has usually focused upon the biological activity of the most abundant compounds; but here, we detail a number of reports implicating minor volatiles in attractant or deterrent roles. This is not surprising given the exquisite sensitivity of insect olfactory systems for certain substances. In this context, it is worth reconsidering the methods involved in sampling volatile compounds from plants, measuring their abundance and determining their biological activity to ensure that minor compounds are not overlooked. Here, we describe various experimental approaches and chemical and statistical methods that should increase the chance of detecting minor compounds with major biological activities.
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Clavijo McCormick A, Irmisch S, Reinecke A, Boeckler GA, Veit D, Reichelt M, Hansson BS, Gershenzon J, Köllner TG, Unsicker SB. Herbivore-induced volatile emission in black poplar: regulation and role in attracting herbivore enemies. Plant Cell Environ 2014; 37:1909-23. [PMID: 24471487 DOI: 10.1111/pce.12287] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 05/05/2023]
Abstract
After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts.
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Boeckler GA, Towns M, Unsicker SB, Mellway RD, Yip L, Hilke I, Gershenzon J, Constabel CP. Transgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera. J Chem Ecol 2014; 40:150-8. [PMID: 24496605 DOI: 10.1007/s10886-014-0383-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 01/10/2014] [Accepted: 01/16/2014] [Indexed: 11/29/2022]
Abstract
Transgenic hybrid aspen (Populus tremula x tremuloides) overexpressing the MYB134 tannin regulatory gene show dramatically enhanced condensed tannin (proanthocyanidin) levels, as well as shifts in other phenolic metabolites. A series of insect bioassays with forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar) caterpillars was carried out to determine how this metabolic shift affects food preference and performance of generalist tree-feeding lepidopterans. Both species showed a distinct preference for the high-tannin MYB134 overexpressor plants, and L. dispar performance was enhanced relative to controls. L. dispar reached greater pupal weight and showed reduced time to pupation when reared on the MYB134 overexpressing poplar. These results were unexpected since enhanced condensed tannin levels were predicted to act as feeding deterrents. However, the data may be explained by the observed decrease in the salicinoids (phenolic glycosides) salicortin and tremulacin that accompanied the upregulation of the condensed tannins in the transgenics. We conclude that for these two lepidopteran species, condensed tannin levels are unlikely to be a major determinant of caterpillar food preference or performance. However, our experiments show that overexpression of a single regulatory gene in transgenic aspen can have a significant impact on herbivorous insects.
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Affiliation(s)
- G Andreas Boeckler
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Strasse 8, 07745, Jena, Germany
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36
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Irmisch S, Clavijo McCormick A, Boeckler GA, Schmidt A, Reichelt M, Schneider B, Block K, Schnitzler JP, Gershenzon J, Unsicker SB, Köllner TG. Two herbivore-induced cytochrome P450 enzymes CYP79D6 and CYP79D7 catalyze the formation of volatile aldoximes involved in poplar defense. Plant Cell 2013; 25:4737-54. [PMID: 24220631 PMCID: PMC3875747 DOI: 10.1105/tpc.113.118265] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/15/2013] [Accepted: 10/21/2013] [Indexed: 05/18/2023]
Abstract
Aldoximes are known as floral and vegetative plant volatiles but also as biosynthetic intermediates for other plant defense compounds. While the cytochrome P450 monooxygenases (CYP) from the CYP79 family forming aldoximes as biosynthetic intermediates have been intensively studied, little is known about the enzymology of volatile aldoxime formation. We characterized two P450 enzymes, CYP79D6v3 and CYP79D7v2, which are involved in herbivore-induced aldoxime formation in western balsam poplar (Populus trichocarpa). Heterologous expression in Saccharomyces cerevisiae revealed that both enzymes produce a mixture of different aldoximes. Knockdown lines of CYP79D6/7 in gray poplar (Populus × canescens) exhibited a decreased emission of aldoximes, nitriles, and alcohols, emphasizing that the CYP79s catalyze the first step in the formation of a complex volatile blend. Aldoxime emission was found to be restricted to herbivore-damaged leaves and is closely correlated with CYP79D6 and CYP79D7 gene expression. The semi-volatile phenylacetaldoxime decreased survival and weight gain of gypsy moth (Lymantria dispar) caterpillars, suggesting that aldoximes may be involved in direct defense. The wide distribution of volatile aldoximes throughout the plant kingdom and the presence of CYP79 genes in all sequenced genomes of angiosperms suggest that volatile formation mediated by CYP79s is a general phenomenon in the plant kingdom.
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Affiliation(s)
- Sandra Irmisch
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | | | | | - Axel Schmidt
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | | | - Bernd Schneider
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Katja Block
- Helmholtz Zentrum München, Institute of Biochemical Plant Pathology, Research Unit Environmental Simulation, 85764 Neuherberg, Germany
| | - Jörg-Peter Schnitzler
- Helmholtz Zentrum München, Institute of Biochemical Plant Pathology, Research Unit Environmental Simulation, 85764 Neuherberg, Germany
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Boeckler GA, Gershenzon J, Unsicker SB. Gypsy Moth Caterpillar Feeding has Only a Marginal Impact on Phenolic Compounds in Old-Growth Black Poplar. J Chem Ecol 2013; 39:1301-12. [DOI: 10.1007/s10886-013-0350-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 09/18/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
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Irmisch S, Unsicker SB, Gershenzon J, Köllner TG. Identification and characterization of CYP79D6v4, a cytochrome P450 enzyme producing aldoximes in black poplar (Populus nigra). Plant Signal Behav 2013; 8:e27640. [PMID: 24390071 PMCID: PMC4091388 DOI: 10.4161/psb.27640] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 12/23/2013] [Indexed: 05/21/2023]
Abstract
After herbivore feeding, poplar trees produce complex volatile blends containing terpenes, green leaf volatiles, aromatics, and nitrogen-containing compounds such as aldoximes and nitriles. It has been shown recently that volatile aldoximes released from gypsy moth (Lymantria dispar) caterpillar-damaged black poplar (Populus nigra) trees attract parasitoids that are caterpillar enemies. In western balsam poplar (P. trichocarpa), volatile aldoximes are produced by 2 P450 monooxygenases, CYP79D6v3 and CYP79D7v2. A gene fragment with high similarity to CYP79D6/7 was recently shown to be upregulated in herbivore-damaged leaves of P. nigra. In the present study we report the cloning and characterization of this gene, designated as CYP79D6v4. Recombinant CYP79D6v4 was able to convert different amino acids into the corresponding aldoximes, which were also found in the volatile blend of P. nigra. Thus, CYP79D6v4 is most likely involved in herbivore-induced aldoxime formation in black poplar.
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Clavijo McCormick A, Unsicker SB, Gershenzon J. The specificity of herbivore-induced plant volatiles in attracting herbivore enemies. Trends Plant Sci 2012; 17:303-10. [PMID: 22503606 DOI: 10.1016/j.tplants.2012.03.012] [Citation(s) in RCA: 257] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 03/19/2012] [Accepted: 03/19/2012] [Indexed: 05/18/2023]
Abstract
Plants respond to herbivore attack by emitting complex mixtures of volatile compounds that attract herbivore enemies, both predators and parasitoids. Here, we explore whether these mixtures provide significant value as information cues in herbivore enemy attraction. Our survey indicates that blends of volatiles released from damaged plants are frequently specific depending on the type of herbivore and its age, abundance and feeding guild. The sensory perception of plant volatiles by herbivore enemies is also specific, according to the latest evidence from studies of insect olfaction. Thus, enemies do exploit the detailed information provided by plant volatile mixtures in searching for their prey or hosts, but this varies with the diet breadth of the enemy.
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Affiliation(s)
- Andrea Clavijo McCormick
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Strasse 8, D-07745 Jena, Germany
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40
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Gutbrodt B, Dorn S, Unsicker SB, Mody K. Species-specific responses of herbivores to within-plant and environmentally mediated between-plant variability in plant chemistry. CHEMOECOLOGY 2012. [DOI: 10.1007/s00049-012-0102-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Junker RR, Gershenzon J, Unsicker SB. Floral odor bouquet loses its ant repellent properties after inhibition of terpene biosynthesis. J Chem Ecol 2011; 37:1323-31. [PMID: 22160332 DOI: 10.1007/s10886-011-0043-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 09/04/2011] [Accepted: 11/28/2011] [Indexed: 11/25/2022]
Abstract
In their natural environment, plants are synchronously confronted with mutualists and antagonists, and thus benefit from signals that contain messages for both functional groups of interaction partners. Floral scents are complex blends of volatiles of different chemical classes, including benzenoids and terpenoids. It has been hypothesized that benzenoids have evolved as pollinator attracting signals, while monoterpenoids serve as defensive compounds against antagonists. In order to test this hypothesis, we reduced terpene emission in flowers of Phlox paniculata with specific biosynthetic inhibitors and compared the responses of Lasius niger ants to natural and inhibited floral scent bouquets. While the natural odors were strongly repellent to ants, the bouquets with a reduced emission rate of terpenoids were not. The loss of the flowers' ability to repel ants could be attributed predominantly to reduced amounts of linalool, a monoterpene alcohol. Flying flower visitors, mainly hoverflies, did not discriminate between the two types of flowers in an outdoor experiment. Since individual compounds appear to be capable of either attracting pollinators or defending the flower from enemies, the complexity of floral scent bouquets may have evolved to allow flowers to respond to both mutualists and antagonists simultaneously.
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Affiliation(s)
- Robert R Junker
- Department Biology, Institute of Sensory Ecology, Heinrich-Heine-University of Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
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Mraja A, Unsicker SB, Reichelt M, Gershenzon J, Roscher C. Plant community diversity influences allocation to direct chemical defence in Plantago lanceolata. PLoS One 2011; 6:e28055. [PMID: 22174766 PMCID: PMC3235097 DOI: 10.1371/journal.pone.0028055] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 10/31/2011] [Indexed: 11/18/2022] Open
Abstract
Background Forecasting the consequences of accelerating rates of changes in biodiversity for ecosystem functioning requires a mechanistic understanding of the relationships between the structure of biological communities and variation in plant functional characteristics. So far, experimental data of how plant species diversity influences the investment of individual plants in direct chemical defences against herbivores and pathogens is lacking. Methodology/Principal Findings We used Plantago lanceolata as a model species in experimental grasslands differing in species richness and composition (Jena Experiment) to investigate foliar concentrations of the iridoid glycosides (IG), catalpol and its biosynthetic precursor aucubin. Total IG and aucubin concentrations decreased, while catalpol concentrations increased with increasing plant diversity in terms of species or functional group richness. Negative plant diversity effects on total IG and aucubin concentrations correlated with increasing specific leaf area of P. lanceolata, suggesting that greater allocation to light acquisition reduced the investment into these carbon-based defence components. In contrast, increasing leaf nitrogen concentrations best explained increasing concentrations of the biosynthetically more advanced IG, catalpol. Observed levels of leaf damage explained a significant proportion of variation in total IG and aucubin concentrations, but did not account for variance in catalpol concentrations. Conclusions/Significance Our results clearly show that plants growing in communities of varying species richness and composition differ in their defensive chemistry, which may modulate plant susceptibility to enemy attack and consequently their interactions with higher trophic level organisms.
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Affiliation(s)
- Anne Mraja
- Max Planck Institute for Chemical Ecology, Jena, Germany
- Max Planck Institute for Biogeochemistry, Jena, Germany
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43
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Boeckler GA, Gershenzon J, Unsicker SB. Phenolic glycosides of the Salicaceae and their role as anti-herbivore defenses. Phytochemistry 2011; 72:1497-509. [PMID: 21376356 DOI: 10.1016/j.phytochem.2011.01.038] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/26/2011] [Accepted: 01/28/2011] [Indexed: 05/21/2023]
Abstract
Since the 19th century the phytochemistry of the Salicaceae has been systematically investigated, initially for pharmaceutical and later for ecological reasons. The result of these efforts is a rich knowledge about the phenolic components, especially a series of glycosylated and esterified derivatives of salicyl alcohol known as "phenolic glycosides". These substances have received extensive attention with regard to their part in plant-herbivore interactions. The negative impact of phenolic glycosides on the performance of many generalist herbivores has been reported in numerous studies. Other more specialized feeders are less susceptible and have even been reported to sequester phenolic glycosides for their own defense. In this review, we attempt to summarize our current knowledge about the role of phenolic glycosides in mediating plant-herbivore interactions. As background, we first review what is known about their basic chemistry and occurrence in plants.
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Affiliation(s)
- G Andreas Boeckler
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Str. 8, 07745 Jena, Germany
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Danner H, Boeckler GA, Irmisch S, Yuan JS, Chen F, Gershenzon J, Unsicker SB, Köllner TG. Four terpene synthases produce major compounds of the gypsy moth feeding-induced volatile blend of Populus trichocarpa. Phytochemistry 2011; 72:897-908. [PMID: 21492885 DOI: 10.1016/j.phytochem.2011.03.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/11/2011] [Accepted: 03/15/2011] [Indexed: 05/05/2023]
Abstract
After herbivore damage, many plants increase their emission of volatile compounds, with terpenes usually comprising the major group of induced volatiles. Populus trichocarpa is the first woody species with a fully sequenced genome, enabling rapid molecular approaches towards characterization of volatile terpene biosynthesis in this and other poplar species. We identified and characterized four terpene synthases (PtTPS1-4) from P. trichocarpa which form major terpene compounds of the volatile blend induced by gypsy moth (Lymantria dispar) feeding. The enzymes were heterologously expressed and assayed with potential prenyl diphosphate substrates. PtTPS1 and PtTPS2 accepted only farnesyl diphosphate and produced (-)-germacrene D and (E,E)-α-farnesene as their major products, respectively. In contrast, PtTPS3 and PtTPS4 showed both mono- and sesquiterpene synthase activity. They produce the acyclic terpene alcohols linalool and nerolidol but exhibited opposite stereospecificity. qRT-PCR analysis revealed that the expression of the respective terpene synthase genes was induced after feeding of gypsy moth caterpillars. The TPS enzyme products may play important roles in indirect defense of poplar to herbivores and in mediating intra- and inter-plant signaling.
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Affiliation(s)
- Holger Danner
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - G Andreas Boeckler
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Sandra Irmisch
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Joshua S Yuan
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA
| | - Feng Chen
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA
| | - Jonathan Gershenzon
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Sybille B Unsicker
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Tobias G Köllner
- Max Planck Institute for Chemical Ecology, Department of Biochemistry, Hans-Knöll Straße 8, 07745 Jena, Germany
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Unsicker SB, Franzke A, Specht J, Köhler G, Linz J, Renker C, Stein C, Weisser WW. Plant species richness in montane grasslands affects the fitness of a generalist grasshopper species. Ecology 2010; 91:1083-91. [PMID: 20462122 DOI: 10.1890/09-0402.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Theory predicts negative effects of increasing plant diversity on the abundance of specialist insect herbivores, but little is known about how plant diversity affects the performance and abundance of generalist insect herbivores. We studied oviposition rates and offspring numbers in females of the generalist grasshopper Chorthippus parallelus that were collected in 15 montane grasslands in 2005 and 2007 along a gradient of plant species richness in central Germany. In addition to plant species richness, we determined evenness and plant community composition in the grasslands and measured aboveground plant biomass and other habitat variables such as leaf area index, vegetation height, and solar radiation. There was substantial variation among sites in grasshopper fecundity and the number of nymphs that hatched from the egg pods. Both fitness measures were positively influenced by plant species richness at the sites, while female fitness did not correlate with any of the other habitat parameters. Abundance of C. parallelus in the grasslands was positively correlated with plant species richness, plant community composition, and incident solar radiation of the sites. There were no phenological differences between grasshoppers from the different study sites. Our results suggest that decreasing biodiversity threatens the persistence not only of specialist, but also of generalist insect herbivores via a variety of mechanisms including a decrease in diversity of the generalists' food plants.
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Affiliation(s)
- Sybille B Unsicker
- Institute of Ecology, University of Jena, Dornburgerstrasse 159, 07743 Jena, Germany.
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Stein C, Unsicker SB, Kahmen A, Wagner M, Audorff V, Auge H, Prati D, Weisser WW. Impact of invertebrate herbivory in grasslands depends on plant species diversity. Ecology 2010; 91:1639-50. [DOI: 10.1890/09-0600.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kigathi RN, Unsicker SB, Reichelt M, Kesselmeier J, Gershenzon J, Weisser WW. Emission of volatile organic compounds after herbivory from Trifolium pratense (L.) under laboratory and field conditions. J Chem Ecol 2009; 35:1335-48. [PMID: 20013039 PMCID: PMC2797619 DOI: 10.1007/s10886-009-9716-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 11/16/2009] [Accepted: 11/18/2009] [Indexed: 10/31/2022]
Abstract
Plants emit a wide range of volatile organic compounds in response to damage by herbivores, and many of the compounds have been shown to attract the natural enemies of insect herbivores or serve for inter- and intra-plant communication. Most studies have focused on volatile emission in the laboratory while little is known about emission patterns in the field. We studied the emission of volatiles by Trifolium pratense (red clover) under both laboratory and field conditions. The emission of 24 compounds was quantified in the laboratory, of which eight showed increased emission rates after herbivory by Spodoptera littoralis caterpillars, including (E)-beta-ocimene, the most abundant compound, (Z)-beta-ocimene, linalool, (E)-beta-caryophyllene, (E,E)-alpha-farnesene, 4,8-dimethyl-1,3,7-nonatriene (DMNT), 1-octen-3-ol, and methyl salicylate (MeSA). While most of these compounds have been reported as herbivore-induced volatiles from a wide range of plant taxa, 1-octen-3-ol seems to be a characteristic volatile of legumes. In the field, T. pratense plants with varying herbivore damage growing in established grassland communities emitted only 13 detectable compounds, and the correlation between herbivore damage and volatile release was more variable than in the laboratory. For example, the emission of (E)-beta-ocimene, (Z)-beta-ocimene, and DMNT actually declined with damage, while decanal exhibited increased emission with increasing herbivory. Elevated light and temperature increased the emission of many compounds, but the differences in light and temperature conditions between the laboratory and the field could not account for the differences in emission profiles. Our results indicate that the release of volatiles from T. pratense plants in the field is likely to be influenced by additional biotic and abiotic factors not measured in this study. The elucidation of these factors may be important in understanding the physiological and ecological functions of volatiles in plants.
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Affiliation(s)
- Rose N Kigathi
- Institute of Ecology, Friedrich-Schiller-University of Jena, Dornburger Str. 159, 07743 Jena, Germany.
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Unsicker SB, Kunert G, Gershenzon J. Protective perfumes: the role of vegetative volatiles in plant defense against herbivores. Curr Opin Plant Biol 2009; 12:479-85. [PMID: 19467919 DOI: 10.1016/j.pbi.2009.04.001] [Citation(s) in RCA: 246] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 04/12/2009] [Indexed: 05/22/2023]
Abstract
Herbivore damage to leaves and other vegetative tissues often stimulates the emission of volatile compounds, suggesting that these substances have a role in plant defense. In fact, ample evidence has accumulated in the last few years indicating that volatiles from vegetative plant parts can directly repel herbivores, such as ovipositing butterflies and host-seeking aphids. Volatiles have also been demonstrated to protect plants by attracting herbivore enemies, such as parasitic wasps, predatory arthropods and possibly even insectivorous birds. Even below ground herbivory results in the release of volatiles that attract herbivore enemies. However, plant volatiles are also known to attract enemies of plants. Hence, to determine the true value of these substances in defense, more research is needed especially in natural communities with non-agricultural species.
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Affiliation(s)
- Sybille B Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
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Fontana A, Reichelt M, Hempel S, Gershenzon J, Unsicker SB. The effects of arbuscular mycorrhizal fungi on direct and indirect defense metabolites of Plantago lanceolata L. J Chem Ecol 2009; 35:833-43. [PMID: 19568812 PMCID: PMC2712616 DOI: 10.1007/s10886-009-9654-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/05/2009] [Accepted: 06/11/2009] [Indexed: 12/01/2022]
Abstract
Arbuscular mycorrhizal fungi can strongly influence the metabolism of their host plant, but their effect on plant defense mechanisms has not yet been thoroughly investigated. We studied how the principal direct defenses (iridoid glycosides) and indirect defenses (volatile organic compounds) of Plantago lanceolata L. are affected by insect herbivory and mechanical wounding. Volatile compounds were collected and quantified from mycorrhizal and non-mycorrhizal P. lanceolata plants that underwent three different treatments: 1) insect herbivory, 2) mechanical wounding, or 3) no damage. The iridoids aucubin and catalpol were extracted and quantified from the same plants. Emission of terpenoid volatiles was significantly higher after insect herbivory than after the other treatments. However, herbivore-damaged mycorrhizal plants emitted lower amounts of sesquiterpenes, but not monoterpenes, than herbivore-damaged non-mycorrhizal plants. In contrast, mycorrhizal infection increased the emission of the green leaf volatile (Z)-3-hexenyl acetate in untreated control plants, making it comparable to emission from mechanically wounded or herbivore-damaged plants whether or not they had mycorrhizal associates. Neither mycorrhization nor treatment had any influence on the levels of iridoid glycosides. Thus, mycorrhizal infection did not have any effect on the levels of direct defense compounds measured in P. lanceolata. However, the large decline in herbivore-induced sesquiterpene emission may have important implications for the indirect defense potential of this species.
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Affiliation(s)
- Anna Fontana
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Stefan Hempel
- Department of Soil Ecology, UFZ - Helmholtzcentre for Environmental Research, Theodor-Lieser-Straße 4, 06120 Halle (Saale), Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745 Jena, Germany
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll Straße 8, 07745 Jena, Germany
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Hempel S, Stein C, Unsicker SB, Renker C, Auge H, Weisser WW, Buscot F. Specific bottom-up effects of arbuscular mycorrhizal fungi across a plant-herbivore-parasitoid system. Oecologia 2009; 160:267-77. [PMID: 19219458 PMCID: PMC2757589 DOI: 10.1007/s00442-009-1294-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 01/19/2009] [Indexed: 10/30/2022]
Abstract
The majority of plants are involved in symbioses with arbuscular mycorrhizal fungi (AMF), and these associations are known to have a strong influence on the performance of both plants and insect herbivores. Little is known about the impact of AMF on complex trophic chains, although such effects are conceivable. In a greenhouse study we examined the effects of two AMF species, Glomus intraradices and G. mosseae on trophic interactions between the grass Phleum pratense, the aphid Rhopalosiphum padi, and the parasitic wasp Aphidius rhopalosiphi. Inoculation with AMF in our study system generally enhanced plant biomass (+5.2%) and decreased aphid population growth (-47%), but there were no fungal species-specific effects. When plants were infested with G. intraradices, the rate of parasitism in aphids increased by 140% relative to the G. mosseae and control treatment. When plants were associated with AMF, the developmental time of the parasitoids decreased by 4.3% and weight at eclosion increased by 23.8%. There were no clear effects of AMF on the concentration of nitrogen and phosphorus in plant foliage. Our study demonstrates that the effects of AMF go beyond a simple amelioration of the plants' nutritional status and involve rather more complex species-specific cascading effects of AMF in the food chain that have a strong impact not only on the performance of plants but also on higher trophic levels, such as herbivores and parasitoids.
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Affiliation(s)
- Stefan Hempel
- Department of Soil Ecology, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Straße 4, 06120 Halle, Germany
| | - Claudia Stein
- Department of Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Straße 4, 06120 Halle, Germany
| | - Sybille B. Unsicker
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Carsten Renker
- Department of Soil Ecology, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Straße 4, 06120 Halle, Germany
- Naturhistorisches Museum Mainz, Reichklarastraße 10, 55116 Mainz, Germany
| | - Harald Auge
- Department of Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Straße 4, 06120 Halle, Germany
| | - Wolfgang W. Weisser
- Institute for Ecology, Friedrich-Schiller-University Jena, Dornburger Straße 159, 07743 Jena, Germany
| | - François Buscot
- Department of Soil Ecology, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Straße 4, 06120 Halle, Germany
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