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Maruoka T, Shirai Y, Daimon T, Fujii R, Dannoura M, Seidl-Adams I, Mori N, Yoshinaga N. Knock-Out of ACY-1 Like Gene in Spodoptera litura Supports the Notion that FACs Improve Nitrogen Metabolism. J Chem Ecol 2024:10.1007/s10886-024-01512-y. [PMID: 38913104 DOI: 10.1007/s10886-024-01512-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/16/2024] [Accepted: 05/18/2024] [Indexed: 06/25/2024]
Abstract
Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and N-linolenoyl-L-glutamine were originally identified in the regurgitant of Spodoptera exigua larvae. These fatty acid amino acid conjugates (FACs) are known to be elicitors that induce plants to release volatile compounds which in turn attract natural enemies of the larvae such as parasitic wasps. FAC concentrations are regulated by enzymatic biosynthesis and hydrolysis in the intestine of Lepidoptera larvae. It has been proposed that FAC metabolism activates glutamine synthetase and plays an important role in nitrogen metabolism in larvae. In this study, we identified candidate genes encoding a FACs hydrolase in Spodoptera litura using genomic information of various related lepidopteran species in which FACs hydrolases have been reported. We analyzed the importance of FAC hydrolysis on caterpillar performance with CRISPR/Cas9 knock outs. Larvae of strains with an inactive FACs hydrolase excreted FACs in their feces. They absorbed 30% less nitrogen from the diet compared to WT caterpillars resulting in a reduction of their body weight of up to 40% compared to wild type caterpillars. These results suggest that the hydrolysis of FACs is an important metabolism for insects and that FACs are important for larval growth.
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Affiliation(s)
- Tsuyoshi Maruoka
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Yu Shirai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Takaaki Daimon
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Rei Fujii
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Masako Dannoura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | | | - Naoki Mori
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan.
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Kallure GS, Sahoo SS, Kale RS, Barvkar VT, Kontham R, Giri AP. Aminoacylase efficiently hydrolyses fatty acid amino acid conjugates of Helicoverpa armigera potentially to increase the pool of glutamine. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 165:104070. [PMID: 38176573 DOI: 10.1016/j.ibmb.2024.104070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/30/2023] [Accepted: 01/01/2024] [Indexed: 01/06/2024]
Abstract
One of the most prevalent bioactive molecules present in the oral secretion (OS) of lepidopteran insects is fatty acid amino acid conjugates (FACs). Insect dietary components have influence on the synthesis and retaining the pool of FACs in the OS. We noted differential and diet-specific accumulation of FACs in the OS of Helicoverpa armigera by using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Interestingly, we identified FACs hydrolyzing enzyme aminoacylase (HaACY) in the OS of H. armigera through proteomic analysis. Next, we have cloned, expressed, and purified active recombinant HaACY in the bacterial system. Recombinant HaACY hydrolyzes all the six identified FACs in the OS of H. armigera larvae fed on host and non-host plants and releases respective fatty acid and glutamine. In these six FACs, fatty acid moieties vary while amino acid glutamine was common. Glutamine obtained upon hydrolysis of FACs by HaACY might serve as an amino acid pool for insect growth and development. To understand the substrate choices of HaACY, we chemically synthesized, purified, and characterized all the six FACs. Interestingly, rHaACY also shows hydrolysis of synthetic FACs into respective fatty acid and glutamine. Our results underline the importance of diet on accumulation of FACs and role of aminoacylase(s) in regulating the level of FACs and glutamine.
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Affiliation(s)
- Gopal S Kallure
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Shubhranshu Shekhar Sahoo
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India; Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India
| | - Rutuja S Kale
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Vitthal T Barvkar
- Department of Botany, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India
| | - Ravindar Kontham
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India; Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India
| | - Ashok P Giri
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India.
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Kutty NN, Mishra M. Dynamic distress calls: volatile info chemicals induce and regulate defense responses during herbivory. FRONTIERS IN PLANT SCIENCE 2023; 14:1135000. [PMID: 37416879 PMCID: PMC10322200 DOI: 10.3389/fpls.2023.1135000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/10/2023] [Indexed: 07/08/2023]
Abstract
Plants are continuously threatened by a plethora of biotic stresses caused by microbes, pathogens, and pests, which often act as the major constraint in crop productivity. To overcome such attacks, plants have evolved with an array of constitutive and induced defense mechanisms- morphological, biochemical, and molecular. Volatile organic compounds (VOCs) are a class of specialized metabolites that are naturally emitted by plants and play an important role in plant communication and signaling. During herbivory and mechanical damage, plants also emit an exclusive blend of volatiles often referred to as herbivore-induced plant volatiles (HIPVs). The composition of this unique aroma bouquet is dependent upon the plant species, developmental stage, environment, and herbivore species. HIPVs emitted from infested and non-infested plant parts can prime plant defense responses by various mechanisms such as redox, systemic and jasmonate signaling, activation of mitogen-activated protein (MAP) kinases, and transcription factors; mediate histone modifications; and can also modulate the interactions with natural enemies via direct and indirect mechanisms. These specific volatile cues mediate allelopathic interactions leading to altered transcription of defense-related genes, viz., proteinase inhibitors, amylase inhibitors in neighboring plants, and enhanced levels of defense-related secondary metabolites like terpenoids and phenolic compounds. These factors act as deterrents to feeding insects, attract parasitoids, and provoke behavioral changes in plants and their neighboring species. This review presents an overview of the plasticity identified in HIPVs and their role as regulators of plant defense in Solanaceous plants. The selective emission of green leaf volatiles (GLVs) including hexanal and its derivatives, terpenes, methyl salicylate, and methyl jasmonate (MeJa) inducing direct and indirect defense responses during an attack from phloem-sucking and leaf-chewing pests is discussed. Furthermore, we also focus on the recent developments in the field of metabolic engineering focused on modulation of the volatile bouquet to improve plant defenses.
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Jones AC, Felton GW, Tumlinson JH. The dual function of elicitors and effectors from insects: reviewing the 'arms race' against plant defenses. PLANT MOLECULAR BIOLOGY 2022; 109:427-445. [PMID: 34618284 DOI: 10.1007/s11103-021-01203-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
This review provides an overview, analysis, and reflection on insect elicitors and effectors (particularly from oral secretions) in the context of the 'arms race' with host plants. Following injury by an insect herbivore, plants rapidly activate induced defenses that may directly or indirectly affect the insect. Such defense pathways are influenced by a multitude of factors; however, cues from the insect's oral secretions are perhaps the most well studied mediators of such plant responses. The relationship between plants and their insect herbivores is often termed an 'evolutionary arms race' of strategies for each organism to either overcome defenses or to avoid attack. However, these compounds that can elicit a plant defense response that is detrimental to the insect may also benefit the physiology or metabolism of an insect species. Indeed, several insect elicitors of plant defenses (such as the fatty acid-amino acid conjugate, volicitin) are known to enhance an insect's ability to obtain nutritionally important compounds from plant tissue. Here we re-examine the well-known elicitors and effectors from chewing insects to demonstrate not only our incomplete understanding of the specific biochemical and molecular cascades involved in these interactions but also to consider the role of these compounds for the insect species itself. Finally, this overview discusses opportunities for research in the field of plant-insect interactions by utilizing tools such as genomics and proteomics to integrate the future study of these interactions through ecological, physiological, and evolutionary disciplines.
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Affiliation(s)
- Anne C Jones
- Biological Sciences Department, Virginia Polytechnic State and University, Blacksburg, VA, USA.
| | - Gary W Felton
- Entomology Department, Pennsylvania State University, University Park, PA, USA
| | - James H Tumlinson
- Entomology Department, Pennsylvania State University, University Park, PA, USA
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Krempl C, Joußen N, Reichelt M, Kai M, Vogel H, Heckel DG. Consumption of gossypol increases fatty acid-amino acid conjugates in the cotton pests Helicoverpa armigera and Heliothis virescens. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2021; 108:e21843. [PMID: 34490676 DOI: 10.1002/arch.21843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/11/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Gossypol is a toxic sesquiterpene dimer produced by cotton plants which deters herbivory by insects and vertebrates. Two highly reactive aldehyde groups contribute to gossypol toxicity by cross-linking herbivore proteins. We identified another consequence of consuming gossypol in two insect pests of cotton: increased amounts of fatty acid-amino acid conjugates (FACs). Eight different FACs in the feces of larval Helicoverpa armigera and Heliothis virescens increased when larvae consumed artificial diet containing gossypol, but not a gossypol derivative lacking free aldehyde groups (SB-gossypol). FACs are produced by joining plant-derived fatty acids with amino acids of insect origin in the larval midgut tissue by an unknown conjugase, and translocated into the gut lumen by an unknown transporter. FACs are hydrolyzed back into fatty acids and amino acids by an aminoacylase (L-ACY-1) in the gut lumen. The equilibrium level of FACs in the lumen is determined by a balance between conjugation and hydrolysis, which may differ among species. When heterologously expressed, L-ACY-1 of H. armigera but not H. virescens was inhibited by gossypol; consistent with the excretion of more FACs in the feces by H. armigera. FACs are known to benefit the plant host by inducing anti-herbivore defensive responses, and have been hypothesized to benefit the herbivore by acting as a surfactant and increasing nitrogen uptake efficiency. Thus in addition to its direct toxic effects, gossypol may negatively impact insect nitrogen uptake efficiency and amplify the signal used by the plant to elicit release of volatile compounds that attract parasitoids.
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Affiliation(s)
- Corinna Krempl
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Nicole Joußen
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Marco Kai
- Research Group Mass Spectrometry and Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - David G Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
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6
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Noman A, Aqeel M, Islam W, Khalid N, Akhtar N, Qasim M, Yasin G, Hashem M, Alamri S, Al-Zoubi OM, Jalees MM, Al-Sadi A. Insects-plants-pathogens: Toxicity, dependence and defense dynamics. Toxicon 2021; 197:87-98. [PMID: 33848517 DOI: 10.1016/j.toxicon.2021.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/01/2021] [Accepted: 04/07/2021] [Indexed: 10/21/2022]
Abstract
In a natural ecosystem, the pathogen-plant-insect relationship has diverse implications for each other. The pathogens as well as insect-pests consume plant tissues as their feed that mostly results in damage. In turn, plant species have evolved specialized defense system to not only protect themselves but reduce the damage also. Such tripartite interactions involve toxicity, metabolic modulations, resistance etc. among all participants of interaction. These attributes result in selection pressure among participants. Coevolution of such traits reveals need to focus and unravel multiple hidden aspects of insect-plant-pathogen interactions. The definite modulations during plant responses to biotic stress and the operating defense network against herbivores are vital to research areas. Different types of plant pathogens and herbivores are tackled with various changes in plants, e.g. changes in genes expression, glucosinolate metabolism detoxification, signal transduction, cell wall modifications, Ca2+dependent signaling. It is essential to clarify which chemical in plants can work as a defense signal or weapon in plant-pathogen-herbivore interactions. In spite of increased knowledge regarding signal transduction pathways regulating growth-defense balance, much more is needed to unveil the coordination of growth rate with metabolic modulations in bi-trophic interactions. Here, we addressed plant-pathogen-insect interaction for toxicity as well as dependnce along with plant defense dynamics against pathogens and insects with broad range effects at the physio-biochemical and molecular level. We have reviewed interfaces in plant-pathogen-insect research to show pulsating regulation of plant immunity for attuning survival and ecological equilibrium. An improved understanding of the systematic foundation of growth-defense stability has vital repercussions for enhancing crop yield, including insights into uncoupling of host-parasite tradeoffs for ecological and environmental sustainability.
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Affiliation(s)
- Ali Noman
- Department of Botany, Government College University, Faisalabad, 38040, Pakistan.
| | - Muhammad Aqeel
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| | - Waqar Islam
- College of Geography, Fujian Normal University, Fuzhou, PR China
| | - Noreen Khalid
- Department of Botany, Government College Women University, Sialkot, Pakistan
| | - Noreen Akhtar
- Department of Botany, Government College for Women University, Faisalabad, Pakistan
| | - Muhammad Qasim
- Institute of Insect Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, PR China
| | - Ghulam Yasin
- Institute of Pure and Applied Biology, Bahau Din Zakria University Multan Pakistan, Pakistan
| | - Mohamed Hashem
- King Khalid University, College of Science, Department of Biology, Abha, 61413, Saudi Arabia; Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt.
| | - Saad Alamri
- King Khalid University, College of Science, Department of Biology, Abha, 61413, Saudi Arabia
| | | | - Muhammad Moazam Jalees
- Department of Microbiology, Cholistan University of Veterinary and Animal Sciences. Bahawalpur, Pakistan
| | - Abdullah Al-Sadi
- College of Agriculture and Marine Sciences, Sultan Qaboos University, Muscat. Sultanate of Oman, Oman
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7
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Weiss LC, Albada B, Becker SM, Meckelmann SW, Klein J, Meyer M, Schmitz OJ, Sommer U, Leo M, Zagermann J, Metzler-Nolte N, Tollrian R. Identification of Chaoborus kairomone chemicals that induce defences in Daphnia. Nat Chem Biol 2018; 14:1133-1139. [DOI: 10.1038/s41589-018-0164-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 10/11/2018] [Indexed: 11/09/2022]
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8
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Aljbory Z, Chen MS. Indirect plant defense against insect herbivores: a review. INSECT SCIENCE 2018; 25:2-23. [PMID: 28035791 DOI: 10.1111/1744-7917.12436] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/06/2016] [Accepted: 12/20/2016] [Indexed: 05/09/2023]
Abstract
Plants respond to herbivore attack by launching 2 types of defenses: direct defense and indirect defense. Direct defense includes all plant traits that increase the resistance of host plants to insect herbivores by affecting the physiology and/or behavior of the attackers. Indirect defense includes all traits that by themselves do not have significant direct impact on the attacking herbivores, but can attract natural enemies of the herbivores and thus reduce plant loss. When plants recognize herbivore-associated elicitors, they produce and release a blend of volatiles that can attract predators, parasites, and other natural enemies. Known herbivore-associated elicitors include fatty acid-amino acid conjugates, sulfur-containing fatty acids, fragments of cell walls, peptides, esters, and enzymes. Identified plant volatiles include terpenes, nitrogenous compounds, and indoles. In addition, constitive traits including extrafloral nectars, food bodies, and domatia can be further induced to higher levels and attract natural enemies as well as provide food and shelter to carnivores. A better understanding of indirect plant defense at global and componential levels via advanced high throughput technologies may lead to utilization of indirect defense in suppression of herbivore damage to plants.
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Affiliation(s)
- Zainab Aljbory
- Department of Entomology, Kansas State University, Manhattan, Kansas, USA
| | - Ming-Shun Chen
- Department of Entomology, Kansas State University, Manhattan, Kansas, USA
- Hard Winter Wheat Genetics Research Unit, USDA-ARS, Kansas State University, Manhattan, Kansas, USA
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9
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Cheng Q, Gu S, Liu Z, Wang CZ, Li X. Expressional divergence of the fatty acid-amino acid conjugate-hydrolyzing aminoacylase 1 (L-ACY-1) in Helicoverpa armigera and Helicoverpa assulta. Sci Rep 2017; 7:8721. [PMID: 28821781 PMCID: PMC5562920 DOI: 10.1038/s41598-017-09185-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 07/24/2017] [Indexed: 12/25/2022] Open
Abstract
How FACs-producing generalist and specialist herbivores regulate their FACs-hydrolyzing enzyme L-ACY-1 to balance FACs’ beneficial vs. detrimental effects remains unknown. To address this question, we compared L-ACY-1 expression in Helicoverpa armigera and Helicoverpa assulta, a pair of closely related sibling species differing mainly in their host range, by the same sets of hostplants, protein to digestible carbohydrate (P:C) ratios, or allelochemical. L-ACY-1 expression remained low/unchanged in H. armigera, but was induced by hot pepper fruits and repressed by cotton bolls in H. assulta. The representative allelochemicals of the tested hostplants significantly (capsaicin) or insignificantly (gossypol and nicotine) induced L-ACY-1 expression in H. armigera, but insignificantly inhibited (capsaicin and gossypol) or induced (nicotine) it in H. assulta. L-ACY-1 expression remained low/unaltered on balanced (P50:C50 and P53:C47) or protein-biased diets and induced on carbohydrate-biased diets in H. armigera, but was at the highest level on balanced diets and reduced on either protein- or carbohydrate-biased diets in H. assulta. Furthermore, L-ACY-1 expression was significantly higher in H. assulta than in H. armigera for most of feeding treatments. Such expressional divergences suggest that FACs are utilized mainly for removal of excessive nitrogen in generalists but for nitrogen assimilation in specialists.
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Affiliation(s)
- Qian Cheng
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Shaohua Gu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zewen Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, the Chinese Academy of Sciences, Beijing, 100101, China
| | - Xianchun Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China. .,Department of Entomology and BIO5 Institute, The University of Arizona, Tucson, 85721, AZ, USA.
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10
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Yoshinaga N. Physiological function and ecological aspects of fatty acid-amino acid conjugates in insects†. Biosci Biotechnol Biochem 2016; 80:1274-82. [DOI: 10.1080/09168451.2016.1153956] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Abstract
In tritrophic interactions, plants recognize herbivore-produced elicitors and release a blend of volatile compounds (VOCs), which work as chemical cues for parasitoids or predators to locate their hosts. From detection of elicitors to VOC emissions, plants utilize sophisticated systems that resemble the plant–microbe interaction system. Fatty acid–amino acid conjugates (FACs), a class of insect elicitors, resemble compounds synthesized by microbes in nature. Recent evidence suggests that the recognition of insect elicitors by an ancestral microbe-associated defense system may be the origin of tritrophic interactions mediated by FACs. Here we discuss our findings in light of how plants have customized this defense to be effective against insect herbivores, and how some insects have successfully adapted to these defenses.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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11
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Murakami S, Nakata R, Aboshi T, Yoshinaga N, Teraishi M, Okumoto Y, Ishihara A, Morisaka H, Huffaker A, Schmelz EA, Mori N. Insect-induced daidzein, formononetin and their conjugates in soybean leaves. Metabolites 2014; 4:532-46. [PMID: 25000357 PMCID: PMC4192678 DOI: 10.3390/metabo4030532] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/23/2014] [Accepted: 06/24/2014] [Indexed: 01/14/2023] Open
Abstract
In response to attack by bacterial pathogens, soybean (Gylcine max) leaves accumulate isoflavone aglucones, isoflavone glucosides, and glyceollins. In contrast to pathogens, the dynamics of related insect-inducible metabolites in soybean leaves remain poorly understood. In this study, we analyzed the biochemical responses of soybean leaves to Spodoptera litura (Lepidoptera: Noctuidae) herbivory and also S. litura gut contents, which contain oral secretion elicitors. Following S. litura herbivory, soybean leaves displayed an induced accumulation of the flavone and isoflavone aglycones 4’,7-dihyroxyflavone, daidzein, and formononetin, and also the isoflavone glucoside daidzin. Interestingly, foliar application of S. litura oral secretions also elicited the accumulation of isoflavone aglycones (daidzein and formononetin), isoflavone 7-O-glucosides (daidzin, ononin), and isoflavone 7-O-(6’-O-malonyl-β-glucosides) (malonyldaidzin, malonylononin). Consistent with the up-regulation of the isoflavonoid biosynthetic pathway, folair phenylalanine levels also increased following oral secretion treatment. To establish that these metabolitic changes were the result of de novo biosynthesis, we demonstrated that labeled (13C9) phenylalanine was incorporated into the isoflavone aglucones. These results are consistent with the presence of soybean defense elicitors in S. litura oral secretions. We demonstrate that isoflavone aglycones and isoflavone conjugates are induced in soybean leaves, not only by pathogens as previously demonstrated, but also by foliar insect herbivory.
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Affiliation(s)
- Shinichiro Murakami
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Ryu Nakata
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Takako Aboshi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Naoko Yoshinaga
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Masayoshi Teraishi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Yutaka Okumoto
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Atsushi Ishihara
- Department of Agriculture, Tottori University, Koyama-machi 4-101, Tottori 680-8550, Japan.
| | - Hironobu Morisaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
| | - Alisa Huffaker
- Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, USDA, 1600 S.W. 23RD Drive, Gainesville, FL 32606, USA.
| | - Eric A Schmelz
- Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, USDA, 1600 S.W. 23RD Drive, Gainesville, FL 32606, USA.
| | - Naoki Mori
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan.
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12
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Yoshinaga N, Sawada Y, Nishida R, Kuwahara Y, Mori N. Specific Incorporation ofL-Glutamine into Volicitin in the Regurgitant ofSpodoptera litura. Biosci Biotechnol Biochem 2014; 67:2655-7. [PMID: 14730148 DOI: 10.1271/bbb.67.2655] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Volicitin, [N-(17-hydroxylinolenoyl)-L-glutamine], was identified as an elicitor of plant volatiles from a Spodoptera exigua regurgitant. It has been proposed that gut microbes synthesize volicitin from glutamine, a predominant amino acid component in the insect gut. However, we found that glutamine was not a major component in the regurgitant of Spodoptera litura, although L-glutamine was exclusively incorporated into volicitin by S. litura fed on diets enriched with various amino acids. This selectivity of glutamine as a substrate was not due to a dominant occurrence in the insect gut.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Japan
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Yoshinaga N, Ishikawa C, Seidl-Adams I, Bosak E, Aboshi T, Tumlinson JH, Mori N. N-(18-hydroxylinolenoyl)-L-glutamine: a newly discovered analog of volicitin in Manduca sexta and its elicitor activity in plants. J Chem Ecol 2014; 40:484-90. [PMID: 24817386 DOI: 10.1007/s10886-014-0436-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 04/13/2014] [Accepted: 04/22/2014] [Indexed: 10/25/2022]
Abstract
Plants attacked by insect herbivores release a blend of volatile organic compounds (VOCs) that serve as chemical cues for host location by parasitic wasps, natural enemies of the herbivores. Volicitin, N-(17-hydroxylinolenoyl)-L-glutamine, is one of the most active VOC elicitors found in herbivore regurgitants. Our previous study revealed that hydroxylation on the 17th position of the linolenic acid moiety of N-linolenoyl-L-glutamine increases by more than three times the elicitor activity in corn plants. Here, we identified N-(18-hydroxylinolenoyl)-L-glutamine (18OH-volicitin) from larval gut contents of tobacco hornworm (THW), Manduca sexta. Eggplant and tobacco, two solanaceous host plants of THW larvae, and corn, a non-host plant, responded differently to this new elicitor. Eggplant and tobacco seedlings emitted twice the amount of VOCs when 18OH-volicitin was applied to damaged leaf surfaces compared to N-linolenoyl-L-glutamine, while both these fatty acid amino acid conjugates (FACs) elicited a similar response in corn seedlings. In both solanaceous plants, there was no significant difference in the elicitor activity of 17OH- and 18OH-volicitin. Interestingly, other lepidopteran species that have 17OH-type volicitin also attack solanaceous plants. These data suggest that plants have developed herbivory-detection systems customized to their herbivorous enemies.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan,
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14
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Yoshinaga N, Abe H, Morita S, Yoshida T, Aboshi T, Fukui M, Tumlinson JH, Mori N. Plant volatile eliciting FACs in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance? Front Physiol 2014; 5:121. [PMID: 24744735 PMCID: PMC3978339 DOI: 10.3389/fphys.2014.00121] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 03/13/2014] [Indexed: 12/02/2022] Open
Abstract
Fatty acid amino acid conjugates (FACs), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of FAC analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of FACs is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of FACs is also unclear. In this study, the biosynthesis of FACs was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo FAC patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that FACs in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - Hiroaki Abe
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - Sayo Morita
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - Tetsuya Yoshida
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - Takako Aboshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - Masao Fukui
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
| | - James H Tumlinson
- Department of Entomology, Center for Chemical Ecology, Pennsylvania State University University Park, PA, USA
| | - Naoki Mori
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Sakyo, Kyoto, Japan
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15
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Erb M, Meldau S, Howe GA. Role of phytohormones in insect-specific plant reactions. TRENDS IN PLANT SCIENCE 2012; 17:250-9. [PMID: 22305233 PMCID: PMC3346861 DOI: 10.1016/j.tplants.2012.01.003] [Citation(s) in RCA: 506] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/20/2011] [Accepted: 01/05/2012] [Indexed: 05/17/2023]
Abstract
The capacity to perceive and respond is integral to biological immune systems, but to what extent can plants specifically recognize and respond to insects? Recent findings suggest that plants possess surveillance systems that are able to detect general patterns of cellular damage as well as highly specific herbivore-associated cues. The jasmonate (JA) pathway has emerged as the major signaling cassette that integrates information perceived at the plant-insect interface into broad-spectrum defense responses. Specificity can be achieved via JA-independent processes and spatio-temporal changes of JA-modulating hormones, including ethylene (ET), salicylic acid (SA), abscisic acid (ABA), auxin, cytokinins (CK), brassinosteroids (BR) and gibberellins (GB). The identification of receptors and ligands and an integrative view of hormone-mediated response systems are crucial to understand specificity in plant immunity to herbivores.
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Affiliation(s)
- Matthias Erb
- Root-Herbivore Interactions Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany.
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16
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Tian D, Peiffer M, Shoemaker E, Tooker J, Haubruge E, Francis F, Luthe DS, Felton GW. Salivary glucose oxidase from caterpillars mediates the induction of rapid and delayed-induced defenses in the tomato plant. PLoS One 2012; 7:e36168. [PMID: 22558369 PMCID: PMC3340365 DOI: 10.1371/journal.pone.0036168] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 04/02/2012] [Indexed: 01/09/2023] Open
Abstract
Caterpillars produce oral secretions that may serve as cues to elicit plant defenses, but in other cases these secretions have been shown to suppress plant defenses. Ongoing work in our laboratory has focused on the salivary secretions of the tomato fruitworm, Helicoverpa zea. In previous studies we have shown that saliva and its principal component glucose oxidase acts as an effector by suppressing defenses in tobacco. In this current study, we report that saliva elicits a burst of jasmonic acid (JA) and the induction of late responding defense genes such as proteinase inhibitor 2 (Pin2). Transcripts encoding early response genes associated with the JA pathway were not affected by saliva. We also observed a delayed response to saliva with increased densities of Type VI glandular trichomes in newly emerged leaves. Proteomic analysis of saliva revealed glucose oxidase (GOX) was the most abundant protein identified and we confirmed that it plays a primary role in the induction of defenses in tomato. These results suggest that the recognition of GOX in tomato may represent a case for effector-triggered immunity. Examination of saliva from other caterpillar species indicates that saliva from the noctuids Spodoptera exigua and Heliothis virescens also induced Pin2 transcripts.
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Affiliation(s)
- Donglan Tian
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
| | - Michelle Peiffer
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
| | - Erica Shoemaker
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
| | - John Tooker
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
| | - Eric Haubruge
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Liege, Belgium
| | - Frederic Francis
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Liege, Belgium
| | - Dawn S. Luthe
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
- Department of Crop and Soil Science, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
| | - Gary W. Felton
- Department of Entomology, Center for Chemical Ecology, Penn State University, University Park, Pennsylvania, United States of America
- * E-mail:
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17
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Kuhns EH, Seidl-Adams I, Tumlinson JH. Heliothine caterpillars differ in abundance of a gut lumen aminoacylase (L-ACY-1)-Suggesting a relationship between host preference and fatty acid amino acid conjugate metabolism. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:408-412. [PMID: 22266147 DOI: 10.1016/j.jinsphys.2012.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 01/04/2012] [Accepted: 01/05/2012] [Indexed: 05/31/2023]
Abstract
Fatty acid amino acid conjugates (FACs) in the oral secretions of Lepidopteran larvae are responsible for eliciting plant defense responses. FACs are present despite fitness costs which suggests that they are important for larval survival. In previous work, an aminoacylase (L-ACY-1) was identified as the enzyme responsible for hydrolysis of FACs within the larvae gut. This gene is present in three related Heliothine species: Heliothis virescens, Helicoverpa zea, and Heliothis subflexa. Transcript levels in gut tissues are predictive of protein abundance and enzyme activity in the frass. H. zea has the least amount of L-ACY-1 present in gut tissue and frass, while H. virescens has intermediate protein levels and H. subflexa has the highest amount of L-ACY-1 in gut tissue as well as in frass samples. These species differ in their host range and protein intake targets, and recently, it has been shown that FACs, the substrates of L-ACY-1, are involved in nitrogen metabolism. The correlation between protein intake and degree of host range specialization suggests that this aminoacylase may allow specialized larvae to obtain nitrogen requirements despite limitations in diet heterogeneity.
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Affiliation(s)
- Emily H Kuhns
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA.
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18
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Kuhns EH, Seidl-Adams I, Tumlinson JH. A lepidopteran aminoacylase (L-ACY-1) in Heliothis virescens (Lepidoptera: Noctuidae) gut lumen hydrolyzes fatty acid-amino acid conjugates, elicitors of plant defense. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:32-40. [PMID: 22056272 DOI: 10.1016/j.ibmb.2011.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/04/2011] [Accepted: 10/17/2011] [Indexed: 05/31/2023]
Abstract
Fatty acid-amino acid conjugates (FACs) have been identified in Lepidopteran larvae as elicitors of plant defenses. Plant responses include the production of primary defense compounds and induction of secondary defense strategies including attraction of parasitoid wasps. These elicitors are present despite fitness costs, suggesting that they are important for the larvae's survival. In order to exploit FAC-mediated plant defense responses in agricultural settings, an understanding of FAC purpose and metabolism is crucial. To clarify their role, enzymes involved in this metabolism are being investigated. In this work a previously undiscovered FAC hydrolase was purified from Heliothis virescens frass by liquid chromatography and PAGE techniques and was identified as an aminoacylase-like protein (L-ACY-1) using MALDI-ToF/ToF and Edman sequencing. The full length gene was cloned and expressed in Escherichia coli and a polyclonal antibody against L-ACY-1 was made. L-ACY-1 was confirmed to be responsible for FAC hydrolysis activity through inhibition of N-linolenoyl-l-glutamine hydrolysis by titration with the polyclonal anti-L-ACY-1 antibody. L-ACY-1 activity is dependent on a divalent cation. This is the first time an aminoacylase has been described from an insect. L-ACY-1 appears to play a vastly different role in insects than ACYs do in mammals and may be involved in maintaining glutamine supplies for gut tissue metabolism. Identification of L-ACY-1, a FAC hydrolase, clarifies a previously uncharacterized portion of FAC metabolism.
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Affiliation(s)
- Emily H Kuhns
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA.
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19
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Kim J, Quaghebeur H, Felton GW. Reiterative and interruptive signaling in induced plant resistance to chewing insects. PHYTOCHEMISTRY 2011; 72:1624-1634. [PMID: 21549401 DOI: 10.1016/j.phytochem.2011.03.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 03/29/2011] [Accepted: 03/30/2011] [Indexed: 05/30/2023]
Abstract
Our understanding of induced resistance against herbivores has grown immeasurably during the last several decades. Based upon the emerging literature, we argue that induced resistance represents a continuum of phenotypes that is determined by the plant's ability to integrate multiple suites of signals of plant and herbivore origin. We present a model that illustrates the range of signals arising from early detection through herbivore feeding, and then through subsequent plant generations.
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Affiliation(s)
- Jinwon Kim
- Department of Entomology and Center for Chemical Ecology, Penn State University, University Park, PA 16802, USA
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20
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Lait CG, Lobaido MJ, Wiester AJ, Kossak S, Tumlinson JH. Comparative kinetics of fatty acid-amino acid conjugate elicitor biosynthesis by midgut tissue microsomes of Lepidopterous caterpillar larvae. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2010; 75:264-274. [PMID: 21104884 DOI: 10.1002/arch.20392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
N-Linolenoyl-L-glutamine is one of several structurally similar fatty acid-amino acid conjugate (FAC) elicitors found in the oral secretions of Lepidopterous caterpillars and its biosynthesis is catalyzed by membrane-associated alimentary tissue enzyme(s). FAC elicitors comprise 17-hydroxylated or non-hydroxylated linolenic acid coupled with L-glutamine or L-glutamate by an amide bond. We demonstrate in vitro biosynthesis of N-linolenoyl-L-glutamine by Manduca sexta, Heliothis virescens, and Helicoverpa zea tissue microsomes. Comparison of N-linolenoyl-L-glutamine biosynthesis kinetics for these species suggests that concurrent biosynthesis and hydrolysis contribute to proportions of FAC elicitors found in their oral secretions. The apparent K(m) values for coupling of sodium linolenate were 8.75±0.79, 14.3±3.7 and 20.7±3.4 mM and V(max) values were 2.92±0.14, 6.81±1.2 and 4.95±0.55 nmol/min/mg protein for H. zea, H. virescens and M. sexta, respectively. The K(m) values for coupling of L-glutamine were 10.5±0.26, 22.3±2.0 and 18.9±2.4 mM and V(max) values were 1.78±0.21, 3.71±0.50 and 2.49±0.41 nmol/min/mg of protein for H. zea, H. virescens and M. sexta, respectively.
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Affiliation(s)
- Cameron G Lait
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, Agricultural Sciences & Industries Building, University Park, PA 16802, USA.
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21
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Yoshinaga N, Alborn HT, Nakanishi T, Suckling DM, Nishida R, Tumlinson JH, Mori N. Fatty Acid-amino Acid Conjugates Diversification in Lepidopteran Caterpillars. J Chem Ecol 2010; 36:319-25. [DOI: 10.1007/s10886-010-9764-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 01/29/2010] [Accepted: 02/11/2010] [Indexed: 11/29/2022]
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22
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Wu J, Baldwin IT. Herbivory-induced signalling in plants: perception and action. PLANT, CELL & ENVIRONMENT 2009; 32:1161-74. [PMID: 19183291 DOI: 10.1111/j.1365-3040.2009.01943.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Plants and herbivores have been interacting for millions of years. Over time, plants have evolved mechanisms to defend against herbivore attacks. Herbivore-challenged plants reconfigure their metabolism to produce compounds that are toxic, repellant or anti-digestive for the herbivores. Some compounds are volatile signals that attract the predators of herbivores. All these responses are tightly regulated by a signalling network triggered by the plant's perception machinery. Several compounds that specifically elicit herbivory-induced responses in plants have been isolated from herbivore oral secretions and oviposition fluids. Elicitor perception is rapidly followed by cell membrane depolarization, calcium influx and mitogen-activated protein kinase (MAPK) activation; plants also elevate the concentrations of reactive oxygen and nitrogen species, and modulate phytohormone levels accordingly. In addition to these reactions in the herbivore-attacked regions of a leaf, defence responses are also mounted in unattacked parts of the attacked leaf and as well in unattacked leaves. In this review, we summarize recent progress in understanding how plants recognize herbivory, the involvement of several important signalling pathways that mediate the responses to herbivore attack and the signals that transduce local into systemic responses.
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Affiliation(s)
- Jianqiang Wu
- Max-Planck Institute for Chemical Ecology, Hans-Knöll Str. 8, Jena 07745, Germany
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23
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Diezel C, von Dahl CC, Gaquerel E, Baldwin IT. Different lepidopteran elicitors account for cross-talk in herbivory-induced phytohormone signaling. PLANT PHYSIOLOGY 2009; 150:1576-86. [PMID: 19458114 PMCID: PMC2705021 DOI: 10.1104/pp.109.139550] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Accepted: 05/14/2009] [Indexed: 05/19/2023]
Abstract
Salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and their interactions mediate plant responses to pathogen and herbivore attack. JA-SA and JA-ET cross-signaling are well studied, but little is known about SA-ET cross-signaling in plant-herbivore interactions. When the specialist herbivore tobacco hornworm (Manduca sexta) attacks Nicotiana attenuata, rapid and transient JA and ET bursts are elicited without significantly altering wound-induced SA levels. In contrast, attack from the generalist beet armyworm (Spodoptera exigua) results in comparatively lower JA and ET bursts, but amplified SA bursts. These phytohormone responses are mimicked when the species' larval oral secretions (OS(Se) and OS(Ms)) are added to puncture wounds. Fatty acid-amino acid conjugates elicit the JA and ET bursts, but not the SA burst. OS(Se) had enhanced glucose oxidase activity (but not beta-glucosidase activity), which was sufficient to elicit the SA burst and attenuate the JA and ET levels. It is known that SA antagonizes JA; glucose oxidase activity and associated hydrogen peroxide also antagonizes the ET burst. We examined the OS(Ms)-elicited SA burst in plants impaired in their ability to elicit JA (antisense [as]-lox3) and ET (inverted repeat [ir]-aco) bursts and perceive ET (35s-etr1b) after fatty acid-amino acid conjugate elicitation, which revealed that both ET and JA bursts antagonize the SA burst. Treating wild-type plants with ethephone and 1-methylcyclopropane confirmed these results and demonstrated the central role of the ET burst in suppressing the OS(Ms)-elicited SA burst. By suppressing the SA burst, the ET burst likely facilitates unfettered JA-mediated defense activation in response to herbivores that otherwise would elicit SA.
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Affiliation(s)
- Celia Diezel
- Department of Molecular Ecology, Max-Planck-Institute for Chemical Ecology, D-07745 Jena, Germany
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24
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Active role of fatty acid amino acid conjugates in nitrogen metabolism in Spodoptera litura larvae. Proc Natl Acad Sci U S A 2008; 105:18058-63. [PMID: 18997016 DOI: 10.1073/pnas.0809623105] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Since the first fatty acid amino acid conjugate (FAC) was isolated from regurgitant of Spodoptera exigua larvae in 1997 [volicitin: N-(17-hydroxylinolenoyl)-L-glutamine], their role as elicitors of induced responses in plants has been well documented. However, studies of the biosyntheses and the physiological role of FACs in the insect have been minimal. By using (14)C-labeled glutamine, glutamic acid, and linolenic acid in feeding studies of Spodoptera litura larvae, combined with tissue analyses, we found glutamine in the midgut cells to be a major source for biosynthesis of FACs. Furthermore, 20% of the glutamine moiety of FACs was derived from glutamic acid and ammonia through enzymatic reaction of glutamine synthetase (GS). To determine whether FACs improve GS productivity, we studied nitrogen assimilation efficiency of S. litura larvae fed on artificial diets containing (15)NH(4)Cl and glutamic acid. When the diet was enriched with linolenic acid, the nitrogen assimilation efficiency improved from 40% to >60%. In the lumen, the biosynthesized FACs are hydrolyzed to fatty acids and glutamine, which are reabsorbed into tissues and hemolymph. These results strongly suggested that FACs play an active role in nitrogen assimilation in Lepidoptera larva and that glutamine containing FACs in the gut lumen may function as a form of storage of glutamine, a key compound of nitrogen metabolism.
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25
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Felton GW, Tumlinson JH. Plant-insect dialogs: complex interactions at the plant-insect interface. CURRENT OPINION IN PLANT BIOLOGY 2008; 11:457-63. [PMID: 18657469 DOI: 10.1016/j.pbi.2008.07.001] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 06/24/2008] [Accepted: 07/01/2008] [Indexed: 05/08/2023]
Abstract
Although five different classes of insect herbivore-produced elicitors of plant volatiles have been identified, this is only a part of the complex, chemically mediated interactions between insect herbivores and their host plants. The defensive reactions of the plant, following physical injury by the herbivore, are influenced by a multitude of factors including, but not necessarily limited to, the elicitors and numerous other herbivore-associated molecules, as well as microbes on the plant surface that may alter plant defensive pathways. Ultimately, a thorough and accurate understanding of the chemical ecology of insect-plant interactions will require a more holistic approach, taking into consideration the ecological and physiological context in which a plant perceives and responds to herbivore-associated signals.
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Affiliation(s)
- Gary W Felton
- Department of Entomology, Center for Chemical Ecology, The Pennsylvania State University, University Park, PA 16802, United States.
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26
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Male-derived butterfly anti-aphrodisiac mediates induced indirect plant defense. Proc Natl Acad Sci U S A 2008; 105:10033-8. [PMID: 18626017 DOI: 10.1073/pnas.0707809105] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Plants can recruit parasitic wasps in response to egg deposition by herbivorous insects-a sophisticated indirect plant defense mechanism. Oviposition by the Large Cabbage White butterfly Pieris brassicae on Brussels sprout plants induces phytochemical changes that arrest the egg parasitoid Trichogramma brassicae. Here, we report the identification of an elicitor of such an oviposition-induced plant response. Eliciting activity was present in accessory gland secretions released by mated female butterflies during egg deposition. In contrast, gland secretions from virgin female butterflies were inactive. In the male ejaculate, P. brassicae females receive the anti-aphrodisiac benzyl cyanide (BC) that reduces the females' attractiveness for subsequent mating. We detected this pheromone in the accessory gland secretion released by mated female butterflies. When applied onto leaves, BC alone induced phytochemical changes that arrested females of the egg parasitoid. Microarray analyses revealed a similarity in induced plant responses that may explain the arrest of T. brassicae to egg-laden and BC-treated plants. Thus, a male-derived compound endangers the offspring of the butterfly by inducing plant defense. Recently, BC was shown to play a role in foraging behavior of T. brassicae, by acting as a cue to facilitate phoretic transport by mated female butterflies to oviposition sites. Our results suggest that the anti-aphrodisiac pheromone incurs fitness costs for the butterfly by both mediating phoretic behavior and inducing plant defense.
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27
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Abstract
Herbivorous insects use diverse feeding strategies to obtain nutrients from their host plants. Rather than acting as passive victims in these interactions, plants respond to herbivory with the production of toxins and defensive proteins that target physiological processes in the insect. Herbivore-challenged plants also emit volatiles that attract insect predators and bolster resistance to future threats. This highly dynamic form of immunity is initiated by the recognition of insect oral secretions and signals from injured plant cells. These initial cues are transmitted within the plant by signal transduction pathways that include calcium ion fluxes, phosphorylation cascades, and, in particular, the jasmonate pathway, which plays a central and conserved role in promoting resistance to a broad spectrum of insects. A detailed understanding of plant immunity to arthropod herbivores will provide new insights into basic mechanisms of chemical communication and plant-animal coevolution and may also facilitate new approaches to crop protection and improvement.
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Affiliation(s)
- Gregg A Howe
- Department of Energy-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
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28
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Vogel H, Kroymann J, Mitchell-Olds T. Different transcript patterns in response to specialist and generalist herbivores in the wild Arabidopsis relative Boechera divaricarpa. PLoS One 2007; 2:e1081. [PMID: 17957263 PMCID: PMC2031921 DOI: 10.1371/journal.pone.0001081] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Accepted: 10/09/2007] [Indexed: 12/02/2022] Open
Abstract
Background Plants defend themselves against herbivorous insects, utilizing both constitutive and inducible defenses. Induced defenses are controlled by several phytohormone-mediated signaling pathways. Here, we analyze transcriptional changes in the North American Arabidopsis relative Boechera divaricarpa in response to larval herbivory by the crucifer specialist lepidopteran Plutella xylostella (diamondback moth) and by the generalist lepidopteran Trichoplusia ni (cabbage semilooper), and compare them to wounding and exogenous phytohormone application. Methodology/Principal Findings We use a custom macroarray constructed from B. divaricarpa herbivory-regulated cDNAs identified by suppression subtractive hybridization and from known stress-responsive A. thaliana genes for transcript profiling after insect herbivory, wounding and in response to jasmonate, salicylate and ethylene. In addition, we introduce path analysis as a novel approach to analyze transcript profiles. Path analyses reveal that transcriptional responses to the crucifer specialist P. xylostella are primarily determined by direct effects of the ethylene and salicylate pathways, whereas responses to the generalist T. ni are influenced by the ethylene and jasmonate pathways. Wound-induced transcriptional changes are influenced by all three pathways, with jasmonate having the strongest effect. Conclusions/Significance Our results show that insect herbivory is distinct from simple mechanical plant damage, and that different lepidopteran herbivores elicit different transcriptional responses.
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Affiliation(s)
- Heiko Vogel
- Department of Genetics and Evolution, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Juergen Kroymann
- Department of Genetics and Evolution, Max Planck Institute for Chemical Ecology, Jena, Germany
- * To whom correspondence should be addressed. E-mail:
| | - Thomas Mitchell-Olds
- Department of Genetics and Evolution, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Biology, Duke University, Durham, North Carolina, United States of America
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Alborn HT, Hansen TV, Jones TH, Bennett DC, Tumlinson JH, Schmelz EA, Teal PEA. Disulfooxy fatty acids from the American bird grasshopper Schistocerca americana, elicitors of plant volatiles. Proc Natl Acad Sci U S A 2007; 104:12976-81. [PMID: 17664416 PMCID: PMC1941812 DOI: 10.1073/pnas.0705947104] [Citation(s) in RCA: 177] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A previously unidentified class of compounds has been isolated from the regurgitant of the grasshopper species Schistocerca americana. These compounds (named here "caeliferins") are composed of saturated and monounsaturated sulfated alpha-hydroxy fatty acids in which the omega-carbon is functionalized with either a sulfated hydroxyl or a carboxyl conjugated to glycine via an amide bond. The regurgitant contains a series of these compounds with fatty acid chains of 15-20 carbons and in varying proportions. Of these, the 16-carbon analogs are predominant and are also most active in inducing release of volatile organic compounds when applied to damaged leaves of corn seedlings. Caeliferins are nonlepidopteran elicitors identified in insect herbivores. This adds a category of insect herbivore-produced elicitors of plant responses, providing further evidence of the ability of plants to detect and respond to a broad range of insect herbivore-produced compounds.
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Affiliation(s)
- Hans T. Alborn
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
- To whom correspondence may be addressed. E-mail: or
| | - Trond V. Hansen
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - Tappey H. Jones
- Department of Chemistry, Virginia Military Institute, Lexington, VA 24450; and
| | - Derrick C. Bennett
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - James H. Tumlinson
- Department of Entomology, Center for Chemical Ecology, 111 Chemical Ecology Laboratory, University Park, PA 16802
- To whom correspondence may be addressed. E-mail: or
| | - Eric A. Schmelz
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
| | - Peter E. A. Teal
- *Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, 1600/1700 Southwest 23rd Drive, Gainesville, FL 32608
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30
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Yoshinaga N, Aboshi T, Ishikawa C, Fukui M, Shimoda M, Nishida R, Lait CG, Tumlinson JH, Mori N. Fatty Acid Amides, Previously Identified in Caterpillars, Found in the Cricket Teleogryllus taiwanemma and Fruit Fly Drosophila melanogaster Larvae. J Chem Ecol 2007; 33:1376-81. [PMID: 17566833 DOI: 10.1007/s10886-007-9321-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 05/24/2007] [Accepted: 05/31/2007] [Indexed: 10/23/2022]
Abstract
Fatty acid amides (FAAs) are known elicitors that induce plants to release volatile compounds that, in turn, attract foraging parasitoids. Since the discovery of volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] in the regurgitant of larval Spodoptera exigua, a series of related FAAs have been identified in several other species of lepidopteran caterpillars. We screened 13 non-lepidopteran insects for the presence of FAAs and found that these compounds were present in adults of two closely related cricket species, Teleogryllus taiwanemma and T. emma (Orthoptera: Gryllidae), and larvae of the fruit fly, Drosophila melanogaster (Diptera: Drosophilidae). When analyzed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF), the gut contents of both crickets had nearly identical FAA composition, the major FAAs comprising N-linolenoyl-L-glutamic acid and N-linoleoyl-L-glutamic acid. There were also two previously uncharacterized FAAs that were thought to be hydroxylated derivatives of these glutamic acid conjugates, based on their observed fragmentation patterns. In addition to these four FAAs containing glutamic acid, N-linolenoyl-L-glutamine and a small amount of volicitin were detected. In D. melanogaster, N-linolenoyl-L-glutamic acid and N-linoleoyl-L-glutamic acid were the major FAAs found in larval extracts, while hydroxylated glutamic acid conjugates, volicitin and N-linolenoyl-L-glutamine, were detected as trace components. Although these FAAs were not found in ten of the insects studied here, their identification in two additional orders of insects suggests that FAAs are more common than previously reported and may have physiological roles in a wide range of insects besides caterpillars.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan
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31
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Ping L, Büchler R, Mithöfer A, Svatos A, Spiteller D, Dettner K, Gmeiner S, Piel J, Schlott B, Boland W. A novel Dps-type protein from insect gut bacteria catalyses hydrolysis and synthesis of N-acyl amino acids. Environ Microbiol 2007; 9:1572-83. [PMID: 17504494 DOI: 10.1111/j.1462-2920.2007.01279.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A novel type of a microbial N-acyl amino acid hydrolase (AAH) from insect gut bacteria was purified, cloned and functionally characterized. The enzyme was obtained from Microbacterium arborescens SE14 isolated from the foregut of larvae of the generalist herbivore Spodoptera exigua. The substrates of AAH are N-acyl-glutamines previously reported to elicit plant defence reactions after introduction into the leaf during feeding. The isolated AAH catalyses the hydrolysis of the amide bond (K(m) = 36 micromol l(-1)) and, less efficient, the formation (K(m) = 3 mmol l(-1)) of the elicitor active N-acyl amino acids. The AAH from M. arborescens SE14 shows no homology to known fatty acyl amidases (EC 3.5.1.4) but belongs to the family of Dps proteins (DNA-binding protein from starved cell). In line with other DPS proteins AAH is a homododecamer (monomer 17 181 Da) and contains iron atoms (c. 1-16 iron atoms per subunit). Unlike genuine DPS proteins the enzyme does not significantly bind DNA. Amino acid hydrolase is the first member of the DPS family that catalyses the cleavage or formation of amide bonds. The participation of a microbial enzyme in the homeostasis of N-acyl-glutamines in the insect gut adds further complexity to the interaction between plants and their herbivores.
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Affiliation(s)
- Liyan Ping
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany
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32
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Engelberth J, Seidl-Adams I, Schultz JC, Tumlinson JH. Insect elicitors and exposure to green leafy volatiles differentially upregulate major octadecanoids and transcripts of 12-oxo phytodienoic acid reductases in Zea mays. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:707-16. [PMID: 17555278 DOI: 10.1094/mpmi-20-6-0707] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The induction of jasmonic acid (JA) is one of the major signaling events in plants in response to insect herbivore damage and leads to the activation of direct and indirect defensive measures. Green leafy volatiles, which constitute a major portion of volatile organic compounds, often are released in response to insect herbivore attack and have been shown to significantly activate JA production in exposed corn (Zea mays) seedlings, thereby priming these plants specifically against subsequent herbivore attack. To explore the factors determining the specificity of the octadecanoid signaling pathway in corn, we analyzed qualitative and quantitative changes in major octadecanoids. The time course and the amount of induced JA and 12-oxophytodienoic acid levels in corn seedlings were strikingly different after wounding, application of caterpillar regurgitant, or treatment with cis-3-hexenyl acetate (Z-3-6:AC). Exposure to Z-3-6:AC induced accumulation of transcripts encoded by three putative 12-oxophytodienoate10,11-reductase genes (ZmOPR1/2, ZmOPR5, and ZmOPR8). Although changes in ZmOPR5 RNAs were detected only after exposure to Z-3-6:AC, ZmOPR1/2 RNAs and ZmOPR8 RNAs also were abundant after treatment with crude regurgitant elicitor or mechanical damage. The physiological implications of these findings in the context of plant-insect interactions are discussed.
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Affiliation(s)
- Jürgen Engelberth
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA.
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33
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Aboshi T, Yoshinaga N, Noge K, Nishida R, Mori N. Efficient incorporation of unsaturated fatty acids into volicitin-related compounds in Spodoptera litura (Lepidoptera: Noctuidae). Biosci Biotechnol Biochem 2007; 71:607-10. [PMID: 17284824 DOI: 10.1271/bbb.60546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We introduced efficient incorporation of unsaturated fatty acids into volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and N-linolenoyl-L-glutamine, insect-derived elicitors of plant volatiles, in the common cutworms Spodoptera litura by the incubation of larval gut tissues with unsaturated (linolenic, linoleic, and oleic acids) or saturated fatty acids (palmitic and stearic acids) sodium salt, and L-[alpha-(15)N]glutamine.
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Affiliation(s)
- Takako Aboshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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34
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Sawada Y, Yoshinaga N, Fujisaki K, Nishida R, Kuwahara Y, Mori N. Absolute configuration of volicitin from the regurgitant of lepidopteran caterpillars and biological activity of volicitin-related compounds. Biosci Biotechnol Biochem 2006; 70:2185-90. [PMID: 16960380 DOI: 10.1271/bbb.60133] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and N-linolenoyl-L-glutamine are known as insect-produced plant volatile elicitors. The absolute configuration of the hydroxylinolenoyl moiety of volicitin from three noctuid species, Helicoverpa armigera, Mythimna separata and Spodoptera litura, was determined to be all 17S in high enantiomeric excess. When treated with 30 pmol of (17S)- and (17R)-volicitin, corn seedlings were induced to release volatiles, there being no significant difference in the amount released between the two isomers. On the other hand, N-linolenoyl-L-glutamine was only about 30% as active as volicitin. Among several synthesized N-linolenoylamino acid conjugates, only the L-glutamine conjugate induced the emission of volatile organic compounds. These results show that the L-glutamine moiety of volicitin played a more critical role than the hydroxyl moiety, although both moieties affected the elicitor activity inducing the release of volatiles.
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Affiliation(s)
- Yoshitsugu Sawada
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
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35
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Delphia CM, Mescher MC, Felton GW, De Moraes CM. The Role of Insect-Derived Cues in Eliciting Indirect Plant Defenses in Tobacco, Nicotiana tabacum. PLANT SIGNALING & BEHAVIOR 2006; 1:243-50. [PMID: 19516985 PMCID: PMC2634125 DOI: 10.4161/psb.1.5.3279] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Accepted: 08/09/2006] [Indexed: 05/08/2023]
Abstract
In response to insect feeding, plants release complex volatile blends that are important host-location cues for natural enemies of herbivores. These induced volatile responses are mediated by insect-derived cues and differ significantly from responses to mechanical wounding. To improve understanding of the cues that elicit plant volatile responses, we explored the effects of Heliothis virescens saliva on volatile induction in tobacco, Nicotiana tabacum, using an ablation technique that prevents the release of saliva from the labial glands during feeding. Plants damaged by intact caterpillars released 11 volatile compounds. Ablated caterpillars induced these same 11 compounds plus an additional eight. Of the 11 shared compounds, plants damaged by ablated caterpillars released greater quantities of six, most notably volatile nicotine, compared to plants damaged by intact caterpillars. We further investigated the effects of H. virescens oral secretions on volatile induction through the collection and application of caterpillar regurgitant and saliva to mechanically wounded plants. Plants treated with H. virescens regurgitant released significantly more volatile nicotine than plants treated with saliva or those damaged by intact caterpillars. Additionally, application of a mixture of saliva and regurgitant induced less volatile nicotine compared to treatment with regurgitant alone. Our results suggest that saliva has an inhibitory effect on plant volatile responses to H. virescens feeding and that insect-derived cues originating from both regurgitant and saliva may interact to elicit the volatile "signature" of H. virescens.
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Affiliation(s)
- Casey M Delphia
- Department of Entomology; The Pennsylvania State University; University Park, Pennsylvania USA
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36
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Dean JM, De Moraes CM. Effects of Genetic Modification on Herbivore-Induced Volatiles from Maize. J Chem Ecol 2006; 32:713-24. [PMID: 16718567 DOI: 10.1007/s10886-006-9040-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 12/06/2005] [Accepted: 12/30/2005] [Indexed: 10/24/2022]
Abstract
Large-scale implementation of transgenic crop varieties raises concerns about possible nontarget effects on other organisms. This study examines the effects of genetic modification on plant volatile production and its potential impact on arthropod population dynamics. We compared herbivore-induced volatile emissions from Bacillus thuringiensis Berliner (Bt) maize plants to those from a nontransformed isoline following exposure to various types of leaf damage. When equal numbers of Helicoverpa zea Boddie (Lepidoptera: Noctuidae) larvae fed on Bt and non-Bt maize, volatile emissions were significantly lower in the transgenic plants, which also exhibited less leaf damage. When damage levels were controlled by adding more larvae to Bt plants, the plants' volatile emissions increased but displayed significant differences from those of nontransgenic plants. Significantly higher amounts of linalool, beta-myrcene, and geranyl acetate were released from transgenic maize than from non-Bt plants. Manipulating the duration of feeding by individual larvae to produce similar damage patterns resulted in similar volatile profiles for Bt and non-Bt plants. Controlling damage levels more precisely by mechanically wounding leaves and applying larval regurgitant likewise resulted in similar emission patterns for Bt and non-Bt maize. Overall, changes in the herbivore-induced volatile profiles of Bt maize appeared to be a consequence of altered larval feeding behavior rather than of changes in biochemical plant defense pathways. The implications of these findings for understanding the impacts of plant-mediated cues on pest and natural enemy behavior in transgenic crop systems are discussed.
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Affiliation(s)
- Jennifer M Dean
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
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37
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Major IT, Constabel CP. Molecular analysis of poplar defense against herbivory: comparison of wound- and insect elicitor-induced gene expression. THE NEW PHYTOLOGIST 2006; 172:617-35. [PMID: 17096789 DOI: 10.1111/j.1469-8137.2006.01877.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In order to characterize defense responses of hybrid poplar (Populus trichocarpax P. deltoides), we profiled leaf transcript patterns elicited by wounding and by regurgitant from forest tent caterpillar (FTC; Malacosoma disstria), a Lepidopteran defoliator of poplars. Macroarrays were used to compare transcript profiles. Both FTC-regurgitant (FTC-R) and mechanical wounding with pliers elicited expression of a variety of genes, and for these genes our analysis indicated that these treatments induced qualitatively similar responses. Similarly, a comparison of responses of directly treated and systemically induced leaves indicated extensive overlap in the sets of induced genes. FTC-R was found to contain the insect-derived elicitor volicitin. The simulated herbivory treatments resulted in the induction of genes involved in poplar defense and secondary metabolism. We also identified wound-responsive genes with roles in primary metabolism, including a putative invertase, lipase, and acyl-activating enzyme; some of these genes may have roles in defense signaling. In addition, we found three unknown genes containing a ZIM motif which may represent novel transcription factors.
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Affiliation(s)
- Ian T Major
- Centre for Forest Biology and Department of Biology, University of Victoria, Stn CSC, PO Box 3020, Victoria, BC, V8W 3 N5, Canada
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38
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Paré PW, Farag MA, Krishnamachari V, Zhang H, Ryu CM, Kloepper JW. Elicitors and priming agents initiate plant defense responses. PHOTOSYNTHESIS RESEARCH 2005; 85:149-59. [PMID: 16075316 DOI: 10.1007/s11120-005-1001-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Accepted: 01/19/2005] [Indexed: 05/03/2023]
Abstract
Biotic elicitors produced by plant pathogens or herbivore pests rapidly activate a range of plant chemical defenses when translocated to plant tissue. The fatty acid conjugate volicitin has proven to be a robust elicitor model for studying herbivore-induced plant defense responses. Here we review the role of insect-derived volicitin (N-[17-hydroxylinolenoyl]-L-glutamine) as an authentic elicitor of defense responses, specifically as an activator of signal volatiles that attract natural enemies of herbivore pests. Comparisons are drawn between volicitin as an elicitor of plant defenses and two other classes of signaling molecules, C(6) green-leaf volatiles and C(4) bacterial volatiles that appear to prime plant defenses thereby enhancing the capacity to mobilize cellular defense responses when a plant is faced with herbivore or pathogen attack.
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Affiliation(s)
- Paul W Paré
- Chemistry & Biochemistry Department, Texas Tech University, Lubbock, 79409, USA.
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39
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Hilker M, Stein C, Schröder R, Varama M, Mumm R. Insect egg deposition induces defence responses inPinus sylvestris: characterisation of the elicitor. J Exp Biol 2005; 208:1849-54. [PMID: 15879065 DOI: 10.1242/jeb.01578] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYEgg deposition by the phytophagous sawfly Diprion pini L.(Hymenoptera, Diprionidae) is known to induce locally and systemically the emission of volatiles in Scots pine (Pinus sylvestris L.) that attract the egg parasitoid Chrysonotomyia ruforum Krausse(Hymenoptera, Eulophidae). The egg parasitoids kill the eggs and thus prevent damage to the plant from feeding sawfly larvae. The elicitor inducing the pine's response is known to be located in the oviduct secretion which the female sawfly applies to the eggs when inserting them into a slit in the pine needle using the sclerotized ovipositor valves. In this study we have characterized the elicitor. The elicitor was still active when isolated from the oviduct and applied directly to slits made in the pine needles. However,as soon as the oviduct secretion was dissolved in Aqua dest. and stored for 3 h at room temperature or kept frozen at -80°C, its activity was lost. In contrast, oviduct secretion kept its eliciting activity, when dissolved in Ringer solution (pH 7.2) both after storage at room temperature and after freezing. The activity of the elicitor vanished after treatment of the oviduct secretion with proteinase K, which destroyed all proteins. This suggests that the elicitor in the oviduct secretion is a peptide or protein, or a component bound to these. SDS-PAGE revealed a similar, but not identical protein pattern from hemolymph and oviduct secretion. Hemolymph itself has no eliciting effect. The elicitor in the oviduct secretion is only active when transferred to slit pine needles, since its application on undamaged needles did not induce the emission of attractive volatiles.
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Affiliation(s)
- Monika Hilker
- Institute of Biology, Freie Universität Berlin, Haderslebener Str. 9, D-12163 Berlin, Germany.
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40
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Gomez SK, Cox MM, Bede JC, Inoue K, Alborn HT, Tumlinson JH, Korth KL. Lepidopteran herbivory and oral factors induce transcripts encoding novel terpene synthases in Medicago truncatula. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2005; 58:114-127. [PMID: 15660362 DOI: 10.1002/arch.20037] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Terpenes are an important class of defense compounds that accumulate in plants after pathogen infection or arthropod injury. Sequences predicted to encode terpene synthases were selected from an expressed sequence tag (EST) database of Medicago truncatula. Four putative terpene synthase clones (MtTps1-MtTps4), originating from a chewing insect-damaged M. truncatula leaf cDNA library, were isolated. Transcript levels of each gene examined increased in response to artificial wounding, Spodoptera exigua herbivory, and treatment with volatile methyl jasmonate (meJA). Addition of S. exigua regurgitant to wound sites triggered transcript accumulation of MtTps1 and levels increased with higher concentrations of regurgitant. Furthermore, induction of MtTps1 occurred after application of N-linolenoyl-glutamate or N-linoleoyl-glutamate, factors found in lepidopteran regurgitant. Genomic DNA blots indicate that each of the putative proteins is encoded by a single-copy gene or a small gene family. Proteins encoded by MtTps3 and MtTps4 are imported into the soluble fraction of chloroplasts in in vitro assays, whereas proteins encoded by MtTps1 and MtTps2 are not imported into chloroplasts. Combined with sequence comparisons of multiple plant terpene synthases, the import data indicate that MtTps1 and MtTps2 likely encode sesquiterpene synthases and that MtTps3 and MtTps4 encode mono- or di-terpene synthases. In addition to serving as a valuable model legume species for genomic studies, M. truncatula should prove a valuable source of novel terpene-producing enzymes. Induction of wound-responsive genes by insect oral factors suggests that M. truncatula senses biotic damage through the presence of elicitors originating in the herbivore.
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Affiliation(s)
- Susana K Gomez
- Department of Plant Pathology, University of Arkansas, Fayetteville 72701, USA
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41
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Yoshinaga N, Morigaki N, Matsuda F, Nishida R, Mori N. In vitro biosynthesis of volicitin in Spodoptera litura. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:175-184. [PMID: 15681227 DOI: 10.1016/j.ibmb.2004.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 11/01/2004] [Accepted: 11/10/2004] [Indexed: 05/24/2023]
Abstract
Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and N-linolenoyl-L-glutamine, originally identified in the regurgitant of Spodoptera exigua, induce damaged corn leaves to release volatile compounds which enable parasitic wasps to locate host caterpillars. Here we demonstrate the in vitro biosynthesis of volicitin for the first time by using gut tissues of Spodoptera litura larvae, as well as N-linolenoyl-L-glutamine. When crop, midgut tissues, peritrophic membrane and gut contents isolated from S. litura were incubated with sodium linolenate and L-[alpha-15N] glutamine, not only 15N-labeled N-linolenoyl-L-glutamine but 15N-labeled volicitin was detected mainly in the midgut incubation by LCMS and LCMSMS analysis. In contrast, there were negligible amounts of the newly biosynthesized compounds in the gut content incubation. Furthermore, the microsomal fraction obtained from the gut tissues clearly showed specific incorporation of glutamine. This substrate selectivity accounts for the exclusive uptake of glutamine by fatty acid amides (FAAs) in the noctuid caterpillars, even though glutamine was not a major component in the regurgitant. Additionally, intensive chemical analyses revealed that more than 20% of glutamine in hemolymph was present as conjugates in gut contents. These results suggest that FAA compounds are actively synthesized by caterpillar tissues and might play important physiological role(s) in glutamine metabolism.
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Affiliation(s)
- Naoko Yoshinaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan
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42
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Tumlinson JH, Lait CG. Biosynthesis of fatty acid amide elicitors of plant volatiles by insect herbivores. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2005; 58:54-68. [PMID: 15660361 DOI: 10.1002/arch.20036] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Larvae of several species of Lepidoptera produce fatty acid amide elicitors that induce the plants on which they feed to synthesize and release volatile organic compounds. The volatiles released by the plants act as cues that aid in host location by natural enemies of the herbivorous larvae. The elicitors are synthesized in the larvae by enzymes embedded in the membranes of the crop and anterior midgut tissues. The fatty acid precursors of the elicitors are obtained from the plants on which the caterpillars feed, while the amino acid moieties appear to be obtained from pools within the insects. The fatty acid amide elicitors are rapidly hydrolyzed in the midgut and hindgut by enzymes in the gut lumen. The role of these fatty acid amides in caterpillar metabolism is not yet understood.
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Affiliation(s)
- James H Tumlinson
- Department of Entomology, The Pennsylvania State University, University Park 16802, USA.
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Voelckel C, Baldwin IT. Generalist and specialist lepidopteran larvae elicit different transcriptional responses in Nicotiana attenuata, which correlate with larval FAC profiles. Ecol Lett 2004. [DOI: 10.1111/j.1461-0248.2004.00633.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Roda A, Halitschke R, Steppuhn A, Baldwin IT. Individual variability in herbivore-specific elicitors from the plant's perspective. Mol Ecol 2004; 13:2421-33. [PMID: 15245414 DOI: 10.1111/j.1365-294x.2004.02260.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lepidopteran larvae oral secretions and regurgitant (R), which contain a plethora of potential elicitors, are known to dramatically change a plant's wound response. We demonstrate, with a detailed microarray and secondary metabolite analysis, that the two most abundant fatty acid-amino acid conjugates (FACs) in the R of the specialist herbivore Manduca sexta (Lepidoptera, Sphingidae) can account for all measured direct (trypsin proteinase inhibitor: TPI) and indirect (cis-alpha-bergamotene) defences, the endogenous jasmonic acid burst that elicits them, and 86% of the induced transcriptional changes (89% up and 83% down) in its native host Nicotiana attenuata and hence are necessary and sufficient for the Manduca-specific modulation of the wound response. FACs were not found in eggs, but detected in larvae of all instars after their first meal. FACs were found in all regions of the alimentary canal and in the frass, but did not occur in salivary or mandibular glands, extracts of which were not active in any assay. Individual larvae differed substantially in their FAC composition and two FAC chemotypes were discernible: N-linolenoyl-L-glutamine biased R and N-linolenoyl-L-glutamate biased R. We created synthetic blends of FACs to mimic these chemical phenotypes and determined whether plants respond differently to the different R chemotypes. Micorarray and TPI analysis revealed that plants do not differentiate. N. attenuata plants use FACs from feeding caterpillars to tailor their wound responses but do not use the variability in FAC ratios to recognize attack from an individual caterpillar.
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Affiliation(s)
- Amy Roda
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, Beutenberg Campus, D-07745, Jena, Germany
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De Moraes CM, Mescher MC. Biochemical crypsis in the avoidance of natural enemies by an insect herbivore. Proc Natl Acad Sci U S A 2004; 101:8993-7. [PMID: 15184664 PMCID: PMC428460 DOI: 10.1073/pnas.0403248101] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plant-herbivore interactions provide well studied examples of coevolution, but little is known about how such interactions are influenced by the third trophic level. Here we show that larvae of the specialized lepidopteran herbivore Heliothis subflexa reduce their vulnerability to natural enemies through adaptation to a remarkable and previously unknown feature of their host plant, Physalis angulata: The fruits of this plant lack linolenic acid (LA), which is required for the development of most insects. By overcoming this nutritional deficiency, H. subflexa larvae achieve numerous advantages. First, they gain near-exclusive access to a food resource: we demonstrate that closely related Heliothis virescens larvae cannot develop on P. angulata fruit unless the fruit are treated with LA. Second, they reduce their vulnerability to enemies: LA is a key component of volicitin, an elicitor of plant-volatile-signaling defenses. We demonstrate that volicitin is absent in the oral secretions of fruit-feeding caterpillars, that the volatile profiles of plants induced by fruit feeding differ from those induced by leaf feeding or by feeding on LA-treated fruit, and that the former are far less attractive to female Cardiochiles nigriceps parasitoids. Finally, they render themselves nutritionally unsuitable as hosts for enemies that require LA for their own development: we show that C. nigriceps larvae fail to develop within the bodies of fruit-feeding caterpillars but do develop in caterpillars feeding on LA-treated fruit. Thus, H. subflexa larvae not only overcome a serious dietary deficiency but also reduce their vulnerability to natural enemies through a form of "biochemical crypsis."
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Affiliation(s)
- Consuelo M De Moraes
- Department of Entomology, 535 ASI Building, Pennsylvania State University, University Park, PA 16801, USA.
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De Moraes CM, Schultz JC, Mescher MC, Tumlinson JH. Induced plant signaling and its implications for environmental sensing. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2004; 67:819-34. [PMID: 15192871 DOI: 10.1080/15287390490428288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The sophisticated chemical responses of plants to environmental stimuli have profound implications for the development of remote sensing systems. Recent advances in the investigation of these responses have demonstrated that plants can be developed as reliable reporters of numerous environmental stimuli including soil and water conditions, light levels, temperature, mechanical damage, insect feeding, exposure to pathogens--including those that affect animals and humans--and exposure to airborne chemicals. Researchers are just beginning to understand the full range of plant phenotypic responses to these and other stimuli. These responses often have measurable physiological and molecular components that are readily observed. Other responses (e.g., internal biochemical changes) are less readily assayed, although sensing devices are being developed. Plant volatile emission "signatures" are particularly promising modes of plant reporting that can provide highly specific information regarding a diverse range of environmental variables on short time scales, but new approaches are needed for sensing these responses remotely. Modern molecular techniques promise to allow us to refine plant sensing and reporting, greatly enhancing the potential utility of plants as "sentinels." Continued basic research aimed at characterizing the physiological, biochemical, and molecular responses of plants to environmental stimuli (including airborne chemicals, insects and pathogenic microbes) are essential to achieving that promise.
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Affiliation(s)
- Consuelo M De Moraes
- Department of Entomology, Pennsylvania State University, 535 AG Sciences and Industries, University Park, PA 16802, USA.
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Engelberth J, Alborn HT, Schmelz EA, Tumlinson JH. Airborne signals prime plants against insect herbivore attack. Proc Natl Acad Sci U S A 2004; 101:1781-5. [PMID: 14749516 PMCID: PMC341853 DOI: 10.1073/pnas.0308037100] [Citation(s) in RCA: 489] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Green leafy volatiles (GLV), six-carbon aldehydes, alcohols, and esters commonly emitted by plants in response to mechanical damage or herbivory, induced intact undamaged corn seedlings to rapidly produce jasmonic acid (JA) and emit sesquiterpenes. More importantly, corn seedlings previously exposed to GLV from neighboring plants produced significantly more JA and volatile sesquiterpenes when mechanically damaged and induced with caterpillar regurgitant than seedlings not exposed to GLV. The use of pure synthetic chemicals revealed that (Z)-3-hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate have nearly identical priming activity. Caterpillar-induced nocturnal volatiles, which are enriched in GLV, also exhibited a strong priming effect, inducing production of larger amounts of JA and release of greater quantities of volatile organic compounds after caterpillar regurgitant application. In contrast, GLV priming did not affect JA production induced by mechanical wounding alone. Thus, GLV specifically prime neighboring plants against impending herbivory by enhancing inducible chemical defense responses triggered during attack and may play a key role in plant-plant signaling and plant-insect interactions.
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Affiliation(s)
- Juergen Engelberth
- Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL 32608, USA
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Schmelz EA, Alborn HT, Engelberth J, Tumlinson JH. Nitrogen deficiency increases volicitin-induced volatile emission, jasmonic acid accumulation, and ethylene sensitivity in maize. PLANT PHYSIOLOGY 2003; 133:295-306. [PMID: 12970495 PMCID: PMC196606 DOI: 10.1104/pp.103.024174] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2003] [Revised: 04/24/2003] [Accepted: 06/02/2003] [Indexed: 05/22/2023]
Abstract
Insect herbivore-induced plant volatile emission and the subsequent attraction of natural enemies is facilitated by fatty acid-amino acid conjugate (FAC) elicitors, such as volicitin [N-(17-hydroxylinolenoyl)-L-glutamine], present in caterpillar oral secretions. Insect-induced jasmonic acid (JA) and ethylene (E) are believed to mediate the magnitude of this variable response. In maize (Zea mays) seedlings, we examined the interaction of volicitin, JA, and E on the induction of volatile emission at different levels of nitrogen (N) availability that are known to influence E sensitivity. N availability and volicitin-induced sesquiterpene emission are inversely related as maximal responses were elicited in N-deficient plants. Plants with low N availability demonstrated similar volatile responses to volicitin (1 nmol plant(-1)) and JA (100 nmol plant(-1)). In contrast, plants with medium N availability released much lower amounts of volicitin-induced sesquiterpenes compared with JA, suggesting an alteration in volicitin-induced JA levels. As predicted, low N plants exhibited greater sustained increases in wound- and volicitin-induced JA levels compared with medium N plants. N availability also altered volicitin-E interactions. In low N plants, E synergized volicitin-induced sesquiterpene and indole emission 4- to 12-fold, with significant interactions first detected at 10 nL L(-1) E. Medium N plants demonstrated greatly reduced volicitin-E interactions. Volicitin-induced sesquiterpene emission was increased by E and was decreased by pretreatment the E perception inhibitor 1-methylcyclopropene without alteration in volicitin-induced JA levels. N availability influences plant responses to insect-derived elicitors through changes in E sensitivity and E-independent JA kinetics.
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Affiliation(s)
- Eric A Schmelz
- Center of Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture, Agricultural Research Service, Gainesville, FL 32608, USA.
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Lait CG, Alborn HT, Teal PEA, Tumlinson JH. Rapid biosynthesis of N-linolenoyl-L-glutamine, an elicitor of plant volatiles, by membrane-associated enzyme(s) in Manduca sexta. Proc Natl Acad Sci U S A 2003; 100:7027-32. [PMID: 12773625 PMCID: PMC165824 DOI: 10.1073/pnas.1232474100] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In response to elicitors in the oral secretions of caterpillars, plants produce and release volatile chemicals that attract predators and parasitoids of the caterpillar while it feeds. The most prevalent elicitors are fatty acid amides consisting of 18-carbon polyunsaturated fatty acids coupled with l-glutamine. We demonstrate rapid CoA- and ATP-independent in vitro biosynthesis of the fatty acid amide elicitor, N-linolenoyl-l-glutamine, by microsomal fractions of several alimentary tissues in Manduca sexta. N-linolenoyl-l-glutamine is a structural analog of several other elicitors including volicitin, the first fatty acid amide elicitor identified in caterpillars. The enzyme(s) that catalyzed biosynthesis of N-linolenoyl-l-glutamine was localized within the integral membrane protein fraction extracted from microsomes by Triton X-114 detergent phase partitioning and had maximum activity at alkaline pH. We found no evidence suggesting microbial or tissue-independent biosynthesis of N-linolenoyl-l-glutamine in M. sexta. The in vitro biosynthesis of N-linolenoyl-l-glutamine by membrane-associated enzyme(s) in M. sexta represents direct evidence of fatty acid amide synthesis by caterpillar tissues.
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Affiliation(s)
- Cameron G Lait
- United States Department of Agriculture-Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, 1700 SW 23rd Drive, Gainesville, FL 32608, USA
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Aldrich JR, Bartelt RJ, Dickens JC, Knight AL, Light DM, Tumlinson JH. Insect chemical ecology research in the United States Department of Agriculture-Agricultural Research Service. PEST MANAGEMENT SCIENCE 2003; 59:777-787. [PMID: 12846329 DOI: 10.1002/ps.710] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This multi-author paper reviews current work by USDA-ARS scientists in the field of chemical ecology. Work with pheromones, the discovery and development of the codling moth kairomone, studies on insect-plant interactions and chemically mediated tritrophic plant-insect interactions have led to practical methods for control of important insect pests.
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Affiliation(s)
- Jeffrey R Aldrich
- USDA-ARS Chemicals Affecting Insect Behavior Laboratory, Agricultural Research Center-West, Beltsville, MD 20705, USA.
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