title: N-(18-hydroxylinolenoyl)-L-glutamine: a newly discovered analog of volicitin in Manduca sexta and its elicitor activity in plants.
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.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502, Japan, yoshinaga.naoko.5v@kyoto-u.ac.jp.
authors.forename: Naoko
authors.initials: N
authors.lastname: Yoshinaga
authors.forename: Chihiro
authors.initials: C
authors.lastname: Ishikawa
authors.forename: Irmgard
authors.initials: I
authors.lastname: Seidl-Adams
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bosak
authors.forename: Takako
authors.initials: T
authors.lastname: Aboshi
authors.forename: James H
authors.initials: JH
authors.lastname: Tumlinson
authors.forename: Naoki
authors.initials: N
authors.lastname: Mori
mesh_terms: D000818:Animals; D005973:Glutamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D060434:Herbivory; D008042:Linolenic Acids / Q000737:chemistry / Q000378:metabolism*; D018402:Manduca / Q000737:chemistry / Q000502:physiology*; D018521:Plant Physiological Phenomena; D010944:Plants / Q000737:chemistry; D036226:Seedlings / Q000502:physiology; D032323:Solanum melongena / Q000502:physiology; D014026:Nicotiana / Q000502:physiology; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism*; D003313:Zea mays / Q000502:physiology; D017962:alpha-Linolenic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism
chemical_list: D008042:Linolenic Acids; C475661:N-linolenoyl-L-glutamine; D055549:Volatile Organic Compounds; C419781:volicitin; D017962:alpha-Linolenic Acid; D005973:Glutamine