title: Indole is an essential herbivore-induced volatile priming signal in maize.
abstract: Herbivore-induced volatile organic compounds prime non-attacked plant tissues to respond more strongly to subsequent attacks. However, the key volatiles that trigger this primed state remain largely unidentified. In maize, the release of the aromatic compound indole is herbivore-specific and occurs earlier than other induced responses. We therefore hypothesized that indole may be involved in airborne priming. Using indole-deficient mutants and synthetic indole dispensers, we show that herbivore-induced indole enhances the induction of defensive volatiles in neighbouring maize plants in a species-specific manner. Furthermore, the release of indole is essential for priming of mono- and homoterpenes in systemic leaves of attacked plants. Indole exposure markedly increases the herbivore-induced production of the stress hormones jasmonate-isoleucine conjugate and abscisic acid, which represents a likely mechanism for indole-dependent priming. These results demonstrate that indole functions as a rapid and potent aerial priming agent that prepares systemic tissues and neighbouring plants for incoming attacks.
authors: Institute of Plant Sciences, Department of Biology, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
authors: Matthias
authors: M
authors: Erb
authors: Laboratory for Fundamental and Applied Research in Chemical Ecology, Faculty of Science, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel, Switzerland.
authors: Nathalie
authors: N
authors: Veyrat
authors: Institute of Plant Sciences, Department of Biology, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
authors: Christelle A M
authors: CA
authors: Robert
authors: Laboratory for Fundamental and Applied Research in Chemical Ecology, Faculty of Science, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel, Switzerland.
authors: Hao
authors: H
authors: Xu
authors: Lehrstuhl für Genetik, TU Munich, Emil-Ramann-Straβe 8, 85354 Freising, Germany.
authors: Monika
authors: M
authors: Frey
authors: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, S10 2TN Sheffield, UK.
authors: Jurriaan
authors: J
authors: Ton
authors: Laboratory for Fundamental and Applied Research in Chemical Ecology, Faculty of Science, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel, Switzerland.
authors: Ted C J
authors: TC
authors: Turlings
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis; D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism; D060434:Herbivory / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology*; D009154:Mutation / Q000235:genetics; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology; D055549:Volatile Organic Compounds / Q000494:pharmacology*; D003313:Zea mays / Q000187:drug effects / Q000502:physiology*
chemical_list: D003517:Cyclopentanes; D007211:Indoles; D054883:Oxylipins; D010937:Plant Growth Regulators; D013729:Terpenes; D055549:Volatile Organic Compounds; C011006:jasmonic acid; D000040:Abscisic Acid; C030374:indole