title: Extrafloral nectar secretion from wounds of Solanum dulcamara.
abstract: Plants usually close wounds rapidly to prevent infections and the loss of valuable resources such as assimilates(1). However, herbivore-inflicted wounds on the bittersweet nightshade Solanum dulcamara appear not to close completely and produce sugary wound secretions visible as droplets. Many plants across the plant kingdom secrete sugary nectar from extrafloral nectaries(2) to attract natural enemies of herbivores for indirect defence(3,4). As ants forage on wound edges of S. dulcamara in the field, we hypothesized that wound secretions are a form of extrafloral nectar (EFN). We show that, unlike EFN from known nectaries, wound secretions are neither associated with any specific structure nor restricted to certain locations. However, similar to EFN, they are jasmonate-inducible and the plant controls their chemical composition. Wound secretions are attractive for ants, and application of wound secretion mimics increases ant attraction and reduces herbivory on S. dulcamara plants in a natural population. In greenhouse experiments, we reveal that ants can defend S. dulcamara from two of its native herbivores, slugs and flea beetle larvae. Since nectar is defined by its ecological function as a sugary secretion involved in interactions with animals(5), such 'plant bleeding' could be a primitive mode of nectar secretion exemplifying an evolutionary origin of structured extrafloral nectaries.
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Lortzing
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.|Molecular Interaction Ecology, Institute of Water and Wetland Research, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands.
authors.forename: Onno W
authors.identifier: 0000-0001-5280-2265
authors.initials: OW
authors.lastname: Calf
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Marlene
authors.initials: M
authors.lastname: Böhlke
authors.affiliation: Applied Metabolome Analysis, Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Schwachtje
authors.affiliation: Applied Metabolome Analysis, Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kopka
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Geuß
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kosanke
authors.affiliation: Molecular Interaction Ecology, Institute of Water and Wetland Research, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands.|German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany.|Institute of Ecology, Friedrich Schiller University Jena, Dornburger-Strasse. 159, 07743 Jena, Germany.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: van Dam
authors.affiliation: Molecular Ecology, Dahlem Centre of Plant Sciences, Institute of Biology/Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Steppuhn
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D002633:Chemotaxis; D001517:Coleoptera / Q000254:growth & development; D060434:Herbivory; D007814:Larva / Q000254:growth & development; D057048:Plant Nectar / Q000737:chemistry / Q000378:metabolism*; D011235:Predatory Behavior; D032322:Solanum / Q000502:physiology*; D013559:Symbiosis
chemical_list: D057048:Plant Nectar