title: Glucosinolate-related glucosides in Alliaria petiolata: sources of variation in the plant and different metabolism in an adapted specialist herbivore, Pieris rapae.
abstract: Specialized metabolites in plants influence their interactions with other species, including herbivorous insects, which may adapt to tolerate defensive phytochemicals. The chemical arsenal of Alliaria petiolata (garlic mustard, Brassicaceae) includes the glucosinolate sinigrin and alliarinoside, a hydroxynitrile glucoside with defensive properties to glucosinolate-adapted specialists. To further our understanding of the chemical ecology of A. petiolata, which is spreading invasively in North America, we investigated the metabolite profile and here report a novel natural product, petiolatamide, which is structurally related to sinigrin. In an extensive study of North American populations of A. petiolata, we demonstrate that genetic population differences as well as developmental regulation contribute to variation in the leaf content of petiolatamide, alliarinoside, sinigrin, and a related glycoside. We furthermore demonstrate widely different metabolic fates of these metabolites after ingestion in the glucosinolate-adapted herbivore Pieris rapae, ranging from simple passage over metabolic conversion to sequestration. The differences in metabolic fate were influenced by plant β-glucosidases, insect-mediated degradation, and the specificity of the larval gut transport system mediating sequestration.
authors.affiliation: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, Denmark.
authors.forename: Tina
authors.initials: T
authors.lastname: Frisch
authors.forename: Niels
authors.initials: N
authors.lastname: Agerbirk
authors.forename: Samantha
authors.initials: S
authors.lastname: Davis
authors.forename: Don
authors.initials: D
authors.lastname: Cipollini
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Olsen
authors.forename: Mohammed Saddik
authors.initials: MS
authors.lastname: Motawia
authors.forename: Nanna
authors.initials: N
authors.lastname: Bjarnholt
authors.forename: Birger Lindberg
authors.initials: BL
authors.lastname: Møller
mesh_terms: D000818:Animals; D019607:Brassicaceae / Q000737:chemistry / Q000502:physiology*; D002080:Butterflies / Q000502:physiology*; D005960:Glucosides / Q000032:analysis / Q000378:metabolism*; D005961:Glucosinolates / Q000032:analysis / Q000378:metabolism*; D060434:Herbivory; D009570:Nitriles / Q000032:analysis / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000502:physiology
chemical_list: D005960:Glucosides; D005961:Glucosinolates; D009570:Nitriles; C430148:alliarinoside; C010330:sinigrin