title: The major volatile organic compound emitted from Arabidopsis thaliana flowers, the sesquiterpene (E)-β-caryophyllene, is a defense against a bacterial pathogen.
abstract: Flowers have a high risk of pathogen attack because of their rich nutrient and moisture content, and high frequency of insect visitors. We investigated the role of (E)-β-caryophyllene in floral defense against a microbial pathogen. This sesquiterpene is a common volatile compound emitted from flowers, and is a major volatile released from the stigma of Arabidopsis thaliana flowers. Arabidopsis thaliana lines lacking a functional (E)-β-caryophyllene synthase or constitutively overexpressing this gene were challenged with Pseudomonas syringae pv. tomato DC3000, which is a bacterial pathogen of brassicaceous plants. Flowers of plant lines lacking (E)-β-caryophyllene emission showed greater bacterial growth on their stigmas than did wild-type flowers, and their seeds were lighter and misshapen. By contrast, plant lines with ectopic (E)-β-caryophyllene emission from vegetative parts were more resistant than wild-type plants to pathogen infection of leaves, and showed reduced cell damage and higher seed production. Based on in vitro experiments, (E)-β-caryophyllene seems to act by direct inhibition of bacterial growth, rather than by triggering defense signaling pathways. (E)-β-Caryophyllene thus appears to serve as a defense against pathogens that invade floral tissues and, like other floral volatiles, may play multiple roles in defense and pollinator attraction.
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.|Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
authors.forename: Mengsu
authors.initials: M
authors.lastname: Huang
authors.affiliation: Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
authors.forename: Adela M
authors.initials: AM
authors.lastname: Sanchez-Moreiras
authors.affiliation: Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Abel
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Sohrabi
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Sungbeom
authors.initials: S
authors.lastname: Lee
authors.affiliation: Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Tholl
mesh_terms: D017360:Arabidopsis / Q000382:microbiology* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000382:microbiology / Q000502:physiology*; D054884:Host-Pathogen Interactions; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology*; D030821:Plants, Genetically Modified; D000081223:Polycyclic Sesquiterpenes; D044224:Pseudomonas syringae / Q000187:drug effects / Q000472:pathogenicity; D012639:Seeds / Q000378:metabolism / Q000382:microbiology; D012717:Sesquiterpenes / Q000378:metabolism* / Q000494:pharmacology*; D055549:Volatile Organic Compounds
chemical_list: D029681:Arabidopsis Proteins; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D055549:Volatile Organic Compounds; C024714:caryophyllene