title: Methyl Jasmonate-Induced Monoterpenes in Scots Pine and Norway Spruce Tissues Affect Pine Weevil Orientation.
abstract: In large parts of Europe, insecticide-free measures for protecting conifer plants are desired to suppress damage by the pine weevil Hylobius abietis (L.). Treatment with methyl jasmonate (MeJA), a chemical elicitor already used in crop production, may enhance expression of chemical defenses in seedlings in conifer regenerations. However, in a previous experiment, MeJA treatment resulted in substantially better field protection for Scots pine (Pinus sylvestris L.) than for Norway spruce (Picea abies (L.) Karst.). Hypothesizing that the variations may be at least due partly to volatiles released by MeJA-treated seedlings and their effects on pine weevil orientation, we examined tissue extracts of seedlings (from the same batches as previously used) by two-dimensional GC-MS. We found that the MeJA treatment increased contents of the monoterpene (-)-β-pinene in phloem (the weevil's main target tissue) of both tree species, however, the (-)-β-pinene/(-)-α-pinene ratio increased more in the phloem of P. sylvestris. We also tested the attractiveness of individual monoterpenes found in conifer tissues (needles and phloem) for pine weevils using an arena with traps baited with single-substance dispensers and pine twigs. Trap catches were reduced when the pine material was combined with a dispenser releasing (-)-β-pinene, (+)-3-carene, (-)-bornyl acetate or 1,8-cineole. However, (-)-α-pinene did not have this effect. Thus, the greater field protection of MeJA-treated P. sylvestris seedlings may be due to the selective induction of increases in contents of the deterrent (-)-β-pinene, in contrast to strong increases in both non-deterrent (-)-α-pinene and the deterrent (-)-β-pinene in P. abies seedlings.
authors.affiliation: Department of Chemistry, Organic Chemistry, KTH Royal Institute of Technology, School of Chemical Science and Engineering, SE-100 44, Stockholm, Sweden. linalun@kth.se.
authors.forename: Lina
authors.identifier: http://orcid.org/0000-0003-2867-2004
authors.initials: L
authors.lastname: Lundborg
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, SE-750 07, Uppsala, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Nordlander
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, SE-750 07, Uppsala, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Björklund
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, SE-750 07, Uppsala, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Nordenhem
authors.affiliation: Department of Chemistry, Organic Chemistry, KTH Royal Institute of Technology, School of Chemical Science and Engineering, SE-100 44, Stockholm, Sweden.|Institute of Technology, Division of Organic Chemistry, Tartu University, 50411, Tartu, Estonia.
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Borg-Karlson
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism*; D007300:Insect Control / Q000379:methods; D039821:Monoterpenes / Q000032:analysis / Q000378:metabolism*; D009664:Norway; D054883:Oxylipins / Q000378:metabolism*; D028222:Picea / Q000737:chemistry / Q000469:parasitology / Q000502:physiology; D028201:Pinaceae / Q000737:chemistry / Q000469:parasitology* / Q000502:physiology*; D041605:Pinus sylvestris / Q000737:chemistry / Q000469:parasitology / Q000502:physiology; D036226:Seedlings / Q000737:chemistry / Q000469:parasitology / Q000502:physiology; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism; D048889:Weevils / Q000502:physiology*
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D039821:Monoterpenes; D054883:Oxylipins; D055549:Volatile Organic Compounds; C072239:methyl jasmonate
keywords: Enantiomers; Hylobius abietis; Methyl jasmonate; Monoterpenes; Picea abies; Pinus sylvestris