Conifer chemical defense: Rugulation of bark beetle colonization and pheromone emission
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Terpenes and phenols are of importance in conifer defense against insects and pathogens. Knowledge about tree chemical defense is vital for developing practical methods to maintain healthy forests. With the aims of characterizing the defensive chemical induction in Norway spruce Picea abies and demonstrating its ecological function to spruce bark beetle Ips typographus, we measured the terpenoid and phenolic content in the bark of mature Norway spruce trees suffering windstorm, inoculated with Ceratocystis polonica, or treated with methyl jasmonate (MeJA), and investigated the colonization and pheromone emission of I. typographus.
All three stressors altered the chemical profile in the bark of Norway spruce. Trees damaged by windstorm had lower proportions of (+)-3-carene and two unidentified stilbenes, and a higher taxifolin glycoside content than trees without apparent windstorm damage; C. polonica inoculation induced extremely strong quantitative terpene accumulation in the wound reaction zone, but only increased the levels of (+)-3-carene, sabinene and terpinolene in the bark near the reaction zone; MeJA treatment generally elicited quantitative terpene accumulation, but the induction differed extensively between individual trees. In addition, logs from MeJA-treated tree showed much stronger wounding response compared to control logs.
The chemical profile of Norway spruce affected the colonization and pheromone emission of I. typographus. In response to fungal inoculation, terpene present in the reaction zone inhibited the colonization of I. typographus in a dose-dependent manner. Host defense elicited by MeJA treatment reduced emissions of 2-methyl-3-buten-2-ol and (S)-cis-verbenol, the two key aggregation pheromone components of I. typographus, and altered the ratio between the two components.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2011. , 75 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2011:16
Picea abies, Ips typographus, Ceratocystis polonica, methyl jasmonate, windstorm, stress response, terpenes, phenols, colonization, pheromone emission
IdentifiersURN: urn:nbn:se:kth:diva-33199ISBN: 978-91-7415-884-7OAI: oai:DiVA.org:kth-33199DiVA: diva2:413917
2011-05-23, sal F3, Lindstedtsvägen 26, KTH, Stockholm, 15:52 (English)
Valterova, Irena, Associate Professor
Borg-Karlson, Anna-Karin, Professor
QC 201105032011-05-032011-04-292011-05-03Bibliographically approved
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