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Research article - Peer-reviewed, 2020

Priming of inducible defenses protects Norway spruce against tree-killing bark beetles

Mageroy, Melissa H.; Christiansen, Erik; Langstrom, Bo; Borg-Karlson, Anna-Karin; Solheim, Halvor; Bjorklund, Niklas; Zhao, Tao; Schmidt, Axel; Fossdal, Carl Gunnar; Krokene, Paal


Plants can form an immunological memory known as defense priming, whereby exposure to a priming stimulus enables quicker or stronger response to subsequent attack by pests and pathogens. Such priming of inducible defenses provides increased protection and reduces allocation costs of defense. Defense priming has been widely studied for short-lived model plants such as Arabidopsis, but little is known about this phenomenon in long-lived plants like spruce. We compared the effects of pretreatment with sublethal fungal inoculations or application of the phytohormone methyl jasmonate (MeJA) on the resistance of 48-year-old Norway spruce (Picea abies) trees to mass attack by a tree-killing bark beetle beginning 35 days later. Bark beetles heavily infested and killed untreated trees but largely avoided fungus-inoculated trees and MeJA-treated trees. Quantification of defensive terpenes at the time of bark beetle attack showed fungal inoculation induced 91-fold higher terpene concentrations compared with untreated trees, whereas application of MeJA did not significantly increase terpenes. These results indicate that resistance in fungus-inoculated trees is a result of direct induction of defenses, whereas resistance in MeJA-treated trees is due to defense priming. This work extends our knowledge of defense priming from model plants to an ecologically important tree species.


defense priming; Ips typographus; methyl jasmonate; Picea abies; resistance

Published in

Plant, Cell and Environment
2020, volume: 43, number: 2, pages: 420-430
Publisher: WILEY

Authors' information

Mageroy, Melissa H.
Norwegian Inst Bioecon Res
Christiansen, Erik
Norwegian Inst Bioecon Res
Swedish University of Agricultural Sciences, Department of Ecology
Borg-Karlson, Anna-Karin
Royal Institute of Technology
Solheim, Halvor
Norwegian Inst Bioecon Res
Swedish University of Agricultural Sciences, Department of Ecology
Zhao, Tao
Orebro University
Schmidt, Axel
Max Planck Society
Fossdal, Carl Gunnar
Norwegian Inst Bioecon Res
Krokene, Paal
Norwegian Inst Bioecon Res

Associated SLU-program

SLU Network Plant Protection

UKÄ Subject classification

Biochemistry and Molecular Biology

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