Author/Editor		Novak, Metka; Urbanek Krajnc, Andreja; Lah, Ljerka; Zupanec, Neja; Kraševec, Nada; Križman, Mitja; Bohlmann, Joerg; Komel, Radovan
Title		Low-density Ceratocystis polonica inoculation of Norway spruce (Picea abies) triggers accumulation of monoterpenes with antifungal properties
Type		članek
Publication year		2013
ISSN		1612-4677 - European journal of forest research
Language		eng
Abstract		Among the most devastating pests of Norwayspruce (Picea abies) are the European spruce bark beetle(Ips typographus) and the associated pathogenic blue-stainfungus Ceratocystis polonica. Following attack and colonization,the beetle and the fungus must cope with inducedhost chemical defenses, such as monoterpenes that aregenerally thought to be toxic to both symbionts. The goalof this study was to better understand the response ofNorway spruce following C. polonica inoculation at lowdensity that does not overwhelm the tree and to identifymonoterpenes mobilized toward the fungus. We inoculatedhealthy mature trees and monitored monoterpene profiles 2,3, and 5 months post-inoculation. We also exposed three different C. polonica strains to the most abundant or significantlyup-regulated monoterpenes to determine differencesin monoterpene toxicity and resistance amongstrains. Total monoterpene levels, including limonene,were increased at 2 and 3 months after inoculation and haddropped after 5 months. In in vitro assays, all monoterpeneswere inhibitory to C. polonica. Limonene and bpinenewere the most potent inhibitors of fungal growth. The extent of inhibition varied between the three strainstested. These results showed a defense response of Norwayspruce to C. polonica, in which limonene may play acritical role in inhibiting the spread of the fungus. We alsoshowed that differences between strains of C. polonicamust be taken into account when assessing the role of thefungus in this bark beetlesymbiont system.
Keywords		glivice rast zaviranje fungi growth inhibition