Conifer chemical defenses influence meal properties of the pine weevil Hylobius abietis
(English)Manuscript (preprint) (Other academic)
Chemical defenses of conifers can be experimentally activated to respond more efficiently to feeding damage by insects. One chemical elicitor that triggers plant defenses, and thereby protects conifers, is methyl jasmonate (MeJA). However, there is little known about the associations between MeJA-induced conifer defenses, and the meal properties of phytophagous insects. To address this knowledge gap, we have analyzed relations between volatile contents of Scots pine (Pinus sylvestris L.) tissues, and meal properties of the pine weevil (Hylobius abietis (L.)). Phloem and needles (both weevil target tissues) from MeJA-treated and control seedlings were extracted by n-hexane and analyzed by two-dimensional gas chromatography-mass spectrometry (2D GC-MS). Feeding of pine weevils on seedlings from the same batches were video-recorded to determine meal properties. Multivariate statistical analyses showed that phloem and needle contents of MeJA-treated seedlings had different volatile compositions from the control seedlings. Levels of (+)-α-pinene were high, and levels of the antifeedant 2-phenylethanol were low, in phloem of control seedlings with feeding damage. Accordingly, pine weevils fed more slowly and had shorter meals on MeJA-treated seedlings. In addition, the chemical compositions of phloem and needles – and accordingly weevil meal durations on them – were more similar in MeJA-treated seedlings than in controls. The results illustrate that detailed knowledge of insect responses can help efforts to identify and elucidate specific roles of resistance agents in complex chemical profiles.
Pinaceae; Pinus sylvestris; Hylobius abietis; Short-term feeding; Induced defense; Methyl jasmonate; Phloem; Needles; Terpenes; Aromatics
Organic Chemistry Analytical Chemistry Other Chemistry Topics Ecology
Research subject Chemistry
IdentifiersURN: urn:nbn:se:kth:diva-183267OAI: oai:DiVA.org:kth-183267DiVA: diva2:908933
FunderSwedish Foundation for Strategic Research , Parasite Resistant Trees
First and second author contributed equally to this work.
QS 20162016-03-032016-03-032016-03-04Bibliographically approved