Dynamics of the volatile defense of winter "dormant" balsam poplar (Populus balsamifera).
6-Hydroxycylohex-2-en-1-one (6-HCH) has been reported as a major chemical defense of the winter-dormant internodes of balsam poplar (Populus balsamifera) against feeding by herbivores such as the snowshoe hare (Lepus americanus). We report that the concentration of 6-HCH in the fall internodes is triggered by a single hard frost, and then undergoes an exponential decline through volatilization over the winter that results in barely detectable quantities by early spring. We conclude that the role of 6-HCH in the defense of mature balsam poplar is more complex than simply acting as a toxin. Rather, 6-HCH's role as a defensive agent must evolve over the course of the winter from being a co-toxin to a cue for a conditioned flavor aversion (CFA) to finally having no role by late spring.
Clausen
Thomas P
TP
Department of Chemistry & Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775-6160, USA. tpclausen@alaska.edu
Chen
Janice
J
Bryant
John P
JP
Provenza
Frederick D
FD
Villalba
Juan
J
D000818:Animals; D003512:Cyclohexanones / Q000737:chemistry / Q000633:toxicity*; D006027:Glycosides / Q000737:chemistry / Q000633:toxicity*; D034621:Hares; D032107:Populus / Q000502:physiology*; D012621:Seasons; D014835:Volatilization
D003512:Cyclohexanones; D006027:Glycosides
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