Diurnal cycle of sparteine production in Lupinus arcticus

Sparteine is a neurological toxin found in arctic lupine ( Lupinus arcticus S. Wats.) and is probably used as a defensive chemical to deter herbivory, particularly by snowshoe hares ( Lepus americanus Erxleben). Lupine leaves were collected in southwestern Yukon at 2 h intervals for 2 consecutive da...

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Bibliographic Details
Published in:Canadian Journal of Botany
Main Authors: Sharam, Gregory J., Turkington, Roy
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2005
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Online Access:http://dx.doi.org/10.1139/b05-104
http://www.nrcresearchpress.com/doi/full-xml/10.1139/b05-104
http://www.nrcresearchpress.com/doi/pdf/10.1139/b05-104
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Summary:Sparteine is a neurological toxin found in arctic lupine ( Lupinus arcticus S. Wats.) and is probably used as a defensive chemical to deter herbivory, particularly by snowshoe hares ( Lepus americanus Erxleben). Lupine leaves were collected in southwestern Yukon at 2 h intervals for 2 consecutive days at the peak of the growing season (24–25 June), and their sparteine was extracted and compared with a standard using gas chromatography. A significant daily cycle of sparteine in leaf material was observed, with maximum concentrations occurring during the night and minimum during the afternoon. This may be a temporally optimal response to higher levels of hare herbivory that occur at night.