title: Alkaloidal responses to damage inNicotiana native to North America.
abstract: We performed field tests of alkaloid induction inNicotiana attenuata plants growing in southwestern Utah with mimicry of the two major types of damage inflicted by invertebrate and vertebrate herbivores: leaf damage and stalk removal, respectively. In undamaged plants, seasonal increases in leaf nicotine content occurred at a rate of 0.046% leaf dry mass/day. Leaf damage doubled the accumulation rate to 0.086-0.138% leaf dry mass/day, while stalk removal resulted in a quadrupling of the accumulation rate to 0.206% leaf dry mass/day. These damage-induced increases in nicotine accumulation are significantly larger than between-plant and phenological variations. Leaf damage to the nornicotine-(N. repanda andN. trigonophylla) and anabasine-accumulating (N. glauca)Nicotiana species native to North America resulted in 1.5- to 5-fold increases in their principal leaf alkaloid pools. We conclude that alkaloid induction is not limited to nicotine-accumulatingNicotiana species and that herbivores feeding on previously damaged plants are likely to encounter tissues with alkaloid titers significantly higher than those of undamaged plants.
authors.affiliation: Department of Biological Sciences, SUNY at Buffalo, 14260-1300, Buffalo, New York.
authors.forename: I T
authors.initials: IT
authors.lastname: Baldwin
authors.forename: T E
authors.initials: TE
authors.lastname: Ohnmeiss