Perception of an insect pheromone primes plant defense responses

Anjel Helms, Penn State

March 1, 2012 @ 12:20 pm to 01:10 pm

111 Tyson Building

Olfactory cues mediate a wide array of ecological interactions, including those among plants and insects. Some of the best-documented examples of these interactions are pheromonal communication among conspecific insects and the use of plant odors as foraging cues by insect pollinators, herbivores and predators. Recent work has shown that plants themselves can also perceive and respond to olfactory cues. Some parasitic plants grow toward host plant odors and other plants have been shown to prime their anti-herbivore defenses following exposure to volatiles emitted by insect-damaged plant tissues. Here we demonstrate for the first time that plants can perceive and respond to olfactory cues emitted directly by insect herbivores. Initial data from my research suggest that tall goldenrod (Solidago altissima) primes its anti-herbivore defenses following exposure to the sex pheromone its specialist herbivore Eurosta solidaginis. S. altissima plants experimentally exposed to E. solidaginis pheromone experienced significantly less feeding damage than control plants or plants exposed to the pheromone of an unassociated insect herbivore. Moreover, plants exposed to E. solidaginis pheromone exhibited a stronger induction of the key defense signaling hormone jasmonic acid in response to insect feeding. These findings indicate that the pheromones of insect herbivores may provide another cue predicting impending herbivory and that some plants can eavesdrop on this cue to prime their anti-herbivore defenses._

Contact

Jason Hill
ecologyservice@psu.edu