PARENT SESSION
Contributed Oral Session 65: Herbivory: Physiological Responses
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 520 A, Level 5, Palais des congrès de Montréal
Airborne plant-plant signaling between big sage, Artemisia tridentata, and wild tobacco, Nicotiana attenuata in nature.
Kessler, Andre*,1, Halitschke, Rayko1, Baldwin, Ian2, 1 Cornell University, Ithaca, NY, USA2 Max Planck Institute for Chemical Ecology, Jena, Germany
ABSTRACT- Plants release volatile organic compounds (VOCs) in response to wounding and herbivore attack. Some of these compounds trigger responses in neighboring unattacked plants under ecologically questionable conditions in the laboratory. Whether plants eavesdrop on the volatiles emissions of their neighbors in nature is not known. The best documented field study of between-species signaling via above-ground VOCs involves increases in fitness parameters of native tobacco transplanted adjacent to clipped sagebrush plants. Clipped sagebrush elicits many biologically active VOCs, including methyl jasmonate (MeJA), methacrolein and a series of terpenoid and greenleaf VOCs, of which MeJA, while active under laboratory conditions, is not sufficient in itself to elicit induced resistance in the field. With microarrays enriched in N.attenuata herbivore-regulated genes, we found transcriptional responses in tobacco plants growing adjacent to clipped sage foliage but failed to detect the direct elicitation of defensive chemicals or proteins. However, we observed an accelerated production of defensively active trypsin proteinase inhibitors when Manduca sexta hornworms fed on plants previously exposed to clipped sage compared to unexposed plants. This priming of a defense response results in lower total herbivore damage on plants exposed to clipped sage and in a higher mortality rate of neonate Manduca caterpillars.
Key words: plant-plant communication, induced plant responses, herbivory, plant defenses