PARENT SESSION
Oral Session #72: Herbivory: Herbivore Response to Plants.
Presiding: C. Mitchell
Wednesday, August 7. 1:00 PM to 4:45 PM. Mesquite Room, Radisson.
The role of the jasmonate pathway in plant resistance to pathogens.
Thaler, Jennifer*,1, Higging, Verna1, 1 University of Toronto, Toronto, ON, Canada
ABSTRACT- Plants integrate their defensive responses when attacked by multiple organisms at the same time. Two major defense pathways in plants, the jasmonate and salicylate pathways, have been thought to confer resistance to insects and pathogens, respectively. These pathways are known to be antagonistic to each other. This has set up a potential conflict for plants in defending themselves simultaneously against insects and pathogen attackers. It has also been hypothesized that the jasmonate response protects plants against necrotrophic pathogens but not biotrophic pathogens. This is because the salicylate response is associated with cell death, and not as effective against necrotrophic pathogens. Therefore, the jasmonate response is an alternative form of defense against necrotrophic pathogens. We tested this hypothesis using wild-type and jasmonate-deficient tomato plants that were challenged by eight necrotrophic and biotrophic pathogens. We found that jasmonate-deficient plants had higher levels of disease than wild-type plants. When the jasmonate-deficient plants were rescued by exogenous jasmonate treatment, disease resistance was restored. This conclusively demonstrates the role of the jasmonate response in resistance to both necrotrophic and biotrophic pathogens and forces us reevaluate the adaptive nature of antagonistic interactions between the jasmonate and salicylate defense responses in plants.
KEY WORDS: jasmonate, plant pathogen, disease