Chemical signals in plants: Jasmonates and the role of insect-derived elicitors in responses to herbivores

In any environment where plants grow, one can be quickly awestruck at the complex relationships that occur between plants and insects. Striking variation in the types of responses, on both sides of the interaction, is easily observed at the whole-organism level and these are multiplied many times over when events are considered at the cellular, biochemical, and molecular levels. A multitude of potential responses can occur in a plant following injury by a phytophagous insect. Complex sets of signals modulate a suite of responses, either within a given plant in response to different herbivores or in different plant species in response to similar herbivores (Figure 11.1). Understanding the central themes of plant defense against insects, as well as those responses unique to a particular insect or plant, is key to obtaining an overall picture of plant defenses against herbivores.