Figure 2.

Resistance signaling is elicited differently from simple wounding when herbivore-specific elicitors (FACs) are introduced into wounds during caterpillar feeding. Signaling depends on primary metabolites. Herbivory induces a large reorganization of primary metabolism, including altered photosynthesis and altered sink/source relations. These changes are coordinated by a signaling network that is only partially understood. The expression of defense and tolerance traits requires changes both in primary and secondary metabolism.