Figure 1

Adding injury to insult. The signaling machinery for pathogen and pest recognition may be intimately associated with core signaling elements that respond to physical stress.Organisms that attack plants inevitably modify host gene expression through being recognized by molecular determinants (elicitors) and through physical damage to cells and tissues (a). Attackers which succeed in modifying their elicitors to either partially (b) or completely (c) escape detection still activate host gene expression through interaction with physical stress pathways. One strategy to ensure successful attack, which might be used by some insects, would minimize both insult and injury.