Signal signature of Arabidopsis induced upon pathogen and insect attack

Three plant signaling molecules play a dominant role in the regulation of defences in a number of plant-attacker model systems: salicylic acid (SA), jasmonic acid (JA) and ethylene (ET). In this study, the roles of these compounds were determined in the induced defense responses of Arabidopsis thaliana upon attack by a set of microbial pathogens and herbivorous insects. The production of SA, JA and ET was activated in different combinations depending on the attacker encountered resulting in a specific signal signature. Analysis of the expression of SA-,JA-,and ET responsive marker genes showed that the signal signature nicely correlates with the expression of the marker genes in each plant-attacker interaction. We hypothesize that the specific signal signature is involved in the activation of an optimal mix of defenses to counteract the intruder.