Chapter 10 Transcriptional Regulation of Plant Defense Responses

Plants possess constitutive as well as inducible defense systems to oppose attack by pathogens and herbivores. Signal-transduction pathways mediated by the plant hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) are involved in regulating appropriate defense responses. Extensive cross-talk between these different signal-transduction pathways allows the plant to fine-tune its defenses against different types of pathogens and insect attackers. This review presents brief overviews of the separate JA, ET, and SA signal-transduction pathways, followed by a description of the main classes of transcription factors involved in defense gene activation. The last part is devoted to recent work highlighting the regulation of plant defense responses by transcriptional reprogramming at the chromosomal level.