The JAZ proteins link jasmonate perception with transcriptional changes.

The oxylipin jasmonic acid (JA) and its metabolites, collectively known as jasmonates, are important plant signaling molecules that mediate biotic and abiotic stress responses as well as aspects of growth and development. Although it is well known that JA regulates transcription, the mechanism of this regulation has been largely unknown. Recently, this situation changed dramatically with the discovery of a novel family of transcriptional regulators called jasmonate ZIM-domain (JAZ) proteins. Three groups independently identified members of this family in Arabidopsis and showed that they function as repressors of JA-regulated transcription. Furthermore, genetic, molecular, and biochemical studies indicate that the JAZ proteins are degraded by the ubiquitin protein ligase SCFCOI1 in response to JA. In addition, one group showed that JAZ proteins interact with the positive regulator of JA signaling, MYC2. These data support an important new model of jasmonate signaling and response. In this essay, we summarize this recent work and discuss some remaining questions concerning JA signal transduction.