Arabidopsis ECAP is a New Adaptor Protein that Connects JAZ Repressors with TPR2 Co-repressor to Suppress Jasmonate-Responsive Anthocyanin Accumulation

Suppression mechanism employed by transcriptional repressors is commonly existed in diverse phytohormone signaling. In Arabidopsis thaliana, JASMONATE-ZIM DOMAIN (JAZ) proteins act as transcriptional repressors and involve in different aspects of the JA signaling network, through recruiting general co-repressors TOPLESS (TPL) and TPL-related proteins (TPRs). To accomplish overlapping but also finely separated functions of JAZ proteins, specificadaptor proteins are employed in JA signaling. Novel Interactor of JAZ (NINJA) is an adaptor protein mediates gene repression in JA-dependent root growth inhibition and pathogen defense. However, the adaptor protein(s) modulate other JA responsive biological processes is still a mystery. In this study, we demonstrated that a previously uncharacterized protein, ECAP(EAR-Containing Adaptor Protein) that connects JAZ6/8 and TPR to repress JA-mediated anthocyanin accumulation at low JA level. We also found ECAP-mediated transcriptional repression might play a general role in multiple aspects of plant development and responses to environments. Overall design: 18 Samples are analyzed, wild type and mutant seedlings were treated by 50 µM JA for 0, 1 and 3 hours. Three repeats for wild type and mutant at each time point. Wild type was set as control.