Repressor of jasmonate responses (PubMed:19151223). Interacts with and suppresses RHD6 and RSL1 transcription factor activities to negatively regulate jasmonate-stimulated root hair development (PubMed:31988260). Homo- and heterodimer. Interacts with MYC2, AFPH2/NINJA, TIFY10A/JAZ1, TIFY6B/JAZ3, TIFY5A/JAZ8, TIFY9/JAZ10 and TIFY3A/JAZ11 (PubMed:19151223, PubMed:19309455, PubMed:20360743). Interacts with RHD6 and RSL1 (PubMed:31988260). A number of isoforms are produced. According to EST sequences. Up-regulated by wounding and herbivory. The jas domain (259-284) is required for interaction with COI1. Ubiquitinated. Targeted for degradation by the SCF(COI1) E3 ubiquitin ligase-proteasome pathway during jasmonate signaling. Belongs to the TIFY/JAZ family.