Repressor of jasmonate responses. Jasmonoyl-isoleucine (JA-Ile) specifically promotes COI1-TIFY10B/JAZ2 interaction. Activated by MYC2, MYC3 and MYC4 transcription factors (PubMed:19151223, PubMed:21335373). 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 COI1, MYC2, MYC3, MYC4, AFPH2/NINJA, TIFY10A/JAZ1, TIFY6B/JAZ3, TIFY11A/JAZ5, TIFY11B/JAZ6, TIFY5A/JAZ8, TIFY7/JAZ9, TIFY9/JAZ10, TIFY3A/JAZ11 and TIFY3B/JAZ12 (PubMed:18547396, PubMed:19151223, PubMed:19309455, PubMed:20360743, PubMed:21335373). Interacts with RHD6 and RSL1 (PubMed:31988260). (Microbial infection) Interacts with the pathogenic Pseudomonas syringae HopZ1a protein. Expressed in cotyledons, hypocotyls, roots, sepals, petal vascular tissue and stigmas of developing flowers. Expressed in stamen filaments after jasmonic acid treatment. (Microbial infection) Triggered to degradation by the pathogenic Pseudomonas syringae HopZ1a protein in a COI1-dependent manner, thereby activating host jasmonate signaling. Up-regulated by jasmonate, wounding and herbivory. The jas domain (204-229) is required for interaction with COI1 and Pseudomonas syringae HopZ1a. (Microbial infection) Acetylated by Pseudomonas syringae HopZ1a. Ubiquitinated. Targeted for degradation by the SCF(COI1) E3 ubiquitin ligase-proteasome pathway during jasmonate signaling. Belongs to the TIFY/JAZ family.