Transcription factor involved in tryptophan gene activation and in indole-3-acetic acid (IAA) and indolic glucosinolates (IG) biosynthesis. Acts as a direct transcriptional activator of both Trp synthesis genes and Trp secondary metabolism genes. Can form complexes with MYC2, MYC3 or MYC4. Expressed in trichomes. Up-regulated by herbivory. No visible phenotype. Reduced indolic glucosinolate levels in adult leaves and loss of responses to brassinosteroids.