Transcription activator involved in the transcriptional regulation of terpene biosynthesis in glandular trichomes (PubMed:24884371, PubMed:24142382). Binds to the promoter of the linalool synthase TPS5 and promotes TPS5 gene transactivation (PubMed:24884371, PubMed:24142382). Acts synergistically with MYC1 in the transactivation of TPS5 (PubMed:24884371). Forms homodimers and heterodimers with LRP1. Belongs to the SHI protein family.