RNA sequencing on Solanum lycopersicum trichomes identifies transcription factors that activate terpene synthase promoters
Terpene biosynthesis in tomato glandular trichomes has been well studied, with most if not all terpene synthases (TPSs) being identified. However, transcription factors (TFs) that regulate TPSs have not yet been discovered from tomato. In order to unravel the transcriptional regulation of the Solanum lycopersicum linalool synthase (SlMTS1, recently renamed SlTPS5) gene in glandular trichomes, we functionally dissected its promoter. A 207 bp fragment containing the minimal promoter and the 5′UTR appeared to be sufficient for trichome-specific expression in transgenic plants. Yeast-one-hybrid screens with this fragment identified a glandular trichome-specific transcription factor, designated Expression of Terpenoids 1 (SlEOT1). SlEOT1 is a member of a conserved family of TFs that includes the Arabidopsis Stylish 1 (AtSTY1) and Short Internode (AtSHI) genes. The EOT1 protein localized to the nucleus and specifically transactivated the SlTPS5 promoter in Nicotiana benthamiana leaves.