Abstract
Epidermal cell has diverse functions and differentiates into various specialized cells including trichome and stomatal guard cells. Cuticle layer is formed on the aerial surface of mature epidermal cells. Although WAX INDUCER/SHINE (WIN/SHN) transcription factors have been shown to activate genes for cutin and epidermal wax biosynthesis, other regulators are hardly known. Therefore, we screened transcription factors that induce organ adhesion when CRES-T is applied and found that EPIDERMAL DEFECT1 (EPD1) fused with repression domain (SRDX) induced adhesion of surface of buds and leaves and reduction of the epicuticular wax crystals. Expression analyses revealed that EPD1 regulates the expression of WIN/SHN genes. We further found that epidermal cells of EPD1SRDX plants showed aberrant morphology and the expression of ATML1, a marker gene for epidermal cell, was down-regulated. In addition, the transgenic torenia expressing EPD1SRDX lacked some epidermal cells in petal. Our results suggested that EPD1 regulates not only wax and cutin biosynthesis but also establishment of epidermal cell.
