Creating ruffled flower petals in cyclamen persicum by expression of the chimeric cyclamen TCP repressor

Cyclamen persicum is among the most popular pot plants in the world. Creating new ruffled flower petals is an important breeding target in this plant. TCP transcription factors are involved in defining plant morphology in angiosperms. To modify flower shape in cyclamen, we isolated a TCP gene from cyclamen (CpTCP1), which is clustered in the same group as TCP3 (AtTCP3) and TCP4 (AtTCP4) in Arabidopsis and CINCINNATA (CIN) in Antirrhinum majus. A chimeric repressor gene construct for CpTCP1 driven by the cauliflower mosaic virus (CaMV) 35S promoter (35S:CpTCP1SRDX) was transformed into Arabidopsis to confirm whether CpTCP1 has a function similar to that of AtTCP3 in Arabidopsis. The phenotypic changes resembled those of the chimeric repressor derived from AtTCP3. The 35S:CpTCP1SRDX was introduced into cyclamen cv. Wink Pink. Finally, we produced and analyzed 106 independent transgenic plants. CpTCP1SRDX expression resulted in cyclamen with serrated wavy leaves and curled petals. Scanning electron microscopy showed that cells in petals and leaf margins of 35S:CpTCP1SRDX plants were smaller than those of controls, and these cells also appeared immature. These results suggest that cyclamen CpTCP1 possibly plays a role in regulating morphogenesis in floral and vegetative organs. We demonstrated that CpTCP1SRDX expression in cyclamen resulted in curly and ruffled flowers with a high ornamental value.