Abstract
To create novel floral traits in horticultural flowers efficiently, we have introduced many kinds of Arabidopsis chimeric repressors with a transcriptional repression domain (SRDX) driven by CaMV 35S promoter into torenia. While various flowers with characteristic traits have been obtained so far, some of them were accompanied by unfavorable effects such as phenotypic changes in leaves and defects in opening flower buds. We therefore utilized floral organ specific promoters instead of CaMV 35S promoter not only to avoid these problems but also to create novel floral phenotypes. In this study, we produced novel floral traits with the chimeric repressors of Arabidopsis MYB24 and TCP3 using floral organ specific promoters in torenia. While a 35S:MYB24-SRDX torenia formed unopened flower buds and exhibited phenotypic change in leaves, expression of MYB24-SRDX driven by floral organ specific promoter leaded to blooming and induced distinctive petal phenotype without phenotypic change in leaves. Furthermore, the expression of TCP3-SRDX driven by five types of floral organ specific promoters enabled to create characteristic floral traits in each promoter.
