Efficient Screening of Torenia fournieri with Novel Floral Traits by Bulk Introduction of Chimeric Repressor for Arabidopsis Transcription Factors

Abstract

Molecular breeding enables us to produce novel floral traits of horticultural plants which could not be obtained by traditional breeding. However, it is difficult to find out useful genes for valuable floral traits without regenerating transgenic plants. To obtain new floral traits efficiently, we simultaneously introduced 42 chimeric repressors for Arabidopsis transcription factors which highly expressed in flowers into torenia (Torenia fournieri) and screened phenotypically-altered 193 lines of 348 transgenic plants. We found that 82.4% of them had single transgene, and 39 of 42 constructs were introduced independently. One third of transgenic torenias with single transgene induced recognizable phenotypes in floral color and/or shape as expected. These results indicate that bulk introduction of Arabidopsis genes can efficiently produce novel horticultural plants with valuable traits. Now we are transforming another bulk set of 50 genes selected with different approach to explore further variation of floral traits.