Beyond the blue rose: Modification of floral architecture with plant-specific chimeric repressors

Abstract

There is a significant difference between cereal crops and floricultural crops in the concept of genetic modification. This is due to the difference in requirements for these agricultural products; wide variation of flower color, shape and fragrance for floricultural plants in contrast to productivity improvements or fine-tuning of physiological traits for crop plants. Bringing GM flowers to the market against their short product life involves the following factors: (1) a high-efficiency production and screening system of elite lines, (2) reliable methods to minimize biodiversity impact and evaluation of their efficacy, and (3) social receptivity based on intensive education and information sharing. We have developed an efficient system by merging the genetic information resources of the Arabidopsis genome and a transcription factor-based gene silencing system called CRES-T through the Flower CRES-T Project. In this project, we have demonstrated the applicability and general versatility of CRES-T in various plant species through experiments on eight different flower species with over 100 transcription factors. In addition to providing phenotypic information via the original database, we are attempting to improve public knowledge, for example, through the production of resin-embedded specimens of GM-flowers and reviving lost garden varieties of morning glory and using them in educational programs, to gain public acceptance of GM plants. Multi-petal cyclamens with complete sterility, which have been produced by suppressing a pair of floral-organ identity genes, will be released in the near future as the third GM commodity following Suntory's blue carnations and rose. This cyclamen represents the best example of a GM product with a low diversity impact ever produced.