Abstract
CRES-T(Chimeric REpressor gene-Silencing Technology) system is a powerful tool for genetic engineering of floriculturel plants, and transcription factor changes into transcriptional repressor by connecting the transcription repression domain, SRDX. The chimeric repressor dominantly suppresses the target genes. However, in some cases, severe growth defects and decreases in ability of fertilization were observed. In this study, we developed the new technology to control the expression of the transgene. The transcription system of the GAL4DB transcription factor of yeast was used, and the vectors which GAL4SRDX expressed by inducible promoters (Heat-shock pro or Alc pro) were constructed, and GAL4SRDX represses the overexpression of transgene, under the control of the 35S promoter:GAL4 UAS. Transgenic Pharbitis plants overexpressing the DPSRDX, which is a homolog of AG in Pharbitis, formed a double flower bud, but its growth stopped during the in vitro redifferentiation. Whereas, Heat-shock or EtOH treatment induced the GAL4SRDX expression, thus double flower Pharbitis was generated. Furthermore, we succeeded to induce non-transformant(NT) like flower in the double flower Pharbitis.
