Abstract
Plants can measure the day-length to set seeds at their appropriate seasons. We are currently understanding better and better how the long-day plant, Arabidopsis, recognizes photoperiods. The molecular mechanism in which two key transcriptional factors, CO and CDF1, are independently regulated through light signal- dependent protein degradation and CDF1 regulates CO transcription, exceeds our expectation in term of the complexity. In the short-day plant, rice, an evolutionally conserved cascade of transcriptional regulation such as OsGI-Hd1-Hd3a, which is corresponding GI-CO-FT in Arabidopsis , controls flowering-time. A reverse of the key transcriptional regulation confers the short-day response although protein stability regulation of Hd1 could be different from CO regulation observed in Arabidopsis. In addition, there could more complex network such as the Ehd1 pathway in photoperiodic flowering of rice. In this symposium, I would like to talk the molecular diversity of photoperiodic flowering in plants.
