The nature of floral signals in Arabidopsis. I. Photosynthesis and a far-red photoresponse independently regulate flowering by increasing expression of FLOWERING LOCUS T (FT).

ABSTRACT: Arabidopsis flowers in long day (LD) in response to signals transported from the photoinduced leaf to the shoot apex. These LD signals may include protein of the gene FLOWERING LOCUS T (FT) while in short day (SD) with its slower flowering, signalling may involve sucrose and gibberellin. Here, it is shown that after 5 weeks growth in SD, a single LD up-regulated leaf blade expression of FT and CONSTANS (CO) within 4-8 h, and flowers were visible within 2-3 weeks. Plants kept in SDs were still vegetative 7 weeks later. This LD response was blocked in ft-1 and a co mutant. Exposure to different LD light intensities and spectral qualities showed that two LD photoresponses are important for up-regulation of FT and for flowering. Phytochrome is effective at a low intensity from far-red (FR)-ric

SUBMITTER: King RW 

PROVIDER: S-EPMC2576645 | biostudies-literature | 2008

REPOSITORIES: biostudies-literature