Plant biology

Spring Into Flower

Science Signaling  29 May 2012:
Vol. 5, Issue 226, pp. ec152
DOI: 10.1126/scisignal.2003256

In spring, plants respond to increasing day length and shifts in the spectrum of solar irradiance by releasing the flowering induction pathway, which includes expression of the gene encoding the protein FLOWERING LOCUS T (FT). Song et al. have now identified a trio of controls brought to bear on FT gene expression by the FKF1 (FLAVIN-BINDING, KELCH REPEAT, F-BOX 1) protein. FKF1 removes a repressor and also stabilizes the activating CONSTANS (CO) protein in the afternoons through a binding interaction enhanced by blue light—an increasing component of solar irradiation during spring. Then FKF1 itself helps to activate transcription of the CO gene. Thus, by removing the repressor and shoring up the activator, FKF1 sets flowering on its way.

Y. H. Song, R. W. Smith, B. J. To, A. J. Millar, T. Imaizumi, FKF1 conveys timing information for CONSTANS stabilization in photoperiodic flowering. Science 336, 1045–1049 (2012). [Abstract] [Full Text]