The Silence of the Flowering Genes

Science's STKE  09 Oct 2007:
Vol. 2007, Issue 407, pp. tw367
DOI: 10.1126/stke.4072007tw367

Transcription of genes is controlled by specific factors at each promoter and by a general state of activation or silencing in the surrounding chromatin. In the course of studying chromatin silencing in the plant Arabidopsis, Bäurle et al. noticed a defect in flowering. It seems that some of the genes already known to control flowering time, including FCA and FPA, also function to modify chromatin involved in other processes outside of flowering regulation. Haploid female gametophytic development and embryonic development seem to be particularly susceptible to failure of the chromatin-modification functions of FCA and FPA. Hence, FCA and FPA proteins are localized in the nucleus and are required for efficient silencing of a number of loci by mechanisms that seem to vary with different loci.

I. Bäurle, L. Smith, D. C. Baulcombe, C. Dean, Widespread role for the flowering-time regulators FCA and FPA in RNA-mediated chromatin silencing. Science 318, 109-112 (2007). [Abstract] [Full Text]