Regulation of Flowering Time by Histone Acetylation inArabidopsis

Abstract
TheArabidopsisautonomous floral-promotion pathway promotes flowering independently of the photoperiod and vernalization pathways by repressingFLOWERING LOCUS C(FLC), a MADS-boxtranscription factor that blocks the transition from vegetative to reproductive development. Here, we report thatFLOWERING LOCUS D(FLD), one of sixgenes in the autonomous pathway, encodes a plant homolog of a protein found in histone deacetylase complexes in mammals. Lesions inFLDresult in hyperacetylation of histones inFLCchromatin, up-regulation ofFLCexpression, and extremely delayed flowering. Thus, the autonomous pathway regulates flowering in part by histone deacetylation. However, not all autonomous-pathway mutants exhibitFLChyperacetylation, indicating that multiple means exist by which this pathway repressesFLCexpression.