Fig. 7

Working model for hypocotyl elongation control by BAF60 chromatin remodeling. BAF60 is more abundant under light conditions and represses expression of hypocotyl elongation regulatory genes, IAA19, ST2a, XTR7, SDR, HFR1, and BEE1, upon recruitment onto G-box motifs by modulating DNA accessibility. In darkness and at nighttime the abundance of BAF60 decreases, possibly allowing PIF proteins to bind the same regulatory loci and promote expression of the target genes. However, remaining BAF60 protein competes with PIF4 for binding on their common targets, thereby fine-tuning the expression level of genes involved in cell size control