Fig. 1: FHY3 and FAR1 play a role in regulating branching in response to light quality change.

a Comparison of the rosette branch number of fhy3-11, far1-4, fhy3 far1, FHY3 overexpressor, and WT plants grown under normal conditions (WL) or stimulated shade conditions (EOD-FR). Eight-day-old seedlings were moved into the soil and grown under WL with or without EOD-FR treatment for 4 weeks before phenotyping. Arrow indicates the short rosette branches. b Quantification of the number of rosette branches of fhy3-11, far1-4, fhy3 far1, FHY3 overexpressor, and WT plants grown under WL or EOD-FR conditions. Values shown are mean ± SD (n = 12). Letters indicate significant differences by two-sided LSD test (p < 0.05). c The transcript levels of FHY3 and FAR1 are downregulated by EOD-FR treatment. Seven-day-old seedlings grown under WL conditions were treated with or without EOD-FR for 30 min and then harvested for RNA extraction. Values shown are mean ± SD (n = 3). **p < 0.01 by two-sided Student t test. d Western blotting assay showing that both FHY3 protein level rapidly declined in seedlings treated with EOD-FR. Anti-FLAG antibodies were used to detected FHY3 protein and actin was adopted as a loading control. This assay was repeated for three times and similar results were obtained. e Fluorescence microscopic analysis of FHY3-YFP protein levels. This assay was repeated for three times and similar results were obtained. The relative fluorescence intensity was quantified by measuring the fluorescence pixel intensity using software Image J. Values shown are mean ± SD (n = 6). **p < 0.01 by two-sided Student t test. Scale bar = 50 μm.