Figure 4.

HDA15 and HY5 act interdependently in repressing hypocotyl elongation. A, Hypocotyl length of 4-d–old Col-0, hy5-215, 35S:HDA15-GFP, and 35S:HDA15-GFP hy5 seedlings grown under red light (13.12 μmol m⁻² s⁻¹). Two independent lines of 35S:HDA15-GFP and 35S:HDA15-GFP hy5 were analyzed. Asterisks indicate the significant difference (P < 0.05, Student’s t test; n > 20). B, Hypocotyl length of 4-d–old Col-0, hy5-215, 35S:HDA15-GFP, and 35S:HDA15-GFP hy5 seedlings grown under far-red light (3.82 μmol m⁻² s⁻¹). Two independent lines of 35S:HDA15-GFP and 35S:HDA15-GFP hy5 were analyzed. Asterisks indicate the significant difference (P < 0.05, Student’s t test; n > 20). C, Hypocotyl length of 4-d–old Col-0, hda15-1, 35S:HY5-GFP-1, and 35S:HY5-GFP hda15-1 seedlings grown under red light (13.12 μmol m⁻² s⁻¹). Asterisks indicate the significant difference (P < 0.05, Student’s t test; n > 20). D, Hypocotyl length of 4-d–old Col-0, hda15-1, 35S:HY5-GFP-1, and 35S:HY5-GFP hda15-1 seedlings grown under far-red light (3.82 μmol m⁻² s⁻¹). Asterisks indicate the significant difference (P < 0.05, Student’s t test; n > 20). E, Hypocotyl length of 4-d–old Col-0, hda15-1, hy5-215, and hda15 hy5 double mutants grown under red light (13.12 μmol m⁻² s⁻¹). Asterisks indicate the hypocotyl length of these mutants is significantly different from that of Col-0 (P < 0.05, Student’s t test; n > 20). F, Hypocotyl length of 4-d–old Col-0, hda15-1, hy5-215, and hda15 hy5 double mutants grown under far-red light (3.82 μmol m⁻² s⁻¹). Asterisks indicate the hypocotyl length of these mutants is significantly different from that of Col-0 (P < 0.05, Student’s t test; n > 20).