Figure 2.—

The absence of PIF1 in phyA, phyB, cry1, and cry2 mutant background enhances photomorphogenic responses under diurnal (12 hr light/12 hr dark) blue light conditions. Fluence-rate response curves of mean cotyledon angles (A, D, G, and J) and hypocotyl lengths (B, E, H, and K) of wt (Col-0), pif1, pif1phyA (A–C), pif1phyB (D–F), pif1cry1 (G–I), and pif1cry2 (J–L) grown for 4 days under either dark or diurnal (12 hr light/12 hr dark) blue light conditions are shown. Hypocotyl lengths were normalized by setting the dark values to 100. Data are presented as mean ± SEM (n ≥ 30, three replicates). (C, F, I, and L) Photographs of seedlings of different genotypes grown under diurnal (12 hr light/12 hr dark) blue light conditions (1.2 μmol m⁻² sec⁻¹) for 4 days are shown. White bar, 5 mm.