Loss of phyF when combined with loss of phyB1 affects the reduction of hypocotyl growth during photomorphogenesis in Rc. Seeds were germinated in the dark for 3–4 days. Synchronously germinated seedlings were transferred to R and allowed to grow for 4 days in Rc (15 µE), before being photographed, and analyzed using ImageJ as described in the Methods. Data were statistically analyzed using 2-way ANOVA, which showed a significant effect of interaction between genotype and light condition on hypocotyl length (P < 0.001). The data were subsequently analyzed with a Tukey post hoc test. Means not connected by the same letter are statistically significantly different from each other at P < 0.05. An asterisk indicates statistical significance at P < 0.05 from the dark treatment. For each genotype, four biological replicates were performed with similar results and data were pooled for this figure. Sample sizes were as follows (dark/red): A (phyA) = 112 (55/57), AB2F (phyAB2F) = 40 (16/24), AF (phyAF) = 122 (62/60), B1 (phyB1) = 91 (41/50), B1B2 (phyB1B2) = 99 (50/49), B1B2F (phyB1B2F) = 102 (55/47), B1F (phyB1F) = 96 (48/48), B2 (phyB2) = 107 (53/54), B2F (phyB2F) = 40 (17/24), F11 (phyF-11) = 113 (59/54), F413 (phyF-413) = 96 (46/50), F44 (phyF-44) = 119 (57/62), Wild-type cv. Moneymaker (WT) = 295 (141/154). Error bars reflect SE. The genotype phyB1B2F contained a mutation in a presumably unrelated second gene. A: shows data as absolute values; B: shows data as values relative to the dark response. Both A and B use the same data set. Shaded boxes are used to highlight the only three genotypes not responding to Rc. Rc = continuous red light; D = dark, R = red light; n.s. = not significant.