FHY1 Mediates phyA Nuclear Import Figure 3. A constitutively localized phyA is functional but does not trigger constitutive photomorphogenesis. (A) FR-HIR for inhibition of hypocotyl elongation. Col, phyA-211 and phyA-211 seedlings expressing phyA-NLS, phyA-NLS-GFP or phyA-GFP (two independent lines each) were grown in the dark (D) or in FR (0.3, 3 or 15 mmol m22 s21). After 5 days the hypocotyl length was measured. The mean value and the SD are indicated with n.15. (B) FR-HIR for anthocyanin accumulation. Col, phyA-211 and cop1-4 as well as the transgenic lines described in (A) were grown in the dark or in FR (5 mmol m22 s21). After 4 days the anthocyanin content was measured. The mean value (A530–A647/seedling) of three replicates and the SD are indicated. (C) VLFR for inhibition of hypocotyl elongation. Col, phyA-211 as well as the lines described in (A) were grown for one day in the dark and then exposed for 3 days to either continuous FR (20 mmol m22 s21) or 3 min FR pulses (20 mmol m22 s21) with different dark intervals (27, 57 and 127 min). At the end of the FR treatment the hypocotyl length was measured. Error bars indicate the SEM (n = 11). doi:10.1371/journal.pgen.1000143.g003 PLoS Genetics | www.plosgenetics.org 5 August 2008 | Volume 4 | Issue 8 | e1000143