Figure 2.

Expression and Localization Analysis of EPR1.

(A) RNA gel blot analysis confirming the phyA and phyB regulation of EPR1 expression in wild-type and phy mutant seedlings. Total RNA (10 μg) from etiolated wild-type Landsberg erecta seedlings (WT) and phyA mutant seedlings that were harvested after 60 min of dark incubation and 10 mmol m⁻² FR light irradiation (FR60). Seedlings kept in total darkness (D) were used as a control.

(B) Total RNA (10 μg) from wild-type Landsberg erecta seedlings, phyA mutant seedlings, and phyA phyB double mutant seedlings that were exposed to R light (R; 1 mmol m⁻²), R light followed by FR light (R/FR; 1 mmol m⁻² and 10 mmol m⁻²), or FR light only (FR; 10 mmol m⁻²) and then kept in darkness for 60 min. 18S rRNA was included for normalization purposes.

(C) Six-day-old etiolated wild-type Landsberg erecta seedlings were treated with 300 μM cycloheximide (CHX+) or without cycloheximide (CHX−) for 2 h before R light treatment (1 mmol m⁻²). Total RNA (25 ng) from 0, 30, 60, 120, and 240 min of dark incubation after R light treatment was analyzed by semiquantitative reverse transcriptase–mediated PCR. ACT8 and rbcS were used as controls.

(D) Subcellular localization of an EPR1:GFP fusion protein in onion epidermal cells. Epifluorescence analysis showing GFP fluorescence in the nucleus was confirmed by 4′,6-diamidino-2-phenylindole (DAPI) staining. Bars = 100 μm.