Figure 7.

Pre-irradiation does not enhance phototropic responsiveness in ML1::PHOT1-GFP transgenic lines. Three-day-old etiolated seedlings expressing ML1::PHOT1-GFP (A) or PHOT1::PHOT1-GFP (B) were maintained in darkness (Control), irradiated with 20 μmol m⁻² s⁻¹ of over-head red light for 15 min (Red) or irradiated with 20 μmol m⁻² s⁻¹ of over-head blue light for 15 min (Blue) before being placed into 0.5 μmol m⁻² s⁻¹ of unilateral blue light for 3 h. Hypocotyl curvatures were measured every 10 min and each value is the mean ± S.E. of 16–21 seedlings. Asterisks indicate significant differences between red or blue light treated and control seedlings (P < 0.001, Student's t-test).