Figure 5.

Phytochrome-induced enhancement of phot1-dependent phototropism in Arabidopsis.

(A) Three-d-old etiolated seedlings mock-irradiated for 8 h.

(B) Three-d-old etiolated seedlings mock-irradiated for 4 h, then exposed to 4 h of unilateral blue light (λ_max = 436 nm, 30 nm half-band; at a fluence rate of 0.1 µmol m^-2 s^-1) from the left.

(C) Three-d-old etiolated seedlings exposed to 4 h of red light (λ_max = 660 nm, 30 nm half-band; at a fluence rate of 0.3 µmol m^-2 s^-1) from above, then 4 h of unilateral blue light (λ_max = 436 nm, 30 nm half-band; at a fluence rate of 0.1 µmol m^-2 s^-1) from the left.