Figure 2.

Time-Dependent Second Positive Phototropism in the rpt2-2 Mutant.

Dark-grown seedlings were pretreated with or without overhead red light (RL). After 2 h, the hypocotyls were stimulated with unilateral blue light (BL). The hypocotyl curvatures were determined 3 h after the onset of blue light.

(A) Experimental scheme for time-dependent second positive phototropism.

(B) to (E) Time-dependent second positive phototropism. The dark-grown seedlings were pretreated with (red symbols) or without (black symbols) overhead red light, and they were irradiated with unilateral blue light at 0.17 μmol m^–2 s^–1 ([B] and [C]) and 0.0017 μmol m^–2 s^–1 ([D] and [E]) for 1, 3, 9, 27, 81, and 180 min. The data shown are means ± se from 11 to 16 seedlings.