Fig. 1.

PHY3 can mediate both RL- and BL-induced phototropic responses of phot1 phot2 transgenic Arabidopsis seedlings. (A) Phototropic response of Arabidopsis hypocotyls. Wild type, phot1–5 phot2–1, and two independent phot1–5 phot2–1 transformants expressing PHY3 (PHY3–1, PHY3–2) were grown in the dark for 3 days and irradiated by either unilateral BL (10 μmol·m⁻²·s⁻¹) or unilateral RL (1.0 μmol·m⁻²·s⁻¹) for 16 h before imaging. Arrows indicate the direction of lateral light irradiation. (B) Fluence rate response of hypocotyl phototropism. Phototropic responses were induced as in A. Each bar indicates a mean of 15 measurements with standard deviations.