Figure 9.

Effects of NPA and 1-NOA on hypocotyl phototropic curvature and changes in [Ca²⁺]_cyt induced by BL in phot1, phot2, and phot1phot2 mutants. A, Seedlings were grown vertically on agar plates without (Control) and with 1 μm NPA or 10 μm 1-NOA and then exposed to BL illumination at 100 μmol m⁻² s⁻¹ for 12 h. Phototropic curvature was measured as shown in Figure 6B. The values are averages of three independent experiments (40–60 measurements each) with sd. B, Mean changes in cytosolic Ca²⁺ in response to 100 μmol m⁻² s⁻¹ BL for 15 s in etiolated seedlings. Before measuring the [Ca²⁺]_cyt, 1 μm NPA or 10 μm 1-NOA was added to the solution in the dark for 1 h. The values are averages of three independent experiments (11–19 measurements each) with sd. WT, Wild type. C, Effects of exogenous auxin on the changes in [Ca²⁺]_cyt. The values are averages of three independent experiments (10–15 measurements each) with sd. *P < 0.05, **P < 0.01.