Immunoblot analyses of PHOT1, NPH3, and RPT2 proteins. (a) Time-course analysis of changes in PHOT1, NPH3, and RPT2 proteins. Two-day-old etiolated seedlings of wild-type (Col-0) seedlings and pp2c19-1 and pp2c19-2 mutants were preirradiated with overhead RL irradiation for 2 min at 20 µmol m^–2 s^–1 2 h before BL irradiation and subsequently irradiated with unilateral BL at 0.17 µmol m^–2 s^–1 for the indicated periods. Proteins (10 μg) extracted from the seedlings were separated via 7.5% SDS-PAGE, followed by immunoblotting with the indicated antibodies. (b) Time-course analysis of NPH3 protein changes in response to BL irradiation. Two-day-old etiolated seedlings of wild-type (Col-0) seedlings and pp2c19-1 mutants were preirradiated with overhead RL irradiation for 2 min at 20 µmol m^–2 s^–1 2 h before BL irradiation and subsequently irradiated with unilateral BL at 0.17 µmol m^–2 s^–1 for the indicated periods. (c) Signal intensity ratio of the upper band to the lower band in the immunoblotting using the anti-NPH3 antibody in Fig. 4b. Data shown are mean ± SE from three independent experiments. Asterisks indicate statistically significant differences (two-tailed Student’s t test, P < .05). Signal intensity ratios at 0 min were significantly larger than those at other time points; therefore, they were omitted from the graph. (d) Time-course analysis of NPH3 protein changes in response to BL irradiation and subsequent dark incubation. Two-day-old etiolated seedlings of wild-type (Col-0) seedlings and pp2c19-1 mutants (−15 min) were irradiated with unilateral BL at 0.17 µmol m^–2 s^–1 for 15 min (0 min) and then incubated under darkness for the indicated periods. (e) Signal intensity ratio of the upper band to the lower band in the immunoblotting using the anti-NPH3 antibody in Fig. 4d. Data shown are mean ± SE from three independent experiments. Asterisk indicates a statistically significant difference (two-tailed Student’s t test, P < .05).