Fig. 1.

The CRY2-interacting bHLH protein CIB1 is degraded in the absence of blue light. Immunoblots show the expression of the CIB1 protein in transgenic plants expressing the 35S::Myc–CIB1 transgene. Samples were fractionated by 10% SDS/PAGE, blotted, probed with the anti-Myc antibody, stripped, and reprobed with the anti-CRY1 antibody as the loading controls. (A–C) Plants were grown in CW for 3 wk, transferred to dark (A) or red light (20 μmol⋅m⁻²⋅s⁻¹) (B) or remained in CW (C) for 16 h, and then transferred to blue light (35 μmol⋅m⁻²⋅s⁻¹) for the indicated time before sample collection. (D–F) Three-week-old plants were grown in CW, transferred to continuous blue light (blue, 35 μmol m⁻² s⁻¹) for 16 h, and then transferred to dark (D), red light (20 μmol⋅m⁻²⋅s⁻¹) (E), or far-red light (5 μmol⋅m⁻²⋅s⁻¹) (F), respectively, for the indicated time before sample collection. (G and H) Results of a fluence rate response showing the CIB1 protein expression changes in response to blue light. Plants were grown in continuous red light for 3 wk and then transferred to blue light of indicated fluence rate (1–40 μmol⋅m⁻²⋅s⁻¹) and time indicated before sample collection. (H) The immunoblots shown in G were analyzed by the quantitative Odyssey analysis.