Figure 4.

phyB Is Unstable in Nuclei under R Light.

(A) Nuclear phyB is unstable under R light. Two-week old wild-type (Col-0) Arabidopsis plants grown under long days (16 h light/8 h dark) (M) as well as 4-d-old etiolated seedlings that were kept in the dark (D) or transferred to R light for 6 or 24 h (R6 and R24, respectively) were fractionated.

(B) Nuclear phyB levels can be increased by MG132 (25 μM) under R light.

(C) NGG-NLS is localized in nuclei under R light. Four-day-old etiolated seedlings (NGG-NLS/B-) were treated with MG132 (25 μM) and then kept in D or exposed to R light (10 μmol m⁻² s⁻¹) for 24 h.

In (A) to (C), samples were fractionated as soluble (S) and nucleus (N). Pol II and tubulin were used as the marker proteins for nuclear and cytosol fractions, respectively, as well as the loading controls.