Figure 7.
Epidermal phyB Non-Cell-Autonomously Promotes the Phosphorylation and Degradation of Endodermal PIF3.
(A) Epidermal phyB induces the degradation of endodermal PIF3. Dark-grown seedlings were transferred to red light (9 μmol m−2 s−1) for 30 min, 1 h, or 2 h (R30, R1 h, or R2 h) before being sampled to measure endodermal MYC-tagged PIF3 levels using an anti-MYC antibody. PIF3MYC indicates endodermal MYC-tagged PIF3, while p-PIF3MYC indicates the slower-migrating phosphorylated form. TUB indicates α-tubulin. The asterisk indicates nonspecific bands. The lower panel is an independent experiment with a longer exposure.
(B) Epidermal phyB induces phosphorylation of endodermal PIF3. Dark-grown seedlings were transferred to red light for 15 min before sampling. Precipitated PIF3MYC proteins were treated with either CIP or boiled CIP (boiled). MYC-tagged PIF3 was detected using an anti-MYC antibody. The asterisk indicates nonspecific bands.