Figure 2.

phyA Colocalizes with SPA1 in Arabidopsis Nuclear Bodies.

(A) Epifluorescence microscopy visualization of phyA-CFP and HA-YFP-SPA1 in hypocotyl cells of stable cotransformed ProPHYA:PHYA-CFP and Pro35S:HA-YFP-SPA1 Arabidopsis plants. Seedlings were grown for 4 d in darkness and treated with either no light (D), 6 h FR light, or 6 h FR followed by 6 h R light (FR + R). Additionally, 4-d-old etiolated seedlings were fixed with formaldehyde prior to microscopy (D - fixed).

(B) Immunoelectron microscopy localization of phyA in wild-type Arabidopsis Col-0 hypocotyl nuclei. Seedlings were grown in darkness for 4 d and treated with 6 h FR light followed by 5 min R light prior to fixation. Endogenous phyA was probed with α-phyA antibodies and detected with protein A-labeled 6-nm gold particles (indicated by arrow). Upper panel: overview (nucleus). Lower panels: enlarged areas (nuclear bodies). Bar = 200 nm.

(C) Epifluorescence microscopy visualization of phyA-CFP expressed from ProPHYA:PHYA-CFP in phyA-211, spa1-7 spa2-1 spa3-1 (spa123), and cop1-4 Arabidopsis backgrounds. Seedlings were grown in darkness for 4 d, followed by 6 h FR. Bars in (A) and (C) = 4 μm.