Fig. 2. Synthesis of CP47 is reduced and PSII assembly is retarded in fpb1 and pam68.

a Polysome association studies of WT, fpb1, and pam68 plants in the absence (left) and presence (right) of puromycin. Whole leaf extracts from three-week-old plants were separated by centrifugation in 15–55% sucrose density gradients. RNA isolated from the gradients was probed with DIG-labelled probes corresponding to the psbB and psbEFLJ mRNAs. Approximate sizes of main bands are shown and the corresponding band sizes can found in Supplementary Fig. 4a. b, c Protein labelling with [³⁵S]-Met. Primary leaves of 12-day-old young seedlings were incubated with cycloheximide and then radiolabelled with [³⁵S]-Met for 20 min. Labelled thylakoid proteins were separated using 12.5% SDS-urea-PAGE (b) and 16% Tricine-SDS-PAGE (c). The signals were detected by exposure to X-film. Overexposure from the same gel was used for higher visibility of CP47 (right in b). The PsbH protein was detected as a band smaller than 10-kDa as in ref. ¹⁵, in which the synthesis of PsbH (~8 kDa) was reported to be completely blocked in the hcf107 mutant. d Pulse-chase labelling of thylakoid proteins. Proteins were labelled as in (b) for 20 min (indicated as 0) and then chased with unlabelled Met for 15 and 60 min. Thylakoid proteins were separated and visualized as in (b). Overexposure of the same gel was used for detecting CP47 (bottom). e Immunoblot analysis of pD1 and CtpA. During illumination, 12-day-old young seedlings were frozen in liquid N₂ immediately and thylakoids were isolated. Equal amounts of total thylakoid proteins were separated using SDS-urea-PAGE and then probed with antibodies. CF₁γ was used as a loading control. f Assembly kinetics of PSII in fpb1, pam68, and WT plants. Thylakoid proteins were labelled for 20 min (indicated as 0) and subsequently chased for 10 and 30 min. Labelled proteins were separated by 2D BN/SDS-urea-PAGE and detected using autoradiography. PSII SC, PSII supercomplexes. PSII RC, PSII reaction centre. Data are representative of two independent biological replicates. Source data are provided as a Source Data file.