Photosynthetic properties of ?rpoZ. (A) Light-saturated photosynthetic activity of a 1 ml of culture (OD730 = 1) of CS (white bar) and ?rpoZ (black bar) in standard conditions. Each bar represents an average of three independent biological replicates, and the error bars denote SE. (B) Fluorescence at 77 K was measured using 440-nm light that excites Chl. The data were normalized by dividing with the height of the PSI emission peak at 723 nm. (C) Total proteins were isolated, separated with SDS-PAGE and the amounts of PSI reaction center protein PsaB, PSII core protein CP43 and the phycobilisome proteins allophycocyanin (APC) and phycocyanin (PC) were measured by western blotting. The protein contents of PsaB, CP43, ACP and PC were 99 ± 6%, 97 ± 7, 103 ± 7% and 99 ± 4, respectively, in ?rpoZ of that measured in CS.

Changes of PSII and PSI antenna and core protein levels. Proteins from control and Tl-treated white mustard leaves were separated by SDS-PAGE followed by immunodetection with antibodies against Lhcb1, Lhcb2, Lhca1 (antenna proteins) and D1, D2, CP43, PsbO, PsaA (core proteins). Samples were loaded on the equal amount of chlorophyll (0.25 ?g). Description of samples abbreviation as given in the legend to Fig. 3

Analysis of PSII complexes and subunits in Col-0 and vir-1 seedlings.a BN-PAGE and immunoblot analysis of thylakoid photosynthetic complexes. Equal amounts of thylakoid membrane (10 μg chlorophylls) from Col-0 and vir-1 seedlings under 0-h (GL) and 24-h (HL) high light treatment were solubilized with 2% n-dodecyl-β-D-maltoside (DM) and separated by BN-PAGE. The BN-PAGE gel was stained with Coomassie brilliant blue (CBB). The macromolecular protein complexes of thylakoid membranes (indicated on the left) were identified according to Jin48. For BN-PAGE immunoblot analysis, an equal amount of chlorophyll (1.5 μg) was loaded in each lane, and anti-D1, anti-D2, anti-CP43, and anti-CP47 antisera were used to probe the PSII complex. I: PSII-LHCII supercomplex; II: PSII dimer, PSI monomer; III: PSI monomer, CF1; IV: Cyt b6f, PSII core monomer; V: CP43-less PSII core monomer; VI: LHCII trimer. All experiments involved three independent biological replicates, which produced similar results. b Proteins immunodetected from (a) were quantified with Phoretix 1D software (Phoretix International, UK). Values (mean ± SE, n = 3 independent biological replicates) are given relative to protein levels of Col-0 before HL treatment. *P < 0.05; **P < 0.01, by two-sided Student’s t test. c, Analysis of thylakoid membrane protein accumulation in Col-0 and vir-1 mutants. Thylakoid membrane proteins from Col-0 and vir-1 seedlings were separated by 12% SDS-urea-PAGE and probed with antisera against specific thylakoid membrane proteins. Samples were loaded on an equal chlorophyll basis. Cyt b6f, cytochrome b6f complex; LHC, light-harvesting complex; ATPase, ATP synthase complex. Similar results were obtained from three independent biological replicates. d Proteins immunodetected from (c) were quantified with Phoretix 1D software (Phoretix International, UK). Values (means ± SE; n = 3 independent biological replicates) are given relative to protein levels of Col-0 before high light treatment. *P < 0.05; **P < 0.01, by two-sided Student’s t test.