FIGURE 3.

Specific loss of PSI core complex in maize and Arabidopsis psa2 mutants. A, immunoblot analyses of thylakoid proteins in maize (Zm-psa2-1) and Arabidopsis (At-psa2-1) mutants. A dilution series of material from wild-type siblings was included to aid in quantification. The panel to the right shows the results from maize seedlings that had been dark-adapted for 12 h. Antibodies were directed against PsaA, PsaF, PsaG, PsaK, and PsaD (PSI core subunits); Lhca1 and Lhca2 (PSI antenna proteins); D1, D2, and CP43 (PSII core subunits); Lhcb1 (PSII antenna protein); subunit of the cytochrome b₆f complex (Cyt f), and CF₁αβ (the α and β subunits of the membrane extrinsic portion of the ATP synthase complex). B, BN-PAGE analysis of thylakoid membrane complexes in maize and Arabidopsis psa2 mutants. Bands were assigned as the PSII-light-harvesting assemblies (PSII-LHCII), monomeric PSI (PSI-M), PSII dimer (PSII-D), PSII monomer (PSII-M), and trimeric light-harvesting complex II (LHCII-T) based on prior reports (26, 62, 63). Panels to the right show immunoblots of BN-PAGE-separated thylakoid proteins from wild-type and mutant maize seedlings.