Figure 5.

Abolished synthesis of CP47 in the ΔpsbH/Δpam68 mutant is rescued by enhanced Chl biosynthesis. A, The ΔpsbH/Δpam68 cells grown mixotrophically were harvested and resuspended in a growth medium without Glc. The obtained culture was divided into two flasks, with one of them supplemented with N-methyl-mesoporphyrin IX (Me-MesoP, FeCh inhibitor). The photoautotrophic growth was then monitored. The inset shows the same growth experiment but with 200 nm Me-MesoP added into the plate. B, Absorbance spectra of mutant cells growing for 4 d in the presence or absence of FeCh inhibitor. Spectra were normalized to light scattering at 750 nm. Also shown is the Chl content determined spectroscopically in methanol extract and normalized per OD_{750 nm}. C, ΔpsbH/Δpam68 cells grown for 2 d photoautotrophically in the presence of 200 nm FeCh inhibitor were radiolabeled with a mixture of [³⁵S]Met/Cys; incorporation of radioactivity into core PSII subunits was detected after 2D CN/SDS-PAGE. The same amounts of Chl were loaded of each sample. a.u., absorbance units; d.t., doubling time; iD1, incompletely processed form of the D1 precursor; PSI[3], trimer of PSI; PSII[1], monomer of PSII; PSII[2], dimer of PSII; RCII*, assembly intermediate (reaction center complex) lacking CP47m (Knoppová et al., 2014); RCIIa, PSII assembly intermediate (reaction center complex) lacking CP43m (Knoppová et al., 2014).