Rubisco and PsbS protein levels in initiation factor mutants. WT, eif4e, eifiso4e, eif4g, eifiso4g1, eifiso4g2, eif4g/eifiso4g1, and eifiso4g1/2 mutants were grown at a PFD of 250 PFD for to a similar developmental stage, and the levels of PsbS and RbcL were determined using Western analysis and compared with eIF4A on a fresh weight basis.