Figure 5. Thylakoid ultrastructure.

Representative transmission electron micrographs are shown for leaf chloroplasts from 8-week-old wild-type (wt) plants and vccn1-1 mutant fixed after 16 h of darkness or 3 h after the onset of illumination (150 μmol photons per m² per s). The mutant shows consistently longer thylakoid stacks (grana) than wt in the dark state. In light conditions, the grana of vccn1-1 are also longer, but often display a curved ‘banana-like' shape (observed in 20–50% of the studied plastid sections). Scale bars, 1 μm (upper panels) and 200 nm (lower panels).