Figure 8. A model for phosphorylation- and cation-dependent stacking of plant photosynthetic membranes.

Deficiency in light-induced phosphorylation of PSII in the stn8 and stn7stn8 mutant plants cause enlargement of grana and loss of the cation-dependent stacking of thylakoids (left). Presence of at least one phosphoryl group per PSII in the wild type thylakoids causes electrostatic repulsion of the adjacent grana membranes (center) and makes their stacking highly cation-dependent (right).