The relationship between cation-induced fluorescence and membrane stacking in isolated spinach chloroplasts.

In order to study the relationship between Mg(++)-induced fluorescence and membrane stacking, trypsin was used as a probe. Trypsin treatment diminished to a high degree the light-induced variable fluorescence and membrane stacking. Mg(++) markedly increased the fluorescence yield near 680 nm and membrane stacking. Pretreatment of chloroplasts with Mg(++) eliminates the effect of trypsin on cation-induced fluorescence change but not on the membrane stacking. The results presented in this contribution support the evidence that the cation-induced membrane stacking and the fluorescence yield are not linked.