The role of membrane surface charge in the control of photosynthetic processes and the involvement of electrostatic screening

Three-Dimensional Organization of Higher-Plant Chloroplast Thylakoid Membranes Revealed by Electron Tomography

“…The average thickness of the granum layers is 20 nm 6 2 nm, which is also the thickness of the flanking stroma lamellae. Within the granum, the surfaces of adjacent layers or discs are separated by 3 to 4 nm, in agreement with previous reports (Nir and Pease, 1973;Arntzen and Briantais, 1975) and in line with predictions made by electrical double-layer theories (Rubin and Barber, 1980;Dubois et al, 1991). Note that the granum layers, while presenting a distinct granular texture, are topologically continuous with the stroma membranes that penetrate the granum at multiple levels.…”

An explanation for the relationship between salt‐induced thylakoid stacking and the chlorophyll fluorescence changes associated with changes in spillover of energy from photosystem II to photosystem I

“…As already emphasised in a number of publications from my laboratory the above properties indicate that the cation-induced chlorophyll fluorescence and thylakoid stacking changes must be controlled by a general electrostatic phenomenon rather than some specific chemical mechanism [12,18,28,29]. Attempting to find explanations for the cation-induced effects we, and Duniec et al [30] have turned our attentions to the established electrostatic theory of Gouy and Chapman [3 1,321 and in particular the application of this theory to the concepts which underlie the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of stability of lyophobic colloids [33].…”

“…When electrostatic screening is high then charged surfaces are able to approach each other. We have shown that the sensitivity of chlorophyll fluorescence and thylakoid stacking to different cation levels, types and mixtures, can be correlated with changes in electrostatic screening as determined by calculation of the integrated space charge density adjacent to the membrane surface [28,29]. Duniec et al were also able to predict the experimental findings for mixed electrolyte conditions using an extension of the DLVO approach [30] and we too have equated our calculations with a force parameter [29,34] In order to attempt to answer the above question and formulate a model the following properties must be considered :…”

Acclimation of leaves to low light produces large grana: the origin of the predominant attractive force at work

“…(iii) Adjacent to each domain of one type of charge, the magnitude of the surface charge density may be much greater than that of the net surface charge density s on the membrane surface overall; in that case, the electric field strength E near the surface may be strong enough to align water dipoles. Our unpublished calculation of E according to the Gouy -Chapman theory [39] for an unstacking buffer medium gave an E value at the surface such that a water dipole placed in the electric field has an energy of about 22kT, where k is Boltzmann's constant. On the other hand, in a stacking buffer medium such as one containing MgCl 2 (which is abundant in the chloroplast stroma), E is fourfold smaller, so that a loss of alignment of water dipoles is expected.…”