[Effect of temperature on the photo-induced pH gradient in isolated chloroplasts]

Experimental data are presented on the change of photoinduced proton transport and velocity of electron transport (according to photoreduction of K3Fe(CN)6) in chloroplasts during heating within the temperature range 25-50 degrees C for 3 and 5 min. Preliminary heating of chloroplasts irreverssibly supresses the ability of chloroplasts membrane to bind the protons. The velocity of electron transport decreases with the increase of heating temperature, the value of photoinduced change of pH also decreases. Heating is suggested to affect the electron transport chain. The velocity of electron transport decreases and induces the inhibition of proton transport. Presence of detergents, such as digitonin and triton X-100 in chloroplast suspension in concentrations not higher then 0.02% supresses the process of photoinduced change of pH.