THE INFLUENCE OF CYCLIC HEAT-SHOCK ON FOR MATION OF MEMBRANE SYSTEM IN BARLEY ETIOPLASTS

Shortening of leaves and coleoptiles, increase in the etioplast volume and the total length of prothylakoid membranes was observed in etiola ted barley plants after cyclic heat shock (HS). HS stimulated protochl orophyllide and carotenoid accumulation, increase in intensity of tryp tophane fluorescence and the eximerisation degree of lipophilic fluore scent probe pyrene in prolamellar body fraction (pel. total protein). The latter is most likely to be caused by a decrease in microviscosity of the membrane lipid bilayer and not by pigment-mediated quenching o f pyrene eximer fluorescence.