[The influence of protonophore high concentration on the structure and functions of wheat root cells]

Protonophore induced structural and functional changes in cells of excised roots of wheat seedlings have been investigated. The vector transfer of H+ inside the cells was accompanied by a decrease in energy supply of these cells (suppression of oxygen consumption and heat release), an output of K+ ions to the incubation medium, and by an increase in its pH value. The initial increase in heat release by roots (1 h) apparently reflects the process of dissipation of deltamicro H+ in plasma membrane. Within the first 5-10 min of exposure of 50 microM CCCP, changes in cell ultrastructure were observed that involved activation of Golgi apparatus, secretion of vesicle contents to the vacuole, and swelling of endoplasmic reticulum canals. Following a 2 h treatment with CCCP, structural and functional changes acquired a destructive character, and after 5-6 h of treatment with protonophore a complete desintegration of cell structure occurred demonstrating formations of myelin-like bodies, fragmentation of plasma membrane, and destruction of the nucleus. Thus, the protonophore induced proton excessive transport inside cells is fast and may cause an irreversible cell de-energization followed by serious disruption of ultrastructural organization of cells leading eventually to their death.