THE INFLUENCE OF PROTONOPHORE HIGH CONCENTRATION ON THE STRUCTURE AND FUNCTIONS OF WHEAT ROOT CELLS
A. A. Ponomareva,1 O. O. Polygalova
Institute of Biochemistry and Biophysics, Kazan' Research Centre RAS, Kazan';
1 e-mail: ponomareva@mail.knc.ru
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 Δµ H+ in plasma membrane. Within the
first 5-10 min of exposure of 50 µM 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.
Key words: mitochondria, excised roots of wheat, protonophore, cell ultrastructure, energy supply
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