THE PECULIARITIES OF WHEAT ROOT CELLS FUNCTIONING UNDER INHIBITION OF I AND II COMPLEXES OF MITOCHONDRIAL
RESPIRATORY CHAIN
O. O. Polygalova,1 E. N. Bufetov, A. A. Ponomareva
Institute of Biochemistry and Biophysics, Kazan' Scientific Centre of RAS;
1 e-mail: bufetov-en@mail.ru
A joint effect of rotenone and malonate on the intensity of respiration, output of K+ and ultrastructure of wheat
root cells treated for 6 h was studied. The addition of malonate to rotenone containing solution, in which wheat roots
had been incubated for an hour, caused further decrease in respiration intensity and K+ output into
external medium. Many mitochondria acquired torus shape in 2h after malonate addition. The increase in respiratory
intensity and re-entry of K+ from the incubation medium into the cells were observed during following hours
of incubation. We assume that reparation and adaptation processes took place in this case. The observed contacts of
endoplasmic reticulum lumens with mitochondria are indicative of possible synthesis of an enzyme able to metabolize
malonate to acetyl-CoA and CO2. We propose that torus shape of mitochondria is due to the increase in their
outer surfaces, that, in turn, is a result of activation of external NAD(P)H-dehydrogenase. These findings may be
evidence of possible adaptation of the root cells to the joint effect of the inhibitors.
Key words: respiration, rotenone, malonate, succinate dehydrogenase, external NAD(P)H-dehydrogenase,
torus shape mitochondria
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