Brykov V. Reactions of mitochondria in Pisum sativum L. root cells to clinorotation

The results of investigations of the structure and function organization of mitochondria in pea seedlings of different age under slow horizontal clinorotation are presented. In the meristem and central elongation zone, the mitochondrion ultrastructure is similar to that in the control, while mitochondria become condensed in the distal elongation zone. The intensity of the mitochondrion ultrastructure changes is dependent on the duration of clinorotation, and at the 5th day of clinorotation, the changes in the mitochondrion ultrastructure are accompanied with increased respiration of root apices by 7%. It was established the changes in functioning of the oxidative phosphorylation system in isolated mitochondria. Under clinorotation, the efficiency of oxidative phosphorylation decreases that is accompanied with increasing both the rate of substrate oxidation and respiratory control ratio. Such changes in mitochondrion metabolic activity are considered to be an adaptive character and provide root cell energetic homeostasis under clinorotation.