biologia plantarum

Biologia plantarum 15:241-249, 1973 | DOI: 10.1007/BF02922704

Study of oxidative and phosphorylative activity in mitochondria from cereal seedlings

F. Plhàk¹

¹ Department of Plant Biology, Faculty of Science, J. E. Purkyně University, Brno, Czechoslovakia

In the present paper the oxidative and phosphorylative activity of mitochondria isolated from rye, wheat, barley and corn seedlings are compared. Mitochondria from the shoots as well as from the roots of rye, wheat and corn oxidized succinate and in the presence of ATP or ADP exhibited the respiratory control which reached the values mostly of about 2. In the presence of ATP or ADP the decrease of inorganic phosphorus was contemporarily remarcable. The P/O ratio reached the values mostly of about 0.8 up to 1.0. The presence of ATP effected in some cases more favorable the respiratory control as well as the P/O ratio in comparison with ADP. With regard to the fact that a trapping hexokinase system was not added, the presence of endogenous hexokinase in mitochondria of experimental plants is presumed. The barley mitochondria exhibited the respiratory control as well, but instead of the decrease in inorganic phosphorus content in reaction mixture, an increase took place. It was caused by the presence of active ATP-ase which was not effectively inhibited by present NaF.

Received: June 16, 1972; Published: July 1, 1973  Show citation