Metabolic Changes Associated with Ferricyanide Reduction by Elodea Leaves
It has been shown that ferricyanide reduction by Elodea densa leaves, in the dark, is associated with a decrease of intracellular pH, a marked depolarization of the transmembrane potential and a net efflux of H+ and K+. The sum of (H+ +K+) extruded is approximately equal to the amount of Fe(CN) 6 3− reduced. Fusicoccin (FC) increases both Fe(CN) 6 3− reduction and the associated efflux of H+ and decreases K+ efflux. This effect is interpreted as a consequence of the hyperpolarizing, cytoplasm alkalinizing action of FC, due to its capacity to activate the ATP-driven H+ pump. The results of a preliminary analysis of the metabolic changes associated with these responses of transport mechanisms to either FC, or Fe(CN) 6 3− , or both in combination, can be summarized as follows.