Regulation of Ferricyanide Reduction by Epidermal Tissue

Ferricyanide reduction by epidermal strips of Commelina communisis stimulated by plasmolysis, and this stimulation is partiallyreversed by re-hydration. The reduction of ferricyanide takesplace only in the guard cells. KCN stimulates ferricyanide reduction, indicating that NADHserves as an electron donor. Catalase, which inhibits NAD(P)Hdriven oxygen uptake Askerlund et al. (1987) Physiol. Plant.71: 9–19., Pantoja and Willmer (1988) Planta 174: 44–50.]enhances ferricyanide reduction and this stimulation is evidentmainly in the non-plasmolysed tissues. Differences between thenon-pretreated tissues and the plasmolysed ones are discussed. (Received July 11, 1989; Accepted November 2, 1989)