title: Light Induced Polarity of Redox Reactions in Leaves of Elodea canadensis Michx.
abstract: This paper reports that extracellular reductase activity in leaves of Elodea canadensis, hitherto never associated with polar processes thought to be involved in bicarbonate utilization, also shows a very marked polarity in light. The effect of ferricyanide, applied to the lower side of illuminated leaves, was a depolarization of the membrane electrical potential of up to 110 millivolts, while no depolarization was induced when ferricyanide was applied to the upper side. In the dark ferricyanide induced a depolarization when applied to either the upper or to the lower side of the leaf. Staining with tetrazolium salts, specific indicators for reductase activity, resulted in the formation of a precipitate on the lower side of the leaf when illuminated and on both sides in the dark. The precipitate was only located along the plasmalemma.
authors: University of Groningen, Department of Plant Physiology, P. O. Box 14, 9750 AA Haren, The Netherlands.
authors: J T
authors: JT
authors: Elzenga
authors: H B
authors: HB
authors: Prins