Abstract
Rubidium absorption and respiration of excised etiolated pea stem, potato and Jerusalem artichoke tuber were studied as influenced by inorganic phosphate, dinitrophenol (DNP) and arsenate. Within the limits of the present study the effect of added phosphate on Rb+ uptake was negligible. DNP and arsenate, within the concentration range used, gave enhanced aerobic respiration, but depressed Rb+ uptake. Under these conditions Rb+ uptake was inversely related to O2 consumption. The same concentration range of DNP enhancing respiration also depressed Rb+ (and H2PO4-) uptake. This is consistent with the hypothesis that DNP and arsenate block ion uptake by interfering with a necessary high energy phosphate hydrolysis.