Studies in the Metabolism of Plant Cells IX . The Effects of 2,4-Dlnitrophenolon Salt Accumulation and Salt Respiration

Abstract

Summary 2,4-Dinitrophenol, while increasing the respiration, inhibits the accumulation of ions by carrot cells. Further investigation is necessary to determine whether the inhibition is due to a direct effect of the dinitrophenol on the mechanism or whether the dinitrophenol indirectly prevents the mechanism from operating by causing some disorganization within the cell, possibly in the mitochondria. If the assumption that dinitrophenol inhibits phosphate transfers is justifiable, hypotheses of salt accumulation might require modification to allow for the participation of energy-rich phosphate. This would suggest that the Lundegardh mechanism may be a part of a more complex mechanism.

Respiration and Salt Absorption by Excised Barley Roots.

“…The concentration of salt in the immediate vicinity of the root is unknown. The data of Robertson and Turner (17) indicating that no loss of salt already accumulated takes place when the accumulation mechanism is poisoned by cyanide are manifestly in conflict with this interpretation.…”

“…Further speculation as to the exact nature of the binding compounds is perhaps unwarranted. However, the response of respiration and absorption to the inhibitor 2,4-dinitrophenol may suggest that the alternate pathways involve phosphorylated compounds (20 3. The values of the ratio, anions absorbed/02 consumed in salt respiration, were calculated for various external concentrations of KBr, NaBr, and CaBr2.…”

Kinetics and Energetics of Light-enhanced Potassium Absorption by Corn Leaf Tissue

“…Cyanide and unoouplers of oxidative phosphorylation, DNP, mC4-CCP, or NaN3 (1,11,12,18,19,32), manifested their greatest effect in the dark when a large percenitage of ATP is probably formed by respiratory processes. A'bsorption in the dark was less than 20 % of thiatt of the cTontroil when DNP, mCl-cCP, or NaN3 was present.…”

Conceptual Developments in Membrane Transport, 1924-1974

“…Another point is that agents, e.g. dinitrophenol, which uncouples phosphorylation from respiration, block ion uptake while greatly enhancing 02 uptake and terminal oxidation (64,87). Further (7) where R is the gas constant (joules -degree eq.-'); T, the temperature; z, the valence of the mobile ion; F, the Faraday constant (coulombs eq.-'); and X is the ratio of the concentrations of the mobile ion (counter to the immobile ion) between the two phases.…”