ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Mutual dependence of mineral nutrition and water balance in plants

M. Toman

Forschungsinstitut für agrochemische Technologie in Bratislava

Abstract: The mineral nutrition of Ca²⁺, Mg²⁺, K⁺, Na⁺, H⁺, SO₄^2-, NO₃^-, H₂PO₄^-, HPO₄^2-, Cl-, and water balance in plant tissues was studied. The active ion transport theory and its relation to electrochem. potential gradient and ion exchange were discussed. The lack of consistency of the present theories in the mutual relationship of water balance, intensity of cell metabolism, intensity of active ion transport within living tissues and lack of differentiation between the function of uni-, bi-, and tri-valent cations is pointed out. In the study of the behavior of living cell, imbedded in an ionized environment, the classical concepts of diffusion, of moving equil. of the concns. within the cell and environment, Donnan's equil. (cf. C.A. 6, 1559), electro.ovrddot.osmosis and finally the Le Chatelier-Braun principle, explaining the antagonism of bivalent cations, was applied. To explain the mutual interaction of both cations (Mg²⁺, K⁺, Na⁺, H⁺) and anions (SO₄^2-, NO₃^-, H₂PO₄^-, HPO₄^2-, and Cl^-), and water in the field of transfer (i.e. cell/environment), the concept of ion synergism is defined, explaining the noncompetitive interaction of ions of both types, shown in a graph and compared with so-called carrier effect of Ca²⁺ , Mg²⁺ , and H₂PO₄^-. The author's conclusions are that the behavior of the cell-water-ions system is the result of simultaneous actions of water mols., ion flows, and ion exchanges. The diversity of electro.ovrddot.osmotic pressures is a function of both (elec.) potential gradients and spatial allocation of (plasma) gel network. Electro.ovrddot.osmotic pressures and osmotic pressures are additive. The flow of the liquid phase through a pore (of the cell) in both directions is explained by an elec. field which transfers an ion of high mobility in the cell against the direction of the flow of liquid carrying ions of lower mobility. The mosaic structure of plasma introduced by T. serves as an explanation of low intensity of accumulation of both bivalent cations and anions.

Full paper in Portable Document Format: 85a294.pdf (in Czech)

Chemical Papers 8 (5) 294–324 (1954)