Potassium inhibition of calcium and magnesium accumulation in roots of intact maize seedlings

Abstract

The effects of solution potassium (K) on the accumulation of magnesium (Mg) and calcium (Ca) in roots was assessed with 7‐day‐old corn (Zea mays L.) seedlings. Root accumulation of Ca and Mg was studied in replacement type experiments, i.e. the ratio of Ca to Mg was altered but the concentration of Ca plus Mg was kept constant at 2 mM. Concentrations of Ca in the tissue after 12 h exceeded that of Mg, except when Mg comprised over 85% of the divalent cations in the uptake solution. The addition of 0.1 mM K to the Uptake solutions significantly altered the accumulation of Ca and Mg. The concentration of Mg was affected more than that of Ca. The relative effects of solution K on Mg and Ca accumulation in roots could be explained by comparing the relative acid‐base characteristics of the metals.