Effect of nickel on proton extrusion in segments of maize seedling roots

Abstract
Nickel affects the proton extrusion capacity in segments of maize seedling roots; as in the field condition, this effect is enhanced by phosphate and counteracted by Ca++ and Mg++. The effect of nickel on the proton‐extruding activity can explain either nickel toxicity and its stimulating effect on plant growth. Such hypothesis is discussed in this paper.