Comparison of calcium and lanthanon Ions in the Avena-coleoptile growth test.

Inhibition of elongation of oat coleoptile sections by La(3+), Pr(3+), and Nd(3+) is similar to but greater than that by Ca(2+) at low and intermediate concentrations. The lanthanons might serve as probes to learn more about the manner of action of Ca(2+), a normal growth-regulating agent.