Short-term effects of Mn2+ on elongation growth and H+ -extrusion in Zea mays L. coleoptile segments

The effect of 10-2-10-6 M Mn+2 on the growth and acidification of the incubation medium by Zea mays L. coleoptile segments was studied. It is shown that 10-5M manganese stimulated growth (in comparison to a control without Mn+2) while concentrations from 10-2 to 10-4M clearly inhibited it. It was also found that manganese at the studied concentration range significantly inhibited acidification of the incubation medium. Auxin, at a concentration of 10-5M, reversed the inhibitory effect of Mn+2 (with the exception of 10-2M) on the growth and acidification of the incubation medium by Zea mays L. coleoptile segments