Response of the plant root to aluminum stress: Analysis of the inhibition of the root elongation and changes in membrane function

Abstract

Pea root elongation was strongly inhibited in the presence of a low concentration of Al (5 μM). In Al-treated root, the epidermis was markedly injured and characterized by an irregular layer of cells of the root surface. Approximately 30% of total absorbed Al accumulated in the root tip and Al therein was found to cause the inhibition of whole root elongation. Increasing concentrations of Ca2+ effectively ameliorated the inhibition of root elongation by Al and 1 mM of CaCl2 completely repressed the inhibition of root elongation by 50 μM Al. The ameliorating effect of Ca2+ was due to the reduction of Al uptake.