Effects of Al3+ on the nucleolus in root tip cells of Allium cepa

Abstract

The effects of different concentrations of aluminium chloride on the nucleoli in root tip cells of Allium cepa were studied using the silver staining technique. The concentrations used of aluminium chloride (AlCl3) were 1.0 × 10‐5, 5.0 × 10 ‐5, 1.0 × 10 4, 5.0 × 10 4, 1.0 × 10‐3, 5.0 × 10‐3, 1.0 × 10‐2, 5.0 × 10‐2, and 1.0 × 10‐1 M. After the treatment with Al3+, the nucleolar material was extruded from the nucleus into the cytoplasm. The phenomenon was observed in both the inner root meristem cells and the root cap cells. But there were differences between the two regarding the shape and position of the silver‐stained material in the cytoplasm. The present observations with the silver staining technique confirm the phenomenon observed for the first time by FlSKRSJO (1983). The possible mechanism behind this phenomenon is also briefly discussed. Copyright © 1992, Wiley Blackwell. All rights reserved