Calcium ameliorates effects of lead in protonema of Funaria hygrometrica Hedw.

Abstract

Two-days-old in vitro grown protonemata of Funaria hygrometrica Hedw. were treated with a mixture PbCl 2 (4 μM Pb 2+) and CaCl 2 (16 μM Ca 2+) (Ca+Pb) for 48 h. The results were compared with the control: distilled water (H 2O) and the solution of PbCl 2 (4 μM Pb 2+) (Pb). Protonemata treated with Ca+Pb were longer and contained more cells than those treated with Pb. Moreover, a lower number of cells showed apical cell deformations typical for lead toxicity: swollen tips and wall thickenings at the apex. If deformations were present they were not as extended as in Pb. In comparison with the control, however, protonemata treated with Ca+Pb were shorter, contained a lower number of cells and some apical cells in this material were altered. It can be concluded that the presence of calcium partially neutralised toxic effects of lead in Funaria hygrometrica protonemata cells.