Toxicity of triethyllead chloride (TriEL) on cytoplasmic shuttle streaming, structure, growth and migration of the plasmodial slime mold Physarum polycephalum

Lead is one of the poisonous heavy metals that affects the biotic system. In this research, the toxic effects of different concentrations of triethyllead chloride( TriEL ) was studied on the acellular slime mold Physarum polycephalum cytoplasmic shuttle streaming, growth, structure and migration of Physarum plasmodium. The plasmodium was treated with different concentrations of TriEL ( 10, 20, 30, 40, 50 and 60 μM). The results showed that concentrations of TriEL 10 μM had no obvious effect on the studied parameters. Initial or slight signs of toxicity appeared at Concentrations between 20 - 50 μM. However, 50 μM TriELwas sublethal. They caused mostly irreversible condensation of the plasmodial strands, blebbing of the plasma membrane, vacuolization of the cytoplasm and elongation of the cytoplasmic shuttle streaming period. 60 μM TriEL was lethal and caused irreversible high blebbing of the plasma membrane, direct and rapid stop of cytoplasmic streaming followed by contraction of the whole plasmodium, strong blebbing of the plasma memmbrane, depigmentation, vacuolization and complete fixation of the cytoplasm (neither growth nor migration occurred on nutrient agar plates).