Ultrastructural responses of leaf mesophyll and trap wall cells of Utricularia vulgaris to cadmium

Ultrastructure of leaf mesophyll and two-layer trap wall of Utricularia vul garis L. was studied after 24-h and 48-h treatment with different concentra tions of cadmium. The treatment of plants with 0.25 g(Cd2+) m(-3) caused di fferent changes in the chloroplasts of the two organs. The thylakoids swell ed in chloroplasts of leaf and the starch content increased in chloroplasts of traps. Higher concentrations of Cd (0.5 and 1.5 g m(-3)) caused osmioph ilisation of thylakoids in the chloroplasts of both studied organs. The sec retory cells in the trap wall was resistant to Cd.