Abstract

Plants of Lessonia trabeculata and L. nigrescens were studied by transmission electron microscopy in order to evaluate ultrastructural level changes in response to copper exposure. Samples of fronds, stipes, and holdfasts were collected from areas with and without copper mining discharges. Changes in cell ultrastructure observed in Lessonia trabeculata were related to copper concentrations in seawater, seaweeds and extracted alginates. The results strongly suggest that tolerance or adaptation of Lessonia to high concentrations of copper is the capacity of different plant tissues to accumulate copper as precipitates, primarily at two levels: the cell wall and periplasmalemmal space, with the vacuolar system being a third site.