Intranuclear complexes in a copper-tolerant green alga.

Abstract

The results of ultrastructural studies and transmission electron microscope microanalysis of two Scenedesmus strains experimentally exposed to copper sulfate are presented. A fine-structural examination of the cells revealed the presence of nuclear inclusions in the form of central dense-core complexes. Cytoplasmic structures resembling the intranuclear inclusions were occasionally found in the cells. TEM-X-ray microanalysis of these structures has provided evidence that the inclusions contain copper. It is concluded that their presence may be regarded as a detoxifying mechanism.

Algal Toxicity Tests for Environmental Risk Assessments of Metals

“…Although it is sometimes difficult to distinguish between the two phenomena, there is an increasing body of evidence for rapid genetic evolution resulting from a variety of anthropogenic stresses. Metal tolerance in algae has been described by Butler et al (1980), Chapman (1985, Fitzgerald and Faust (1963), Klerks and Weis (1987), Silverberg et al (1976), Stockner and Antia (1976), and Stokes and Dreier (1981). Soldo and Behra (2000) exposed a natural periphyton population from the river Glatt (Switzerland) during 16 wk to various Cu concentrations (ranging from 0.05 to 5 µM) and observed an increased Cu tolerance in populations previously exposed to Cu.…”

Microalgae – A promising tool for heavy metal remediation

“…Subsequent to chronic exposure to Cu, C. vulgaris are known to have developed tolerance, thereby, showing an increased ability to prevent Cu enrichment (Lindestrom, 1980). Silverberg et al (1976) reported Scenedesmus spp. grown in media containing 1 mg l À 1 copper to become copper-tolerant, wherein they contained 0.76 mg Cu g À 1 dry weight; these authors also reported that the non-tolerant Scenedesmus spp.…”

Toxicity and Tolerance in the Responses of Plants to Metals

“…The Cu-rich complexes identified within the nuclei of Cu-tolerant strains of the green algae Scenedesmus (SILVERBERG et al 1976) may also be proteins of the metallothionein type. Cd-binding proteins have been isolated from Anacystis nidulans (MACLEAN et al 1972), soybean (CASTERLINE andBARNETT 1977), tomato (BARTOLF et al 1980), and Phaseolus vulgaris (WEIGEL and JAGER 1980).…”