Uptake of Cadmium byLemna minor, a (hyper?-) accumulator plant involved in phytoremediation applications

D Bianconi,M A Iannelli,F Pietrini,A Massacci,Nicola Pirrone

doi:10.1051/e3sconf/20130113002

Abstract

Metal pollution in waters and soils is a major environmental and human health problem. Cadmium (Cd 2+ ) is a heavy metal displaying toxic effects in plants. In this work we studied the potentiality of Lemna minor, a monocotyledonous aquatic macrophyte, to phytoremediate cadmium-polluted waters. The plants were exposed to different cadmium concentrations 0, 13, 22 and 46µM CdSO4 for a period of 24, 48 and 72 hours. Relative growth rates (RGR), bioconcentration factor (BCF), tolerance index (Ti), cadmium uptake in whole plant and maximum efficiency of PSII (Fv/Fm) were measured under controlled climate conditions. RGR, Ti and Fv/Fm declined with increasing exposure time and cadmium concentrations, while the BCF and cadmium uptake showed an opposite behavior. Data analysis of RGR, BCF, Ti and FV/FM indicates that L. minor maintains a good capacity of growth, metal bioconcentration, tolerance and efficiency of PSII up to 48h in plants exposed to 13 and 22µM CdSO4. Our results exhibited that L. minor is a good cadmium accumulator and is able to remediate Cd-polluted waters, especially at low Cd concentrations.

Highlights

Heavy metal pollution of soils and waters is a very serious environmental problem with potentially harmful consequences for agriculture and human health
Relative growth rates (RGR) of L. minor declined with increasing exposure time and Cd concentrations (Fig.1)
As reported in table 1, bioconcentration factor (BCF) of L. minor showed an increase in all tested Cd treatments and in response to time exposure

Summary

Introduction

Heavy metal pollution of soils and waters is a very serious environmental problem with potentially harmful consequences for agriculture and human health. Cadmium (Cd) was selected in this study since this metal ion, is toxic to living organisms and is a widespread, naturally occurring, element that is present in soils, rocks, waters, plants and animals. Lemna minor is a free-floating, aquatic perennial plant that forms a rapidly-expanding mat of foliage (to 1/4” tall) on water surface, able to remove and accumulate large amounts of cadmium, principally through the fronds (Zayed et al 1998). This study was carried out to evaluate the ability of Lemna minor to tolerate, remove and bioconcentrate cadmium in a short-term experiment

Methods

Results

Conclusion