Metal toxicity in plants is still a global problem for the environment, agriculture and ultimately human health. This review initially addresses the current state of the environmental/agricultural problem, and then discusses in detail the occurrence, mechanisms and relevance of toxicity of selected trace metals (Cd, Cu, Fe, Hg, Ni, and Zn). When discussing the mechanisms, special emphasis is laid on a critical review of their environmental/agricultural relevance, because even now many studies in this field of research are performed under highly artificial lab conditions. The main problems outlined in published studies are artificially high metal concentrations (which never occur even in highly polluted sites) combined with too short treatment times, as well as environmentally and agriculturally irrelevant growth conditions (e.g. constant light and submerged cultivation of seedlings). Furthermore, wherever possible an attempt is made to link the mechanisms published to date in terms of discussing which mechanisms are a direct cause of the observed disturbance of plant function and which are rather a consequence of the primary mechanisms, leading to a complicated toxicity phenotype and ultimately to diminished growth or even death of the plants.

Biology Center of the Czech Academy of Sciences Institute of Plant Molecular Biology Department of Plant Biophysics and Biochemistry Branišovská 31 1160 370 05 České Budějovice Czech Republic

Biology Center of the Czech Academy of Sciences Institute of Plant Molecular Biology Department of Plant Biophysics and Biochemistry Branišovská 31 1160 370 05 České Budějovice Czech Republic and University of South Bohemia Department of Experimental Plant Biology Branišovská 31 1160 370 05 České Budějovice Czech Republic

References provided by Crossref.org

Identification and characterization of transition metal-binding proteins and metabolites in the phloem sap of Brassica napus

Response of Three Miscanthus × giganteus Cultivars to Toxic Elements Stress: Part 1, Plant Defence Mechanisms

Analysis of trace metal distribution in plants with lab-based microscopic X-ray fluorescence imaging

Chronic exposure of soybean plants to nanomolar cadmium reveals specific additional high-affinity targets of cadmium toxicity

Analysis of OJIP Chlorophyll Fluorescence Kinetics and QA Reoxidation Kinetics by Direct Fast Imaging