Copper and cobalt accumulation in plants: a critical assessment of the current state of knowledge.
This review synthesizes contemporary understanding of copper-cobalt (Cu-Co) tolerance and accumulation in plants. Accumulation of foliar Cu and Co to > 300 μg g-1is exceptionally rare globally, and known principally from the Copperbelt of Central Africa. Cobalt accumulation is also observed in a limited number of nickel (Ni) hyperaccumulator plants occurring on ultramafic soils around the world. None of the putative Cu or Co hyperaccumulator plants appears to comply with the fundamental principle of hyperaccumulation, as foliar Cu-Co accumulation is strongly dose-dependent. Abnormally high plant tissue Cu concentrations occur only when plants are exposed to high soil Cu with a low root to shoot translocation factor. Most Cu-tolerant plants are Excluders sensu Baker and therefore setting nominal threshold values for Cu hyperaccumulation is not informative. Abnormal accumulation of Co occurs under similar circumstances in the Copperbelt of Central Africa as well as sporadically in Ni hyperaccumulator plants on ultramafic soils; however, Co-tolerant plants behave physiologically as Indicators sensu Baker. Practical application of Cu-Co accumulator plants in phytomining is limited due to their dose-dependent accumulation characteristics, although for Co field trials may be warranted on highly Co-contaminated mineral wastes because of its relatively high metal value.
Hydrogeochemistry and Soil-Environment Interactions (HydrISE), UP.2012.10.102, Institut Polytechnique LaSalle Beauvais, Beauvais, 60026, France.|Laboratory of Plant Ecology and Biogeochemistry, Université Libre de Bruxelles, Brussels, 1050, Belgium.
Bastien
B
Lange
Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, Qld, 4072, Australia.|Laboratoire Sols et Environnement, UMR 1120, Université de Lorraine - INRA, Vandoeuvre-les-Nancy, 54518, France.
Antony
A
van der Ent
Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, Qld, 4072, Australia.|Laboratoire Sols et Environnement, UMR 1120, Université de Lorraine - INRA, Vandoeuvre-les-Nancy, 54518, France.|School of BioSciences, The University of Melbourne, Parkville, Vic., 3010, Australia.
Alan John Martin
AJ
Baker
Laboratoire Sols et Environnement, UMR 1120, Université de Lorraine - INRA, Vandoeuvre-les-Nancy, 54518, France.
Guillaume
G
Echevarria
Department of Forest, Nature and Landscape, Biodiversity and Landscape Unit, Gembloux Agro-Bio Tech, University of Liège, Gembloux, 5030, Belgium.
Grégory
G
Mahy
Department of Forest, Nature and Landscape, Biodiversity and Landscape Unit, Gembloux Agro-Bio Tech, University of Liège, Gembloux, 5030, Belgium.
François
F
Malaisse
Laboratory of Plant Ecology and Biogeochemistry, Université Libre de Bruxelles, Brussels, 1050, Belgium.
Pierre
P
Meerts
Hydrogeochemistry and Soil-Environment Interactions (HydrISE), UP.2012.10.102, Institut Polytechnique LaSalle Beauvais, Beauvais, 60026, France.
Olivier
O
Pourret
Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, Brussels, 1050, Belgium.
Nathalie
N
Verbruggen
Hydrogeochemistry and Soil-Environment Interactions (HydrISE), UP.2012.10.102, Institut Polytechnique LaSalle Beauvais, Beauvais, 60026, France.
Michel-Pierre
MP
Faucon
D005075:Biological Evolution; D003035:Cobalt / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D013045:Species Specificity
D003035:Cobalt; D003300:Copper
accumulation; cobalt (Co); copper (Cu); hyperaccumulation; metal tolerance; metallophyte; phytomining; toxicity