Mechanisms to cope with arsenic or cadmium excess in plants.
The metalloid arsenic and the heavy metal cadmium have no demonstrated biological function in plants. Both elements are highly toxic and of major concern with respect to their accumulation in soils, in the food-chain or in drinking water. Arsenate is taken up by phosphate transporters and rapidly reduced to arsenite, As(III). In reducing environments, As(III) is taken up by aquaporin nodulin 26-like intrinsic proteins. Cd(2+) enters the root via essential metal uptake systems. As(III) and Cd(2+) share some similarity between their toxicology and sequestration machineries. Recent progress in understanding the mechanisms of As and Cd uptake and detoxification is presented, including the elucidation of why rice takes up so much arsenic from soil and of mechanisms of As and Cd hypertolerance.
Verbruggen
Nathalie
N
Laboratoire de Physiologie et de Génétique Moléculaire des Plantes, Faculté des Sciences, Université Libre de Bruxelles, Campus Plaine, Brussels, Belgium. nverbru@ulb.ac.be
Hermans
Christian
C
Schat
Henk
H
D001151:Arsenic / Q000378:metabolism* / Q000633:toxicity*; D001692:Biological Transport / Q000187:drug effects*; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008954:Models, Biological; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism*; D010944:Plants / Q000187:drug effects / Q000378:metabolism*; D012989:Soil Pollutants / Q000633:toxicity*
D012989:Soil Pollutants; D002104:Cadmium; D001151:Arsenic