Overexpression of LCT1 in tobacco enhances the protective action of calcium against cadmium toxicity.
Wheat cDNA LCT1, a nonspecific transporter for Ca2+, Cd2+, Na+ and K+, was overexpressed in tobacco. Transformants were tested for their sensitivity to a range of Ca2+-concentrations [0.01-10 mM Ca(NO3)2] with or without the presence of 0.05 mM Cd(NO3)2. Calcium and cadmium accumulation was also determined. LCT1-transformed plants expressed a phenotype distinct from controls only under conditions of low calcium (0.01-1 mM Ca2+). They grew significantly better and had slightly higher shoot calcium concentration. Transformants subjected to 0.05 mM Cd(NO3)2 in the presence of 1 mM Ca2+ displayed a substantially higher level of tolerance to cadmium and accumulated less Cd in roots. These results are the first to demonstrate the involvement of LCT1 in calcium acquisition and in the regulation of amelioration of Cd-toxicity by calcium.
Department of Plant Morphogenesis, University of Warsaw, Institute of Plant Experimental Botany, Miecznikowa str 1, 02-096 Warszawa, Poland. dma@biol.uw.edu.pl
Danuta Maria
DM
Antosiewicz
Jacek
J
Hennig
D002104:Cadmium / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins; D005786:Gene Expression Regulation; D005818:Genetic Engineering; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000235:genetics
D002352:Carrier Proteins; D027682:Cation Transport Proteins; C108683:LCT1 protein, Triticum aestivum; D010940:Plant Proteins; D012989:Soil Pollutants; D002104:Cadmium; D002118:Calcium