Antosiewicz Danuta Maria, Hennig Jacek
Department of Plant Morphogenesis, University of Warsaw, Institute of Plant Experimental Botany, Miecznikowa str 1, 02-096 Warszawa, Poland.
Environ Pollut. 2004 May;129(2):237-45. doi: 10.1016/j.envpol.2003.10.025.
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.
小麦cDNA LCT1是一种对Ca2+、Cd2+、Na+和K+的非特异性转运蛋白，在烟草中过表达。对转基因植株在一系列Ca2+浓度[0.01 - 10 mM Ca(NO3)2]下有无0.05 mM Cd(NO3)2存在时的敏感性进行了测试。还测定了钙和镉的积累情况。仅在低钙（0.01 - 1 mM Ca2+）条件下，LCT1转化植株表现出与对照不同的表型。它们生长得明显更好，地上部钙浓度略高。在1 mM Ca2+存在下接受0.05 mM Cd(NO3)2处理的转基因植株对镉表现出显著更高的耐受性，且根部积累的镉更少。这些结果首次证明LCT1参与钙的获取以及钙对镉毒性的缓解调节。
