Lock Koen, Van Eeckhout Hilde, De Schamphelaere Karel A C, Criel Peggy, Janssen Colin R
Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, 9000 Gent, Belgium.
Chemosphere. 2007 Jan;66(7):1346-52. doi: 10.1016/j.chemosphere.2006.07.008. Epub 2006 Sep 5.
A biotic ligand model (BLM) was developed to predict nickel toxicity, affecting root growth of barley (Hordeum vulgare), in nutrient solutions. The extent to which Ca(2+), Mg(2+), Na(+), K(+) ions and pH each influenced nickel toxicity was determined. Higher activities of Mg(2+) linearly increased the 4d EC50 Ni (2+) , while Ca(2+), Na(+), K(+) and H(+) activities did not significantly influence Ni(2+) toxicity. Stability constants for the binding of Ni(2+) and Mg(2+) to the biotic ligand were obtained: logK(NiBL)=5.27 and logK(MgBL)=3.47. Further, it was calculated that on average 57% of the biotic ligand sites needed to be occupied by nickel to induce 50% root growth inhibition. Auto-validation of the BLM indicated that predicted EC50s differed from the observed EC50s by a factor of less than 2, indicating that the BLM concept may also be used to predict metal toxicity to terrestrial plants.
开发了一种生物配体模型（BLM）来预测镍对营养液中大麦（Hordeum vulgare）根系生长的毒性。确定了Ca(2+)、Mg(2+)、Na(+)、K(+)离子和pH各自对镍毒性的影响程度。Mg(2+)的较高活性使4天EC50 Ni(2+)线性增加，而Ca(2+)、Na(+)、K(+)和H(+)的活性对Ni(2+)毒性没有显著影响。获得了Ni(2+)和Mg(2+)与生物配体结合的稳定常数：logK(NiBL)=5.27和logK(MgBL)=3.47。此外，经计算，平均57%的生物配体位点需要被镍占据才能诱导50%的根系生长抑制。BLM的自动验证表明，预测的EC50与观察到的EC50相差不到2倍，这表明BLM概念也可用于预测金属对陆生植物的毒性。
