title: Development of a multi-species biotic ligand model predicting the toxicity of trivalent chromium to barley root elongation in solution culture.
abstract: Little knowledge is available about the influence of cation competition and metal speciation on trivalent chromium (Cr(III)) toxicity. In the present study, the effects of pH and selected cations on the toxicity of trivalent chromium (Cr(III)) to barley (Hordeum vulgare) root elongation were investigated to develop an appropriate biotic ligand model (BLM). Results showed that the toxicity of Cr(III) decreased with increasing activity of Ca(2+) and Mg(2+) but not with K(+) and Na(+). The effect of pH on Cr(III) toxicity to barley root elongation could be explained by H(+) competition with Cr(3+) bound to a biotic ligand (BL) as well as by the concomitant toxicity of CrOH(2+) in solution culture. Stability constants were obtained for the binding of Cr(3+), CrOH(2+), Ca(2+), Mg(2+) and H(+) with binding ligand: log KCrBL 7.34, log KCrOHBL 5.35, log KCaBL 2.64, log KMgBL 2.98, and log KHBL 4.74. On the basis of those estimated parameters, a BLM was successfully developed to predict Cr(III) toxicity to barley root elongation as a function of solution characteristics.
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Song
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhong
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China; Institute of Plant Nutrition and Environmental Resources, Liaoning Academy of Agricultural Sciences, Shenyang, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Jumei
authors.initials: J
authors.lastname: Li
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Dongpu
authors.initials: D
authors.lastname: Wei
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ma
mesh_terms: D002118:Calcium / Q000378:metabolism; D002412:Cations / Q000378:metabolism; D002857:Chromium / Q000633:toxicity*; D001467:Hordeum / Q000187:drug effects* / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008274:Magnesium / Q000378:metabolism; D008954:Models, Biological; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D002412:Cations; D008024:Ligands; D012989:Soil Pollutants; D002857:Chromium; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium