Effects of lead, EDTA, and IAA on nutrient uptake by alfalfa plants
Journal of Plant Nutrition
The element concentrations of alfalfa plants exposed for 10 d to 40 mg lead (Pb) L- 1 from lead nitrate [Pb(NO3)2] alone, or combined with ethylenediaminetetraacetic acid (EDTA) and indole-3-acetic acid (IAA), was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Indole-3-acetic acid at 10 μM and Pb/EDTA/IAA at 10 μM increased potassium (K) concentration in roots by 87% and 94%, respectively (P < 0.05). However, IAA at 100 μM decreased K concentration in leaves (P < 0.05). Plants exposed to 100 μM IAA, Pb/IAA at 100 μM, and Pb/EDTA/IAA at 100 μM had, respectively, 30%, 55%, and 40% more sulfur (S) in leaves than control plants (P < 0.05). Lead and Pb/IAA reduced Ca concentration in stems and leaves (P < 0.05). Conversely, Pb and Pb/EDTA increased Cu concentration in roots and stems. IAA at 100 μM, Pb, and Pb/EDTA/IAA decreased Zn concentration in roots (P < 0.05). Manganese (Mn) and molybdenum (Mo) concentration in roots and stems was lower in plants treated with Pb and Pb/IAA (P < 0.05). Pb and Pb/IAA reduced (P < 0.05) the iron (Fe) concentration in roots. However, the addition of EDTA and IAA at 10 μM reduced the negative effects of Pb on Fe absorption. Copyright © Taylor & Francis Group, LLC.