In this research we examined the effect of 0.25, 0.5 and 1 mM Pb(No3)2 with and without 0.5 mM EDTA in pH 4 and 6 on the growth and Pb accumulation in the root and shoot of four day old seedlings of Zea mays at the controlled condition in the period of 72 h. At the end of treatment we determined the length and dry weight of the root and Pb content in the root and shoot of the seedlings. In the second test we considered specially the effect of 0.25, 0.5, 1, 1.5 and 2 mM EDTA with 0.5 mM Pb(No3)2 on the seedlings of Zea mays at the same condition. After 72 h we determined the amount of Pb by Atomic Absorption and EDTA by HPLC and water content of shoot. We concluded (from the results of two tests) that: Pb absorption has grown up parallel to its concentration in growth solution and has inhibited root growth and biomass significantly. Pb taking up in pH 4 was higher than pH 6 and EDTA enhanced Pb accumulation in shoot. But water content of shoot decreased at the concentrations more than 0.5 mM EDTA in growth solution. Maximum level of EDTA accumulated in shoot of plants was at the concentration of 1.5 mM EDTA in the culture, but the highest level of Pb and the least water loss of shoot was at the equimolar Pb and EDTA (0.5 mM Pb with 0.5 mM ETDA). It may concluded that EDTA is taken up by plants, accumulated in shoots in the form of Pb-EDTA or protonated form and enhanced Pb accumulation in shoots of seedlings. So it can be used for phytoextraction of Pb and other metals not only by accumulators but also by tolerant plants such as Zea mays. But if EDTA is used for supplying plant micronutrients, its concentration should be minimized and its damage to plants should be clearly considered. PDFFulltextXMLReferencesCitation
How to cite this article
R. Heidari, M. Khayami and T. Farboodnia, 2005. Effect of pH and EDTA on Pb Accumulation in Zea mays Seedlings. Journal of Agronomy, 4: 49-54.