Armeria maritima from a calamine heap -: Initial studies on physiologic-metabolic adaptations to metal-enriched soil

Plants of Armeria maritima are found both on unpolluted sites and on soils strongly polluted with heavy metals. Seedlings of A. maritima from a zinc-lead calamine heap in ore-mining region (Boleslaw population) and from unpolluted area (Manasterz population) were tested to determine the zinc, cadmium and lead tolerance. In hydroponic experiments Boleslaw population was more tolerant to zinc, cadmium and lead. Localization of heavy metals in roots was determined using the histochemical method for detecting metal-complexes with dithizone. Their accumulation was found in root hairs, rhizoderma and at the surface of the central cylinder. Glutathione level in plants increased after metal treatment of both populations. However, its high level was not correlated with phytochelatin production. These metal-binding complexes were not detected in plants exposed to zinc, cadmium or lead. Changes of organic acids concentrations in Armeria treated with metals may suggest their role in metal translocation from roots to shoots. The content of organic acids, especially malate, decreased in the roots and increased in the leaves. These changes may be important in Pb-tolerance of Manasterz: population and in Zn-, Cd-tolerance of calamine population from Boleslaw. (c) 2007 Elsevier Inc. All rights reserved.