Mutielemental concentration and physiological responses of Lavandula pedunculata growing in soils developed on different mine wastes

This study aimed to: i) evaluate the accumulation and translocation patterns of potentially hazardous elements into the Lavandula pedunculata and their influence in the concentrations of nutrients; and ii) compare some physiological responses associated with oxidative stress (concentration of chlorophylls (Chla, Chlb and total), carotenoids, and total protein) and several components involved in tolerance mechanisms (concentrations of praline and acid-soluble thiols and total/specific activity of catalase (CAT) and superoxide dismutase (SOD)), in plants growing in soils with a multielemental contamination and non-contaminated. Composite samples of soils, developed on mine wastes and/or host rocks, and L. pedunculata (roots and shoots) were collected in Sao Domingos mine (SE of Portugal) and in a reference area with non-contaminated soils, Corte do Pinto, with the same climatic conditions. Sao Domingos soils had high total concentrations of several hazardous elements (e.g. As and Pb) but their available fractions were small (mainly <5.8 % of the total). Translocation behaviour of elements was not clear according to the physiological importance of the elements. In general, plant shoots from Sao Domingos had the highest elements concentrations, but only As, Mn and Zn reached phytotoxic concentrations. Concentration of Chlb in shoots from Sao Domingos was higher than those from Corte do Pinto. No significant differences were obtained between concentrations of Chla, total protein, praline and acid-soluble thiols in shoots collected in both areas, as well as SOD activity (total and specific) and specific CAT activity. Total CAT activity varied with population being lower in the shoots of the plants from Sao Domingos, but no correlation was obtained between this enzymatic activity and the concentrations of the studied elements in shoots. Lavandula pedunculata plants are able to survive in soils developed on different mine wastes with multielemental contamination and low fertility showing no symptoms (visible and physiological) of phytotoxicity or deficiency. (C) 2016 Elsevier Ltd. All rights reserved.