Phytoremediative Potential of Tobacco under Deficit Irrigation Conditions for Ni-Polluted Soil

The aim of this study was to investigate the possibility of reclaiming Ni-polluted soils by phytoremediation under deficit irrigation conditions. Tobacco, Nicotiana rustica, was grown for 6 weeks at four different irrigation rates (100, 80, 60, and 40% of irrigation requirement) and four nickel concentrations (0, 50, 100, and 200 mg Ni.kg(-1) soil) applied from NiSO4. Nickel toxicity, water stress symptoms, dry shoot biomass, Ni concentration, and Ni uptake were followed. Neither Ni treatment nor water stress-induced Ni toxicity were observed, and there was no treatment-induced difference in chlorophyll content of leaves. With the increasing Ni application, there was a gradual increase in Ni concentration of the shoots from the 40% irrigation through 100% irrigation. As a result, the ability of tobacco to accumulate Ni at high concentration can enable it to be used for phytoremediation of Ni-polluted soils despite the fact that water deficit limits Ni accumulation to some extent.