Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana)

Abstract

Lucky bamboo plants (Dracaena sanderiana) were used to study the accumulation and distribution of lead (Pb) in tissues of root, stem and leaf, as well as the impact of lead accumulation on the anatomical structure of these tissues. Dracaena sanderiana plants were exposed to Pb(NO3)2 solution at the Pb concentrations of 0; 200; 400; 600; 800; 1,000; 2,000; 3,000 and 4,000 mg/L for 60 days. The results showed that the more the Pb concentration was used, the more the amount of lead was accumulated and deposited. The tolerance limit of Dracaena sanderiana was 800 mg/L of Pb in water. The lethal concentration for plants was 4,000 mg/L Pb. When the concentrations of Pb in the solution were higher than the tolerance limit of the plant, the growth of Dracaena sanderiana could be inhibited. Dracaena sanderiana could accumulate up to 39,235 mg/kg Pb in the presence of Pb at 800 mg/L. Lead was accumulated mainly in roots (97.5%) and deposited mainly in the cell walls and the spaces between cells in tissues of roots. In the stems and leaves of Dracaena sanderiana, lead accumulation was limited and distributed mainly around vascular bundles. Lead accumulation caused changes in the anatomical structure of root, stem and leaf tissues. The accumulation and distribution of Pb is mainly in the cell walls and the space of cells; it could be a detoxification