Investigating the Effect of Lead on Marsilea minuta Linn. Under Hydroponic Conditions

The extent of Lead (Pb) concentration which causes toxicity in lower vascular plants, pteridophytes,
remains unclear. So the present study was aimed to investigate the extent of Pb accumulation with its
impact on physiological and biochemical basis of heavy metal tolerance in Marsilea minuta Linn. Lead
pollution is resulted from mining and smelting activities, Pb2+ containing paints, gasoline and
explosives as well as from disposal of municipal sewage sludge enriched in Pb and emission by motor
vehicles & industrial plants. Lead salt in lower concentrations (0 μM, 0.1 μM, 0.3 μM, 0.5 μM and 1.0
μM) was allowed to absorb by the plants for 12 days in hydroponic culture and a significant
deterioration of the plant biomass was recorded. However, roots absorbed more metals than the
leaves. Changes in leaf area, biomass allocation, chlorophyll content in leaf, total carbohydrate and
protein content were monitored. Higher concentrations upto 1.0 μM reduced biomass and chlorophyll
contents. A noticeable decrease in total protein content was noticed on early days of treatment
followed by a sharp increase in 0.3 μM, 0.5 μM and 1.0 μM treatments. Total carbohydrate content
were decreased, as compared to control condition, in 1.0 μM and increased in 0.5 μM treatment.