, Mohd Israr, and Shivendra Sahi. Department of Biology, Western Kentucky University, 1906 College Heights Blvd# 11080, Bowling Green, KY 42101
Experiments were conducted to study the effect of indole-3-acetic acid (IAA), naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and ethylene diamine tetraacetic acid (EDTA) on growth, photosynthesis, and lead (Pb) uptake in
Sesbania drummondii seedlings.
S. drummondii seedlings were grown for 10 days in Pb(500 mgl-1) and EDTA (200然) and different concentrations (1, 10, and 100 然) of IAA, NAA, and 2,4-D. Seedling growth was not significantly affected with EDTA and hormonal treatments (except 2,4-D)when compared with the seedlings grown in Pb alone. However, higher concentration (100 然) of 2,4-D was toxic to plants. Photosynthetic activity was assessed by measuring chlorophyll a fluorescence by determination of Fv/Fm and Fv/Fo values. Similar to growth, photosynthetic integrity was not affected with EDTA and hormonal treatments. However, photosynthetic integrity was drastically affected at 100 然 of 2,4-D. Pb accumulation in Sesbania shoots were significantly influenced with EDTA and hormonal treatments. The accumulation of Pb in Sesbania shoots increased with increasing growth hormones concentration in the medium. Among hormones, IAA and NAA (with EDTA) at 10 and 100 然 concentration accumulated maximum amount of Pb in shoots. The results of the present study suggest that the uptake of Pb in Sesbania shoots are influenced by growth hormones in presence of EDTA.