Impact of IAA Application on Growth and Biochemical Aspects of Silybum marianum (L.) Gaertn. Under Lead Stress

In the present experiment, Indole-3-acetic acid (IAA)-mediated alleviation of lead (Pb) stress was investigated by analyzing the morphological, biochemical aspects and lead (Pb) metal uptake in Silybum marianum under Pb stress. Pb was applied in the form of lead acetate at concentration of 0.5 mM in the soil and IAA at 25, 50 and 100 ppm concentration. Pb stress significantly declined the S. marianum growth and biochemical aspects while application of IAA reversed this effect under Pb toxicity. IAA application also reduced the Pb uptake in which minimum Pb uptake of 12.10 µg g −1 was at 50 ppm under Pb stress after 60 DAS. It was concluded from the study that Pb stress can be mitigated successfully by the exogenous application of plant growth regulator, i.e., IAA.