Lead induced root and shoot growth reduction in wheat (Triticum aestivum L.) is due to increase in membrane lipid peroxidation

Lead (Pb) is one of the most phytotoxic metals in the agricultural soils and its concentration is continuously increasing mainly through anthropogenic activities. Present study was designed to investigate the phototoxic effects of lead (Pb) on different physiological parameter in Triticum aestivum L. Wheat seeds were germinated in petri plate at different concentration (0, 50, 100, 150, 200, 250 and 500μM) of Pb (NO3)2. The increasing lead concentration gradually and significantly decreased germination (%), fresh and dry weight, shoot and root length, decrease in chlorophyll and carotenoid content with respect to control. The hydrogen peroxide content and lipid peroxidation increased both in shoot and root, but those in root increased drastically over the control values. The peroxidative process in roots in Pb toxicity might be one of the major factors for inhibition of growth and pigment content in wheat seedlings.