Physiological responses to lead exposure in wheat, barley and oat

Lead (Pb) is an environmental pollutant extremely toxic to plants productivity and threatens human and animal health. Lead has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to lead exposure. To study the effects of lead on metabolism, four plant species, wheat (Triticum durum Desf and Triticum aestivum L.), barley (Ordeum vulgare L.) and oats (Avena sativa L.), were grown and stressed with lead acetate, Pb(CH3COO)2, at three concentrations (0.15, 0.3 and 0.6 g/l). The results indicate that lead stress affects all parameters measured. Treatment with 0.3 and 0.6 g/l of lead acetate showed an increase on total protein content in the leaves and roots of Triticum durum Desf. By contrast, the impacts of lead on soluble sugars differ between species; they are reduced in Triticum aestivum L and Ordeum vulgare L at all lead concentrations, whereas they are increased in Triticum durum Desf and Avena sativa L where their value peaks at 0.6 g/l Pb