Evaluation of Toxic Effect of Copper and Cadmium on Growth, Physiological Traits and Protein Profile of Wheat

A pot experiment was carried out in order to investigate the effect of deleterious concentration of copper and cadmium either individual or in combination on three cereal crops i.e. wheat (Triticum aestivum L.), maize (Zea mays L.) and sorghum (Sorghum bicolor L.) after 2 and 4 weeks. The results showed that cadmium applied alone caused significant reduction in growth traits and photosynthesis (P< 0.05 or P <0.01). The effect was less pronounced when Cu applied alone or in combination with Cd . The same trends were also observed +2 with leaf osmotic potential and relative water content under the same treatments. The stress associated protein, profiles in leaves at 14 kDa in wheat, 35 and 54 kDa in maize were disappeared, compared to others treatments, in response to 75 Cu, 150 Cu, 75 Cd , 150 Cd and 150 Cd , 75 Cu +75 Cd μmol/L after four weeks, +2 +2 +2 +2 respectively. A 60 and 16 kDa a soluble protein was over expressed only in sorghum under 150 Cd μmol/L and +2 in wheat under 150 Cd μmol/L and 75 Cu + Cd μmol/L. These proteins designated as cadmium stress +2 + +2 inducible protein (CSIP) and may be appositive marker to cadmium stress tolerance in sorghum and wheat. It could be concluded that, in all three crops, the effect of different treatments were more toxic in order to Cd < Cu + Cd < Cu < control either after 2 or 4 weeks. Also, sorghum was more tolerance to heavy metal stress + +2 followed by wheat and maize; and it could help alleviate crop losses in area affected by heavy metals stress.