Alleviation of copper toxicity in germinating pea seeds by IAA, GA3, Ca and citric acid

The ameliorating effects of four exogenous effectors were investigated in germinating pea seeds exposed to copper excess. The results showed that the application of IAA, GA3, Ca or citric acid alleviated Cu-induced inhibition of growth and simultaneously reduced the oxidative stress injury, particularly contents of hydrogen peroxide, malondialdehyde and carbonyl groups. The improving effects can probably be mediated by the decreases in lipoperoxidation and protein oxidation as evidenced by changes in antioxidant enzyme activities. In addition, the efficiency of this recovery was compared within two types of treatments. Obtained results demonstrated that the stress abruption by the addition of effectors after three days of Cu application (treatment of type II) seems to be more effective than the simultaneous application of ‘Cu + effectors’ at the beginning of germination (treatment of type I). Data could provide some clues to physiological and biochemical mechanisms of the response of germinating seeds to the addition of chemicals under heavy metal stress