Biochemical responses of Olea europaea L. cv. Chemlali exposed to air and soil pollution near the industrial complex in Sfax, Tunisia
Résumé
This study aims to evaluate the impact of complex air and soil pollutions on Olea europaea L. cv. chemlali, one of the most important commercially valuable crops in Tunisia. These field experiments were performed in the vicinity of the industrial complex in the South of Sfax, Tunisia for the polluted olive trees and in unpolluted areas for control ones. Several biomarkers were studied belonging mainly to the antioxidant system like enzymes or antioxidant compounds. Main results indicate that air and sol pollutions induced an oxidative stress as demonstrated by an increase in the rate of hydrogen-peroxide (H2O2) production, electrolyte leakage, and lipid peroxidation in all plant parts.
This stress affects chlorophyll and carotenoid contents of leaves. Additionally, the activities of enzymes involved in reactive-oxygenspecies (ROS) detoxification were affected. Air and soil pollutions induce an increase in the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD) and catalase (CAT). Moreover, in polluted olive trees, the content of antioxidant molecules like polyphenols, flavonoids and anthocyanins increases strongly. This is consistent with the role of these potent antioxidants in scavenging ROS such as H2O2. This study evidences the deleterious effects of industrial activity on antioxidative defense system of Olea europaea L. cv. Chemlali.