The present study aimed to explore the tolerance potential of Cd, Pb and Cu and physiological alterations in two common tree species growing in Minia governorate (Egypt) namely: Eucalyptus globulus and Ficus nitida and to investigate the leaf features [leaf area (LA) and specific leaf area (SLA)] associated with the phytoremediation process. The findings may be useful for future surveillance as preliminary reference values for levels of heavy metals in urban and industrial settings. The levels of cadmium, lead and Cupper in plant leaf were determined. The results showed that heavy metals could inhibit the growth of plants including LA and SLA. The water content (WC) and photosynthetic pigments of Eucalyptus and Ficus decreased with the increased concentration of metals. Contrary to chlorophylls (a) and (b), carotenoids and chlorophyll ratio (a/b) showed a significant increase with increasing metals concentration especially that of Cd and Cu. Proline content was relatively increased and soluble carbohydrate content decreased in plants with high metal accumulation. Eucalyptus showed better tolerance capacity for Cd, Pb and Cu when compared to Ficus. The ability of Eucalyptus to accumulate and tolerate metal stress makes this species a good candidate to recuperate heavy metals-contaminated conditions.
Keywords: Heavy metal; hyperaccumulator; leaf surface morphology; physiological response; phytoremediation.