Effects of copper, nickel and zinc on biochemical parameters and metal accumulation in gouan, Aeluropus littoralis

摘要

To study the effects of three heavy metals (Cu, Zn and Ni) on Aeluropus littoralis, a halophytic plant, a research was carried out in greenhouse. The study was laid out in a randomized complete block design with 5 replicates. Two different concentrations (50 μM and 100 μM) for each metal were used. Some cellular oxidative biomarkers such as activity of three main antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPx) and catalase (CAT)), as well as accumulation of proline, phenolic compounds, photosynthetic pigments and soluble protein content were investigated. The results showed that the proline and phenolic compounds accumulated with increasing heavy metal concentrations, while total chlorophyll content decreased in all treatments. Heavy metals contents in shoots increased with the increasing of heavy metals concentration without any important morphological changes. In all treatments SOD activity increased, but GPx activity decreased while CAT activity and soluble protein only decreased in Ni and Cu treatments, respectively. The results showed that chlorophyll a was more sensitive to Zn and Ni, but chlorophyll b was more sensitive to Cu. In addition, it was revealed that each heavy metal has unique biotoxicities or biofunctions and affects the analyzed parameters plant in particular way. Consequently, A. littoralis heavy metal tolerance depends on the species and concentration of metal.