**1. Introduction**

Heavy metal pollution of soil and water is a worldwide concern because of its harmful effect on human health. The constant accumulation of heavy metals in soil can pose a serious risk to living organisms including plants, animals, and microorganisms [1, 2]. To date, phytoremediation is confirmed to be the most environmentally friendly and cost-effective strategy. Types of phytoremediation include phytoextraction, phytovolatilization, phytostabilization, phytodegradation, and rhizosphere. The advantages of phytoremediation compared with traditional physical surface and chemical remediation methods are low cost and simplicity [3]. Phytoremediation is linked with the morphological, biochemical, and physiological effects on plant growth. During the phytoremediation process, some morphophysiological growth parameters have to be evaluated such as root growth, net biomass weight, leaf area, the net rate of photosynthesis, the effects on the plasma membrane of plants, reactive oxygen species (ROS) generation, hydrogen peroxide (H2O2) content, and malondialdehyde (MDA) level, linked to genotoxicity. Plants try to elude

their harmful effects by adopting various defense mechanisms, which include antioxidant activation and other mechanisms of metal homeostasis. In response, plants have developed enzymatic and nonenzymatic antioxidant mechanisms and increased activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD) [4].

In literature, *C. indica* was investigated by different authors as phytoremediation species in pot, hydroponic, and wetlands systems [5–7]. Most of these works focused on the efficiency of the plant to accumulate heavy metals but did not evaluate the effect of these metals on the physiology of the plant.

This study aimed to evaluate the impact of Zn(II) and Cu(II) excess on the growth and metabolism of *C. indica* through the determination of physiological parameters and Zn(II) and Cu(II) bioaccumulation to establish the strategies used by the plant to overcome the stress and determine the correlation between metal accumulation and physiological parameters modification. Results obtained were compared with parameters measured and published in the scientific literature to provide information for future phytoremediation research.
