Potential of halophytic plant Atriplex hortensis for phytoremediation of metal-contaminated soils in the mine of Tamra

ABSTRACT

Contamination by metals from anthropogenic activities has significant consequences for ecosystems and human health. Indeed, these elements, by nature are non-biodegradable, have a high ecotoxicity, and could be involved in many pathologies. The genus Atriplex is well adapted to extreme environmental conditions and exhibits heavy metal accumulation properties. This study aimed to examine the response of halophytic plant (Atriplex hortensis) in soil polluted with toxic elements. To address this, we measured plant growth parameters, chlorophyll fluorescence parameters of optimal (Fv/Fm), PSII quantum yield (ϕPSII), and stomatal conductance (g_S). By applying this metallic stress to the A. hortensis plant during 2 months of growth, morphological analyses show no reduction in the leaf area, elongation of the stems and roots, and dry matter compared to controls grown on sand. Biochemical and physiological analyses show a slight decrease in the content of foliar chlorophyll pigments (chlorophyll total) and carotenoids as a function of time in soil contaminated with heavy metals. In these experiments, we investigated the photosynthetic rate and chlorophyll fluorescence parameters; the results indicated that on polluted and sandy soil, the values of chlorophyll fluorescence parameters of optimal (Fv/Fm), effective quantum yield of photosystem II photochemistry (ϕPSII) and stomatal conductance (g_S) have no significant difference. The results obtained in our study show that A. hortensis can grow in environments heavily polluted by metals, such as zinc, lead, and cadmium. As a result, the cultivation of these species, often recommended for the phytostabilization of sites polluted by metals, could be established. The results obtained are in favor of the involvement of Atriplex hortensis in a phytoremediation project to clean up contaminated soils.

KEYWORDS:

• Heavy metals
• atriplex hortensis
• morphological parameters
• physiological parameters
• chlorophyll fluorescence

Acknowledgments

The authors would like to thank the anonymous reviewer for checking the manuscript.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

CRediT authorship contribution statement

S. Sai Kachout: Conceptualization, Data curation, Writing – original draft, Writing-Review and Editing, Figures, Supervision, Project coordinator. A. Ennajah and A. Zoghlami: Conceptualization, Data curation, Writing-Original draft preparation, Writing-Review, and Editing, Tables. ORCID: https://orcid.org/0000–0002–8519–3432

Additional information

Funding

This work was funded by the Ministry of Higher Education and Scientific Research (MHES), Tunisia; as part of the project of encouragement of young researchers (20PEJC 01-16).