In a copper mine-tailing afforested we characterized the physicochemical properties of the substrate at vegetated and non-vegetated patches. We studied the accumulation of copper in roots and leaves of the species present at the site, to evaluate their phytoextraction and/or phytostabilization potential. The nonvegetated mine-tailing substrate showed a high content of metals, mainly copper (> 2.5 g kg-1), a pH 7.4, high content of salts and 5.0 % organic matter. Vegetated patches at the tailing showed similar characteristics of pH, salts and organic matter content, and showed a total copper concentration lower than the content found at the non-vegetated patches. Nine plant species present at the site were screened for copper accumulation and distribution in roots and leaves, and potential for copper phytoextraction or phytostabilization was suggested. The native species Schinus polygamus and Atriplex deserticola, accumulated over 1.2 g kg-1 copper in their leaves, showing that they are pseudometallophytes for the metal. Five of the nine plant species studied were considered suitable for phytoextraction procedures and four were apt for phytostabilization of copper polluted sites. By making a screening of species growing on a copper polluted site, we were able to select plants adapted to semi-arid environmental conditions and suitable for mine-tailings remediation purposes.

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Soil metal contamination associated with productive activities is a global issue. Metals are not biodegradable and tend to accumulate in soils, posing potential risks to surrounding ecosystems and human health. Plant-based techniques (phytotechnologies) for the in situ remediation of metal-polluted soils have been developed, but these have some limitations. Phytotechnologies are a group of technologies that take advantage of the ability of certain plants to remediate soil, water, and air resources to rehabilitate ecosystem services in managed landscapes. Regarding soil metal pollution, the main objectives are in situ stabilization (phytostabilization) and the removal of contaminants (phytoextraction). Genetic engineering strategies such as gene editing, stacking genes, and transformation, among others, may improve the phytoextraction potential of plants by enhancing their ability to accumulate and tolerate metals and metalloids. This review discusses proven strategies to enhance phytoextraction efficiency and future perspectives on phytotechnologies.

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