Soil salinity improves the capacity of Atriplex nummularia Lindl. to phytoextract cadmium

The halophyte Atriplex nummularia Lindl. is commonly used for remediating salt-affected soils and can accumulate heavy metals, yet studies on metal phytoextraction in saline soils are limited. This study makes a significant contribution to advancing the existing knowledge by exploring how salinity influences the cadmium (Cd) phytoextraction mechanisms in Atriplex, providing new insights into the effects of salinity on the absorption, translocation, and accumulation of heavy metals in halophytic plants. This research evaluated salinity's effect on Cd phytoextraction by Atriplex. The experiment used saline (SL, EC = 14.23 dS m⁻¹) and non-saline (NSL, EC = 1.89 dS m⁻¹) Luvisols with six Cd levels (0-50 mg kg⁻¹). Parameters assessed included dry biomass of aerial parts (DBAp) and roots, Cd in aerial parts (CdAp) and roots, translocation factor (TF), water relations, ion concentrations, and gas exchange. Cd did not affect DBAp in NSL, showing tolerance, while in SL, DBAp exceeded NSL up to 34 mg kg⁻¹ . Gas exchange decreased with Cd, but water relations were unaffected. CdAp reached 49 and 25 mg kg⁻¹ in SL and NSL, respectively. Salinity provided a favorable TF up to the dose of 30 mg kg⁻¹ Cd. These results highlight the species' potential for Cd phytoextraction, especially in saline conditions.