Uptake of yttrium, lanthanum and neodymium in Melastoma malabathricum and Dicranopteris linearis from Malaysia

Abstract

Plants that naturally accumulate aluminium (Al) may also inadvertently accumulate rare earth elements (REEs) due to the similar chemical properties of Al and REE trivalent ions, and vice versa. In this study, an Al hyperaccumulator plant species, Melastoma malabathricum, and a species known to have a propensity to hyperaccumulate REEs (in addition to Al), Dicranopteris linearis, were evaluated for potential REE accumulation in a one-year pot dosing trial in Sabah, Malaysia. To test whether the Malaysian accessions of D. linearis and M. malabathricum hyperaccumulate REEs (and Al), both species were grown in pots containing soil treated with solutions containing yttrium (Y), lanthanum (La), neodymium (Nd), and a mixture of these three REEs. The results showed that both M. malabathricum and D. linearis accumulated > 1000 µg g⁻¹ Al in their leaves as expected. The shoots of M. malabathricum contained lower REEs than the roots (50 µg g⁻¹ compared to 905 µg g⁻¹). In D. linearis, the mean foliar REE concentrations ranged from 145 to 315 µg g⁻¹, which is below the hyperaccumulation threshold set for REEs (> 1000 µg g⁻¹ REEs). This study revealed that the Malaysian accessions of both M. malabathricum and D. linearis are Al hyperaccumulators, but their REE hyperaccumulation status requires further testing.