A recent study by Dr. Alicja Babst-Kostecka, University of Arizona Superfund Research Center (UA SRC) Co-Investigator for Project 5, looks at how some hyperaccumulating plants – plants that collect a high volume of metals– can remediate metal-contaminated sites and potentially provide a sustainable alternative to industrial approaches.
To better anticipate the outcome of phytoremediation efforts, the team of investigators for this study evaluated the potential for soil metal-bioavailability to predict trace metal elements (TME) accumulation in two non-metallicolous and two metallicolous populations of the Zinc (Zn) and Cadmium (Cd) hyperaccumulator Arabidopsis halleri. Metallicolous plants have adapted to grow preferentially in soils containing a higher-than-normal concentration of a particular metal.
The team also examined the relationship between a population's habitat and its efficiency to remove contaminants from soils, or the phytoextraction efficiency. Total Zn and Cd concentrations were quantified in both soil and plant material, and bioavailable fractions in soil were quantified via Diffusive Gradients in Thin-films (DGT).
The study found that shoot TME accumulation varied independent from both total and bioavailable soil TME concentrations in metallicolous individuals. In fact, hyperaccumulation patterns appear more driven by the plant itself and less driven by soil. One non-metallicolous population proved to be as efficient in accumulating Zn on non-polluted soil as the metallicolous populations in their highly contaminated environment.
These findings demonstrate that information from original sample or growth sites on plant phytoextraction efficiency is indispensable to optimize site-specific phytoremediation measures. If successful, hyperaccumulating plant biomass may be valuable source material for application in the emerging field of green chemistry.
Dietrich CC, Tandy S, Murawska-Wlodarczyk K, Banas A, Korzeniak U, Seget B, Babst-Kostecka A. 2021. Phytoextraction efficiency of Arabidopsis halleri is driven by the plant and not by soil metal concentration. Chemosphere 285, 131437. https://doi.org/10.1016/j.chemosphere.2021.131437