Element Case Studies: Selenium

Authors: ZAMBRANO, MARIA CLEMENCIA - Madera Community College Center; YUAN, LINXI - Jiangsu University; YIN, XUEBIN - University Of Science And Technology Of China; Banuelos, Gary

Submitted to: Book Chapter
Publication Type: Literature Review
Publication Acceptance Date: 6/1/2020
Publication Date: 12/8/2020
Citation: Zambrano, M., Yuan, L., Yin, X., Banuelos, G.S. 2020. Element Case Studies: Selenium. In: van der Ent A., Baker A.J., Echevarria G., Simonnot MO., Morel J.L.(eds) Agromining: Farming for Metals. Mineral Resource Reviews. Springer, Cham. p. 393-413. https://doi.org/10.1007/978-3-030-58904-2_19.
DOI: https://doi.org/10.1007/978-3-030-58904-2_19

Interpretive Summary:

Technical Abstract: Metal-accumulating or metallophyte plants have become a major research focus in recent years. These plant species exert an enhanced capacity to extract metals from soil. Their innate tendency to tolerate and accumulate various elements in their shoots (hyperaccumulation), has opened unlimited possibilities to explore, and to apply new plant-based technologies, e.g., phytoremediation, for potentially cleaning metal-laden soils Similarly, the concept of ¨phytomining¨ is a nascent green technology that will apply hyperaccumulator plants to degraded soils for extracting metals, which can be harvested, dried and incinerated to collect bio-ore. Some hyperaccumulators also can accumulate metalloids like selenium (Se), which can be indirectly incorporated into the food web chain through agriculture activities and generate Se-enriched products of economic value. In this regard, hyperaccumulators can also be used for Se biofortification strategies for increasing Se intake into animals and humans. Such Se-hyperaccumulators like Stanleya pinnata (Prince plume). Astragalus bisulcatus (two-grooved milkvetch) and the newly discovered Se-hyperaccumulator Cardamine hupingshanensis (bittercress) from China. These three plant species are suggested for use in agromining of high Se soils due to their ability to extract excessive amounts of Se from soil without exhibiting symptoms of toxicity. Several studies have shown that primary Se-hyperaccumulators accumulate between 2,000 to 5,000 mg Se kg/ DW on seleniferous soils (2 to 10 mg Se/kg) without suffering toxicity, while two-grooved mikvetch can accumulate up to 12,500 mg Se/kg DW. Due to their high Se concentrations in their tissues, Se-hyperaccumulators are more pest tolerant and deter herbivory attacks when planted alone or with food crops, and they can be effectively used as Se-biofertilizers. Assuming high Se soils are available, e.g., westside of the San Joaquin Valley, selecting, growing and utilizing a Se-hyperaccumulator species can be part of an agronomic activity to provide growers in Se-regions with an additional strategy for producing Se-biofertilizer for Se biofortification strategies.