Biofortification and phytoremediation of selenium in China

Authors: WU, ZHILIN - Anhui Agricultural University; Banuelos, Gary; LIN, ZHIQING - Southern Illinois University; YIN, XUEBIN - Suzhou Institute For Advanced Study, Ustc; YUAN, LINXI - Suzhou Institute For Advanced Study, Ustc; LIU, YING - Suzhou Institute For Advanced Study, Ustc; LI, MIAO - Suzhou Institute For Advanced Study, Ustc

Submitted to: Frontiers in Plant Science
Publication Type: Literature Review
Publication Acceptance Date: 4/1/2015
Publication Date: 5/1/2015
Citation: Wu, Z., Banuelos, G.S., Lin, Z., Yin, X., Yuan, L., Liu, Y., Li, M. 2015. Biofortification and phytoremediation of selenium in China. Frontiers in Plant Science. 3:4-6. doi: 10.3389/fpls.2015.00136.

Interpretive Summary: Selenium (Se) is an essential trace element for humans and animals but at higher concentrations Se can become toxic to organisms. In Se-deficient regions of the world, Se biofortification is an important agricultural process that increases the accumulation of Se in crops through plant breeding, genetic engineering, or use of Se fertilizers. In soils with excessive Se, phytoremediation is a green biotechnology used to clean up the Se-laden environment. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation sites can be used as Se-enriched green manures or as supplementary sources of Se fertilizer for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se were based on natural variation or identification of unique plant species to accumulate Se. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops, genetic engineering, microbial inoculation, and biotechnology. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se are highlighted, and the future development and uses of Se-biofortified agricultural products in China have are discussed.

Technical Abstract: Biofortification is an agricultural process that increases the uptake and accumulation of specific nutrients, e.g. selenium (Se), in agricultural food products through plant breeding, genetic engineering, and manipulation of agronomic practices. The development and uses of biofortified agricultural products have been proposed as a promising functional agricultural strategy to increase the dietary nutrient intake of Se for humans. Phytoremediation of Se is the use of plants and their associated microbes for environmental cleanup, through processes that include phytoextraction, rhizofiltration, and phytovolatilization. Water and soil Se contamination resulting from coal production activities and agricultural drainage produced from irrigated Se-laden soils have caused significant toxic impacts on aquatic wildlife, such as deformity of waterfowl as observed at the Kesterson National Wildlife Refuge in central California. Phytoremediation is an alternative and sustainable remediation plant-based technology compared with traditional physical and chemical remediation approaches. Both Se phytoextraction and biofortification processes are based on bioaccumulation of Se that involves plant uptake, distribution, accumulation, and transformation of Se absorbed from soil into the plant’s matrix. Although the goals of biofortification and phytoremediation of Se are different, these two processes can sometimes be closely connected on enhancing the efficiency of Se uptake and accumulation in plants. Therefore, it is important to better understand the rhizosphere and physical, chemical, and biological processes that affect soil Se bioavailability, plant uptake, distribution, and transformation of Se in the plant. Optimizing these critical processes will help to determine the success of biofortification and phytoremediation of Se. In this review, we will focus on Se and use this nutrient as an example to demonstrate the processes of biofortification and phytoremediation as a combined emerging concept for addressing the environmental and human health concerns associated with both insufficient or excessive Se.