Selenium Biofortification and Interaction With Other Elements in Plants: A Review.

Xinbin Zhou,Jing Yang,Herbert J Kronzucker,Weiming Shi

doi:10.3389/fpls.2020.586421

Abstract

Selenium (Se) is an essential element for humans and animals and its deficiency in the diet is a global problem. Crop plants are the main source of Se for consumers. Therefore, there is much interest in understanding the factors that govern the accumulation and distribution of Se in the tissues of crop plants and the mechanisms of interaction of Se absorption and accumulation with other elements, especially with a view toward optimizing Se biofortification. An ideal crop for human consumption is rich in essential nutrient elements such as Se, while showing reduced accumulation of toxic elements in its edible parts. This review focuses on (a) summarizing the nutritional functions of Se and the current understanding of Se uptake by plant roots, translocation of Se from roots to shoots, and accumulation of Se in grains; and (b) discussing the influence of nitrogen (N), phosphorus (P), and sulfur (S) on the biofortification of Se. In addition, we discuss interactions of Se with major toxicant metals (Hg, As, and Cd) frequently present in soil. We highlight key challenges in the quest to improve Se biofortification, with a focus on both agronomic practice and human health.

Highlights

Se is an essential trace element for human and animal health, where it can be covalently incorporated into amino acids, selenocysteine (SeCys) and selenomethionine (SeMet), and acts as a cofactor for antioxidant enzymes such as glutathione peroxidase, and, in these chemical forms, is involved in the maintenance of the immune system, regulation of thyroid function, brain cognitive function, general antioxidant and detoxification capacity, and anti-cancer and anti-viral effects have been documented (Hatfield et al, 2014; Ullah et al, 2019)
In this review, we provide a summary of our current understanding of the mechanisms of Se uptake by plants, Se transport between root to shoot, within-plant Se distribution between organs and sequestration within edible parts, and of the principal interaction mechanisms with macronutrient elements and heavy metals, with an emphasis on the implications for Se biofortification and reductions in the toxic metal load of crop plants
We elucidate the nutritional effects of Se in plants and their consequences for crop consumption by humans, and summarize the basic mechanisms of uptake, long-distance transport, and biofortification of Se in grains

Summary

Introduction

Se is an essential trace element for human and animal health, where it can be covalently incorporated into amino acids, selenocysteine (SeCys) and selenomethionine (SeMet), and acts as a cofactor for antioxidant enzymes such as glutathione peroxidase, and, in these chemical forms, is involved in the maintenance of the immune system, regulation of thyroid function, brain cognitive function, general antioxidant and detoxification capacity, and anti-cancer and anti-viral effects have been documented (Hatfield et al, 2014; Ullah et al, 2019). Long-distance Se transport is important for regulating Se accumulation and increasing Se concentration in particular in crop-plant tissues that are most often consumed by livestock and by humans.

Results

Conclusion