LAUSR

Abstract Selenium (Se) is an essential micronutrient for animal and humans; however, its essentiality in plants is yet to be established. Nevertheless, its beneficial role is reported in crop plants particularly under biotic and abiotic stresses. Selenium adopts uptake/transport pathways in plants similar to that of sulfate and/or phosphates; it may replace sulfur at cellular level to synthesize important macromolecules including amino acids, specific structural and functional proteins and/ or potentially toxic non-specific proteins and other seleno-compounds. The toxic compounds and non-specific proteins may cause severe cellular toxicity either by altering structure and functions of important biomolecules (proteins, and enzymes) and/ or by producing reactive oxygen species (ROS) and reactive nitrogen species (RNS). Selenium deficiency in human beings may cause immune system disorders, impaired fertility, cardiovascular diseases, diabetes, inflammatory disorders and last but not the least many types of cancer. Keeping in view widespread deficiency of Se and associated health risks, it is necessary to adopt practices to improve Se content of human diet. Biofortification of Se in plants is one of the good strategies to combat occurrence of Se deficiency in humans while addressing the potential issues related to its economic viability and social acceptability. The current manuscript critically discusses the Se existence in the environment, essentiality for humans, uptake and translocation in plants, physiological toxicity mechanisms and beneficial role in plant cycle while biofortification strategies are also elaborated especially conventional approaches and recent modifications in Se enrichment of food crops. Moreover, it also emphasizes the issues regarding economics of Se biofortification and its social acceptance. Keeping in view the importance of Se for life, its human health consequences and economic feasibilities, appropriate biofortification strategies may serve better to eradicate its hidden hunger rather than its artificial supplementation.