Selenium (Se) is arguably one of the most interesting elements because it is both essential and toxic for most organisms, with a very narrow window between deficiency and toxicity compared with other trace elements (Schiavon & Pilon-Smits 2017). Selenium deficiency is considered the fourth most serious deficiency of minerals after iron (Fe), zinc (Zn), and iodine (I) (Boldrin et al. 2013). At present, Se biofortification in edible parts of crops may be an effective approach to reducing Se deficiency in the food chain (Zhou et al. 2018). Various countries have successfully implemented Se biofortification strategies, such as Finland (Broadley et al. 2007), the UK (Lyons 2010), and New Zealand (Curtin et al. 2006).