ABSTRACT
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. Selenate and selenite, two predominant forms of soil Se, have been successfully applied for crop Se bio-fortification in various crops. The uptake and accumulation of exogenous Se in crops is, however, different. Moreover, the bioavailability of Se to humans and animals largely depends on the speciation of Se in the edible parts rather than the total concentration of Se. Soil application of Se can reliably and effectively increase the Se content of wheat. At the same time, Se from soil application of selenite tended to accumulate in wheat root, while soil application of selenate was more efficient at increasing Se content in wheat grain.
