Selenium (Se)uptake and transformation mechanisms and physiological function in plant: A review

Abstract

Selenium (Se) is an essential nutrient for many organisms, including microbe, animal and human, but the Se uptake and transformation mechanisms and physiological roles in plant still are controversial until now. Se could improve the growth and tolerance of plant at an appropriate le-vel, but could be toxic at higher levels. Research concerning Se uptake and metabolism in plant were promoted by Se biofortification and Se phytoremediation induced by the issues of Se deficiency in food and Se pollution in special areas. Recently, the results of Se uptake and transformation in plant have indicated that there are significant differences of Se accumulation and physiological roles in various plants and significant influence of soil conditions on Se uptake of plant. In addition, the process of Se metabolism in Se hyperaccumulators and its regulation were revealed gradually with the studies on improvement of Se uptake in plant. According to the results of Se biofortification in crop and Se phytoremediation so far, we summarized the advances in the studies with the reference to Se distribution in environment, the detail process of Se uptake, key regulators of transformation and its physiological roles in plant. We hope this can provide a novel insight to further research upon Se in plant.