Characterization of selenium-enriched wheat by agronomic biofortification

Abstract

Agronomic biofortification of staple crops is an effective way to enhance their contents in essential nutrients up the food chain, with a view to correcting for their deficiencies in animal or human status. Selenium (Se) is one such case, for its uneven distribution in the continental crust and, therefore, in agricultural lands easily translates into substantial variation in nutritional intakes. Cereals are far from being the main sources of Se on a content basis, but they are likely the major contributors to intake on a dietary basis. To assess their potential to assimilate and biotransform Se, bread and durum wheat were enriched with Se through foliar and soil addition at an equivalent field rate of 100 g of Se per hectare (ha), using sodium selenate and sodium selenite as Se-supplementation matrices, in actual field conditions throughout. Biotransformation of inorganic Se was evaluated by using HPLC−ICP-MS after enzymatic hydrolysis for Se-species extraction in the resulting mature wheat grains. Selenomethionine and Se VI were identified and quantified: the former was the predominant species, representing 70-100 % of the total Se in samples; the maximum amount of inorganic Se was below 5 %. These results were similar for both supplementation methods and for both wheat varieties. Judging from the present results, one can conclude that agronomic biofortification of wheat may improve the nutritional quality of wheat grains with significant amounts of selenomethionine, which is an attractive option for increasing the Se status in human diets through Se-enriched, wheat-based foodstuff.

Effects of a foliar spray of selenite or selenate at different growth stages on selenium distribution and quality of blueberries

“…Studies showed that foliar Se spray can increase the Se concentration in grain crops. For example, the Se concentration was approximately 2000 µg kg −1 in wheat grains after spraying foliar Se at 100 g ha −1 , 410 µg kg −1 in the rice grains after spraying foliar Se at 75 g ha −1 , and 1627–1827 µg kg −1 in the maize grains after spraying foliar Se at 200 g ha −1 . In the present study, the Se concentration of blueberry was only 44–114 µg kg −1 after spraying foliar Se spray at 200 g ha −1 and the Se‐enrichment ability of maize was approximately 14‐ to 42‐fold higher than that of the blueberry.…”

“…The low bioavailability of Se fertilizers applied to the soil is the result of some natural factors, such as soil type, redox condition, microbial activity and rainfall . Galinha et al . found that the Se concentration for foliar Se spray is two‐fold higher than that of soil Se application in wheat grains.…”

“…The low bioavailability of Se fertilizers applied to the soil is the result of some natural factors, such as soil type, redox condition, microbial activity and rainfall. [6][7][8] Galinha et al 9 found that the Se concentration for foliar Se spray is two-fold higher than that of soil Se application in wheat grains. Wang et al 8 reported that the Se recovery of maize seeds treated with foliar spray is approximately 31-to 112-fold higher than that treated with soil Se fertilization, with foliar Se spray usually having a higher bioavailability than soil application.…”

Genotypic Variation and Biofortification with Selenium in Brazilian Wheat Cultivars

“…Selenite and selenate are the inorganic forms of water‐soluble Se and are the most bioavailable forms of the element for plants (Dungan and Frankenberger, 1999). However, several studies have shown that selenate accumulates more in plant tissues than does selenite (Poblaciones et al, 2014; Galinha et al, 2015), due to the higher transportation rate of selenate through the xylem (Gupta and Gupta, 2017).…”

Sunflower seedlings hyperaccumulate Selenium

“…The awareness that the intake of Se by plants is the first step of Se entry into the human food chain could explain why biofortification with this element has received great attention. For instance, field treatments with Se or Se-rich compounds can be considered a safe, low-cost approach to achieving biofortification in Se-deficient areas [2,4,13,20,25,32,33].…”