Effects of Selenium on Plant Metabolism and Implications for Crops and Consumers

Abstract

Selenium (Se) is an essential trace element for many organisms including humans, while in plants it can trigger a variety of beneficial effects. Plants absorb Se mainly in the form of selenate using high affinity root sulfate transporters. Consequently, availability of sulfur (S) has a major impact on Se accumulation due to competition effects of the two oxyanions. In addition, Se has an impact on S uptake through interference with intrinsic regulatory mechanisms. Inside cells, selenate can access the sulfate assimilation pathway and influence the production of S-organic compounds that are of vital importance in plant responses to biotic and abiotic stress conditions. Selenium has been reported to mitigate stress in plants because of its capacity to induce the synthesis of S-and nitrogen (N) compounds, in addition to stimulating the activity of antioxidant enzymes and metabolites. Selenium can also alter the uptake of certain microelements like molybdenum, which functions as a cofactor for the enzyme nitrate reductase. Therefore, Se at high doses may interfere with N assimilation, causing a decrease in the level of N-compounds with structural and/or regulatory functions. Selenium interactions with multiple metabolic pathways in plants have relevant implications for plants and consumers that feed on them. Managing such interactions are useful to biofortify crops with organic forms of Se endowed with beneficial properties (selenomethionine and methylselenocysteine) and in other nutraceuticals like glucosinolates and antioxidants. Furthermore, Se at low doses may improve plant productivity or

On the Ecology of Selenium Accumulation in Plants

“…However, it cannot be excluded that Se additionally upregulates the production of other defense compounds. The interaction between Se and (other) defense compounds is an area that is relatively under-studied [34].…”

Potato Growth and Yield Attributes as Affected by Boron and Selenium Foliar Application

“…On potato, the Br and Se application has been reported to positively influence photosynthesis (Turakainen et al, 2004). The positive effects of Se concentrations on the photosynthetic process may be explained via the improvement of the cell antioxidant activity at different levels (Schiavon et al, 2017). Table 6.…”

Selenium Biofortification Differentially Affects Sulfur Metabolism and Accumulation of Phytochemicals in Two Rocket Species (Eruca Sativa Mill. and Diplotaxis Tenuifolia) Grown in Hydroponics

“…Selenium fertilization may alter the synthesis of additional metabolites with recognized nutritional properties, like phenolic acids and amino acids [37,39,40], which are particularly abundant in cruciferous vegetables. Both phenolics and amino acids are N-compounds and Se may affect N metabolism via either interaction with the S pathway and/or reduction of molybdenum (Mo) uptake, Mo being an indispensable cofactor for the activity of nitrate reductase [37,40].…”