Influence of Selenium on Growth, Physiology, and Antioxidant Responses in Maize Varies in a Dose-Dependent Manner

Abstract

There is a very narrow margin in selenium deficiency and toxicity although it is an important element for humans, animals, and plants. Effects of selenium (Se) on the growth and physiomorphological parameters in maize were studied grown in soil spiked with sodium selenate (Na2SeO4) in 5 different concentrations (i.e., 0. 2.5, 5.0, 10.0, and 20.0 mg kg−1). The growth of plants was affected by high Se concentration. However, maximum increases in plant height and root length were observed at low Se (2.5 mg kg−1) which were 17.89 and 23.17%, respectively. At higher Se concentrations (20 mg kg−1), a considerable reduction was observed in dry matter, root length, antioxidant enzymes, and other physiological parameters. The dry matter of plants was also analyzed for nutrient (Fe and Zn) concentrations. Results indicated that Se stress inhibits plant growth. Gas exchange parameters were also found to be decreased under stress conditions, but at a lower Se level (2.5 mg kg−1), improvement in transpiration rate (63.46%), photosynthetic rate (47.47%), and stomatal conductance (54.55%) was observed. The reduction in growth attributes may be due to the high accumulation of Se in roots and the disturbance in gas exchange parameters. However, the principal component analysis revealed that higher Se levels were more hazardous for maize growth and physiological responses as compared to low Se levels.

Uses of Selenium Nanoparticles in the Plant Production

“…Maize handled with selenite (5-100 M) has shown enhanced levels of phosphorus (P) and calcium (Ca + ) content, but decreased potassium (K) content. Tall fescue and white clover that had been treated with hydrogen selenate showed increased Ca + bioconcentration and a decrease in P concentration in the opposite direction [6]. Se toxicity is unquestionably a result of the accumulation of excess Se within the plant cell and the competition among Se and S for the addition of structural components or involvement in biochemical reactions due to the chemical structural similarity between them.…”

“…Even though Se is not an indispensable mineral for higher plants, it must be applied to soil to arrange sufficient nutritional needs for animals and humans. Therefore, the safety margin of Se concentrations should be stressed as relatively narrow [6]. Furthermore, plants have the potential to play significant roles in alleviating Se deficiency and toxicity in a variety of regions around the world; therefore, understanding the wide-ranging mechanism of Se metabolism is essential for effective Se biofortification strategies [7].…”

Biofortification with selenium increases bioactive compounds and antioxidant capacity in tomato fruits

“…The citric acid expressed in titratable acidity, is produced from the oxidation of sugars during respiration and metabolic activity (García-Sahagún, Martínez, Avendaño, Padilla, and Izquierdo, 2009;Beckles, 2012). The addition of Se to the nutrient solution influences the activation of respiration and production of ethylene (Hossain et al, 2021;Naseem et al, 2021) since it controls the synthesis of citric acid, activating phosphorylation as part of respiration and the synthesis of ethylene dependent on the energy available to generate organic acids (Larskaya, Barisheva, Zabotin, and Gorshkova, 2015); decreasing the ripening processes as the fruit cycle progresses (Garduño and Márquez, 2018). Tomatoes are climacteric fruits and their ripening is accompanied by changes in flavor, texture, color and aroma.…”

Biofortification of Horticultural Crops With Selenium

“…Se concentration in air is generally low, ranges from 1 to 10ng.m -2 (Mehdi et al 2013). Selenium concentrations in plants vary depending upon specie, accumulation capacity and selenium levels in soils (Dumont et al 2006;Pilon-Smits 2019;Ramkissoon et al 2019;Naseem et al 2021).…”