Effect of Selenite and Selenate Application on Mineral Composition of Lettuce Plants Cultivated Under Hydroponic Conditions: Nutritional Balance Overview Using a Multifaceted Study

Abstract

The effect of selenate and selenite enrichment on mineral composition of a red type of lettuce cv. "Veneza roxa" was evaluated using inductively coupled plasma-optical emission spectroscopy (ICP OES), molecular modeling and principal component analysis (PCA). Both Se species did not show toxicity, while selenate promoted the greatest Se accumulation by the plant. There was an increase of 886 µg of Se per 100 g of fresh sample at different concentrations of selenate, but for selenite the maximum variation was only of 114 µg per 100 g. Selenate promoted the absorption of Mo and S and the reduction of K, Mn and P, meanwhile selenite increased Mn and decreased Mo accumulation. Copper and Fe absorption was negatively affected, Ca and Mg showed a slight increase, and Na and Zn were not affected by Se species. Despite the changes in the nutritional balance, Se-enriched lettuce can still be considered a potential dietary source of this essential element.

Combating Micronutrient Deficiency and Enhancing Food Functional Quality Through Selenium Fortification of Select Lettuce Genotypes Grown in a Closed Soilless System

“…Similarly, Smoleń et al (2016b) found a decrease in potassium content by about 9% in green butterhead lettuce leaves treated with selenium combined with iodine. On the other hand, the increase of K and Mg recorded in red Salanova treated with Se was in disagreement with other scientific literature where the authors found no variation in these two macroelements content after selenate applications (Wu and Huang, 1992; Silva et al, 2018a).…”

“…Anyhow, Se leaf content was significantly higher than the control treatment in treatments ≥ 16 µM dose for both cultivars. Our results are in agreement with previous studies on red and green-pigmented lettuce (Ramos et al, 2010; Hawrylak-Nowak, 2013; Silva et al, 2018a) demonstrating the actual feasibility of using lettuce crop in Se biofortification programs.…”

“…Our results are confirmed by White et al (2004) who found that selenate applications promoted the accumulation of sulphate in the shoots of the model plant Arabidopsis thaliana . Similar findings were found in lettuce by several authors (Ramos et al, 2011; Hawrylak-Nowak, 2013; Rios et al, 2013; Silva et al, 2018a), and in particular Rios and co-workers (Ríos et al, 2008) reported an increase in S content in lettuce shoots with Se concentrations up to 40 µM. The first stage in the S-assimilation process consists of the activation of the enzyme ATP-sulfurylase, which produces adenosine phosphosulfate from sulfate and ATP (Pilon-Smits et al, 1999).…”

“…The cultivar-dependent response to supplemental Se observed in our experiment, where the red-pigmented Salanova showed better tolerance to selenate compared to the green one, was in agreement with the study on red lettuce cv. Veneza Roxa by Silva et al (2018a), where no significant reduction in shoot fresh weight was observed with selenate concentrations ranging from 10 to 40 µM. Considering the above, it appears that the beneficial or toxic effect of Se on plant growth and crop productivity may vary in relation to different interacting variables, including the Se concentration, time of exposure and cultivation system (Pedrero and Madrid, 2009).…”

“…Biofortification is the process that increases the bioavailable content of targeted elements in edible plant parts through agricultural intervention or genetic selection (White and Broadley, 2005). In this perspective, recent works have demonstrated that Se fertilization increases the content of this element in a wide range of crops including rice (Chen et al, 2002), wheat (Lyons et al, 2004), radish (Pedrero et al, 2006; Schiavon et al, 2016), spinach (Ferrarese et al, 2012), potato (Turakainen et al, 2004), bean (Hermosillo-Cereceres et al, 2011), soybean (Yang et al, 2003), pea (Jerše et al, 2018), tomato (Schiavon et al, 2013), rocket (Dall’Acqua et al, 2019), lamb’s lettuce (Hawrylak-Nowak et al, 2018), and lettuce (Businelli et al, 2015; Esringu et al, 2015; Smolen et al, 2016a; Silva et al, 2017; Silva et al, 2018a). Se fertilization is a relatively low-cost approach to the prophylaxis of consumers against nutrient deficiency.…”