Dynamic Modeling of Silicon Bioavailability, Uptake, Transport, and Accumulation: Applicability in Improving the Nutritional Quality of Tomato

Abstract

Silicon is an essential nutrient for humans, additionally is beneficial for terrestrial plants. In plants Si enhances tolerance to different types of stress; in humans, it improves the metabolism and increases the strength of skeletal and connective tissues as well as of the immune system. Most of the Si intake of humans come from edible plants creating a double benefit: first, because the absorption of Si increases the antioxidants and other phytochemicals in plants, thereby increasing its functional value, and second because the higher concentration of Si in plants increases intake in human consumers. Therefore, it is desirable to raise the availability of Si in the human diet through the agronomic management of Si accumulator species, such as corn, wheat, rice, soybeans, and beans. But also in such species as tomatoes, carrots, and other vegetables, whose per capita consumption has increased. However, there are few systematized recommendations for the application and management of Si fertilizers based on the physicochemical factors that determine their availability, absorption, transport, and deposition in cells and tissues. This study presents updated information about edaphic and plant factors, which determine the absorption, transport, and deposition rates in edible organs. The information was integrated into an estimated dynamic model that approximates the processes previously mentioned in a model that represents a tomato crop in soil and soilless conditions. In the model, on the other hand, was integrated the available information about key environmental factors related to Si absorption and mobilization, such as the temperature, pH, and soil organic matter. The output data of the model were compared against information collected in the literature, finding an adequate adjustment. The use of the model for educational or technical purposes, including the possibility of extending it to other horticultural crops, can increase the understanding of the agronomic management of Si in plants.

Mineral Biofortification of Vegetables as a Tool to Improve Human Diet

“…This would explain the strong differences in Si concentration reported within tissues of different plants species [ 141 ]. In any case, Si is taken up by the roots as monosilicic acid with the involvement of channels belonging to the aquaporins’ group, so the water flow resulting from leaf transpiration seems to play a determinant role in defining the rate of Si absorption and transport within the plant [ 142 ]. Once absorbed, monosilicic acid is subsequently translocated to the shoot through the xylem flow, where Si is concentrated thanks to transpiration and polymerized to silica (SiO 2 ), then deposited in the different tissues [ 143 ].…”

“…Plants markedly differ in their ability to accumulate Si in their various organs; concentrations ranging between 5 and 50 g kg −1 DW have been reported as critical for some species. The species with low mobilization capacity accumulate it in the roots and stems, while the species with high mobilization capacity accumulate Si in stems, leaves, fruits, and seeds [ 142 ]. Gao et al [ 145 ] noticed that excessive Si supply (>2 mM) caused the formation of Si polymers on root surfaces, a feature that could affect nutrients uptake.…”

“…In spite of the scarcity of available information, this aspect would deserve extensive study with reference to vegetable crops, due to their potential role as Si source in the human diet. Indeed, thanks to their usually low silicification capacity, vegetable crops are expected to contain high amounts of soluble Si, which is theoretically more available to be assimilated after ingestion, so potentially being optimal candidates as Si source in the human diet [ 142 ]. As shown in Table 1 , as regards the leafy vegetables, in a study concerning six crops grown in a greenhouse floating system, namely Brassica rapa L. (tatsoi and mizuna group), Ocimum basilicum L., Portulaca oleracea L., Cichorium intybus L. and Beta vulgaris L. ssp.…”

Do soil and leaf silicon content affect leaf functional traits in Deschampsia caespitosa from different habitats?

“…No correlation between soil and leaf samples for plant-available Si could be the consequence of the changes in its availability during the growing season, as the solubility of silica in the soil is affected by soil processes, soil pH, the presence of organic complexes and aluminium, iron, and phosphate ions, dissolution reactions, and soil moisture (Rao et al 2017). In spite of the lower total soil Si content in the alpine heath soil from below the summit of Mount Komen, one would assume that the soil from this habitat was richer in plant-available Si, as it has been shown that the bioavailability of Si can increase with greater soil organic matter content (López-Pérez et al 2018). However, this was not the case here.…”

NO Network for Plant–Microbe Communication Underground: A Review

“…Significant quantity of silicon present in the soil makes it the second most abundant element on the earth’s crust, and hence studies were carried out to understand its role in the rhizosphere. It was discovered that silicon could not only increase the biomass production but also had role in enhancing tolerance to biotic and abiotic stresses, thus supporting plants with stability and protection ( Luyckx et al, 2017 ; López-Pérez et al, 2018 ). Interestingly, a study also discovered silicon uptake transporters from some legumes like soybean which were similar to the silicon transporters in hyper accumulating grasses ( Deshmukh et al, 2013 ).…”