Uptake, translocation and biotransformation of selenium nanoparticles in rice seedlings (Oryza sativa L.)

Abstract

Background: Selenium (Se) in soil mainly consists of selenite, selenate, and elemental Se. However, little is known about the mechanism involved in the uptake and biotransformation of elemental Se by plants. Results: In this study, the uptake, translocation, subcellular distribution and biotransformation of selenium nanoparticles (SeNPs) in rice (Oryza sativa L.), and a comparison with selenite and selenate, were investigated through hydroponic experiments. The study revealed that SeNPs could be absorbed by rice plants; and aquaporin inhibitor was responsible for a 60.4% inhibition of SeNP influx, while metabolic inhibitor was ineffective. However, the SeNPs uptake rate of rice roots was approximately 1.7 times slower than that of selenite or selenate. Under the SeNPs or selenite treatment, Se was primarily accumulated in roots rather than in shoots, whereas an opposite trend was observed with selenate treatment. Additionally, most of the absorbed Se was distributed in cell wall of the SeNPs or selenite treatedrice plants, while its proportion was the highest in soluble cytosol of the selenate treated-rice plants. The absorbed SeNPs or selenite was rapidly assimilated to organic forms, with SeMet being the most predominant species in both shoots and roots of the rice plants. However, following selenate treatment, Se(VI) remained as the most predominant species, and only a small amount of it was converted to organic forms. Conclusion: Therefore, this study provides a deeper understanding of the mechanisms associated SeNPs uptake and biotransformation within plants.

Uses of Selenium Nanoparticles in the Plant Production

“…SeNPs pass through a cell wall and penetrate the plasma membrane. Only NPs aggregates with diameters smaller than pore diameter could pass through the cell wall successfully [41]. The cell wall of the plant acts as a barrier, preventing easy entry of any external influences, including SeNPs, into the plant's cell walls.…”

“…These sieving properties are determined by the pore size of the cell wall, which can range from 5 to 20 nm [42]. It was shown that SeNPs could abide by plant roots and could influence a chemical and physical uptake in plants [41]. The most widely accepted explanation for the translocation of engineered nanomaterials is that such nanomaterials can start moving intracellularly and extracellularly among the plant tissues until they reach the xylem [43].…”

Selenium Promotes Sunflower Resistance to Sclerotinia Sclerotiorum by Regulating Redox Homeostasis and Hormonal Signaling Pathways

“…Additionally, Se speciation in leaves was distinguished by high-performance liquid chromatography coupled to hydride generation atomic uorescence spectrometry (HPLC-AFS; SA-20, Beijing Jitian Instruments, Beijing, China) with three biological replicates (Wang et al 2020). Brie y, 0.8 g of fresh leaves of SeUn or Un was hydrolyzed by 5 mL of 8 mg mL − 1 protease XIV (Sigma-Aldrich, St. Louis, MO, USA) at 37℃ for 12 hours.…”

Selenium biofortification for human and animal nutrition

“…Previous studies have identified the potential of SeNPs to promote plant growth, increase Se uptake and improve plant quality (Domokos-Szabolcsy et al, 2012;Hussein et al, 2019). The beneficial effects of SeNPs have been shown for several plants, including tomato (Hernandez-Hernandez et al, 2019;Morales-Espinoza et al, 2019), pomegranate (Zahedi et al, 2019), wheat (Hu et al, 2018), rice (Wang et al, 2020a), garlic (Li et al, 2020) and tobacco (Domokos-Szabolcsy et al, 2012). Besides, SeNPs have lower toxicity for plants compared to selenite and selenate (El-Ramady et al, 2020;Li et al, 2020).…”

“…Besides, SeNPs have lower toxicity for plants compared to selenite and selenate (El-Ramady et al, 2020;Li et al, 2020). SeNPs taken up by plants were quickly oxidized to selenite and transformed to organic Se species (e.g., SeCys, SeMet and MeSeCys) in the plant root (Hu et al, 2018;Wang et al, 2020a). However, further investigations are still required to understand the phytotoxicity of SeNPs on various plants and the potential risks to the environment of using SeNPs.…”