Synthesis and characterization of CeO2 and SiO2 nanoparticles and their effect on growth parameters and the antioxidant defense system in Vigna mungo L. Hepper

Unlocking the potential of SiO2 and CeO2 nanoparticles for arsenic mitigation in Vigna mungo L. Hepper (Blackgram)

In this study, the interaction effects of NaAsO2 (1 and 5 μM), SiO2 NPs (10 and 100 mg/L) and CeO2 NPs (10 and 100 mg/L) were assessed in Vigna mungo (Blackgram). The treatment of NaAsO2, SiO2, CeO2-NPs and combinations of NPs & As were applied to blackgram plants under hydroponic conditions. After its application, the morpho-physiological, antioxidant activity, and phytochemical study were evaluated. At 10 and 100 mg/L of SiO2 and CeO2-NPs, there was an increase in antioxidative enzymatic activity (p < 0.05) and reactive oxygen species (ROS). However, substantial ROS accumulation was observed at 1 and 5 μM NaAsO2 and 100 mg/L SiO2 NPs (p < 0.05). Additionally, at such concentrations, there is a substantial reduction in photosynthetic pigments, nitrogen fixation, chlorosis, and plant development when compared to controls (p < 0.05). The combination of SiO2 and CeO2 NPs (10 and 100 mg/L) with NaAsO2 decreased superoxide radical and hydrogen peroxide and improved SOD, CAT, APX, GR, and chlorophyll pigments (p < 0.05). Further FTIR results were evaluated for documenting elemental and phytochemical analysis.

Boosting plant resilience: The promise of rare earth nanomaterials in growth, physiology, and stress mitigation

Rare earth elements (REE) have been extensively used in a variety of applications such as cell phones, electric vehicles, and lasers. REEs are also used as nanomaterials (NMs), which have distinctive features that make them suitable candidates for biomedical applications. In this review, we have highlighted the role of rare earth element nanomaterials (REE-NMs) in the growth of plants and physiology, including seed sprouting rate, shoot biomass, root biomass, and photosynthetic parameters. In addition, we discuss the role of REE-NMs in the biochemical and molecular responses of plants. Crucially, REE-NMs influence the primary metabolites of plants, namely sugars, amino acids, lipids, vitamins, enzymes, polyols, sorbitol, and mannitol, and secondary metabolites, like terpenoids, alkaloids, phenolics, and sulfur-containing compounds. Despite their protective effects, elevated concentrations of NMs are reported to induce toxicity and affect plant growth when compared with lower concentrations, and they not only induce toxicity in plants but also affect soil microbes, aquatic organisms, and humans via the food chain. Overall, we are still at an early stage of understanding the role of REE in plant physiology and growth, and it is essential to examine the interaction of nanoparticles with plant metabolites and their impact on the expression of plant genes and signaling networks.