Medicago sativa L. Plant Response against Possible Eustressors (Fe, Ag, Cu)-TiO2: Evaluation of Physiological Parameters, Total Phenol Content, and Flavonoid Quantification

Abstract

The present study analyzed Medicago sativa L. crops irrigated by TiO2 in the anatase phase and TiO2 doped with Ag, Fe, and Cu ions at 0.1%w synthesized using the sol–gel method (SG) and the sol–gel method coupled with microwave (Mw-SG). The materials were added to the irrigation water at different concentrations (50, 100, and 500 ppm). Stress induction by nanomaterials was observed by measuring stem morphology, chlorophyll index, total phenols and flavonoids, and antioxidant activity through the DPPH (2,2-diphenyl-1-picrylhydrazy) radical inhibition assay. The nanomaterial treatments caused statistically significant reductions in parameters such as stem length, leaf size, and chlorophyll index and increases in total phenol content and DPPH inhibition percentage. However, the observed effects did not show clear evidence regarding the type of nanomaterial used, its synthesis methodology, or a concentration-dependent response. By generally grouping the results obtained to the type of dopant used and the synthesis method, the relationship between them was determined employing a two-way ANOVA. It was observed that the dopant factors, synthesis, and interaction were relevant for most treatments. Additionally, the addition of microwaves in the synthesis method resulted in the largest number of treatments with a significant increase in the total content of phenols and the % inhibition compared to the traditional sol–gel synthesis. In contrast, parameters such as stem size and chlorophyll index were affected under different treatments from both synthesis methods.

Efficacy of Carbon Nanodots and Manganese Ferrite (MnFe2O4) Nanoparticles in Stimulating Growth and Antioxidant Activity in Drought-Stressed Maize Inbred Lines

“…In addition, tomato plants treated with 250 mg L −1 SiO 2 NP showed 3.5% higher antioxidant activity in hydrophilic compounds than control plants [ 77 ]. A remarkable increase in DPPH free radical inhibition was observed in Medicago sativa leaves treated with 50 or 100 ppm TiO 2 NM [ 78 ], supporting most of the DPPH results of the present study ( Figure 5 ).…”

Impact of Biologically and Chemically Synthesized Zinc Oxide Nanoparticles on Seed Germination and Seedlings’ Growth

“…The primary function of TPC is to protect plants from oxidative damage [58]. At the same time, TPC can improve metabolic pathways, leading to larger plants, better nutritional content [69], and increased resistance to biotic and abiotic stresses [70]. The response of the seedlings, with respect to TPC, was similar for both nanoparticles; nonetheless, BZnONP increased the content of secondary metabolites, significantly affecting other characteristics of seedlings, eventually leading to products with added value.…”

“…The primary function of TPC is to protect plants from oxidative damage [58]. At the same time, TPC can improve metabolic pathways, leading to larger plants, better nutritional content [69], and increased resistance to biotic and abiotic stresses [70].…”