Silver Nanoparticles Increase Nitrogen, Phosphorus, and Potassium Concentrations in Leaves and Stimulate Root Length and Number of Roots in Tomato Seedlings in a Hormetic Manner

Abstract

Background Silver nanoparticles (AgNPs) display unique biological activities and may serve as novel biostimulators. Nonetheless, their biostimulant effects on germination, early growth, and major nutrient concentrations (N, P, and K) in tomato ( Solanum lycopersicum) have been little explored. Methods Tomato seeds of the Vengador and Rio Grande cultivars were germinated on filter paper inside plastic containers in the presence of 0, 5, 10, and 20 mg/L AgNPs. Germination parameters were recorded daily, while early growth traits of seedlings were determined 20 days after applying the treatments (dat). To determine nutrient concentrations in leaves, a hydroponic experiment was established, adding AgNPs to the nutrient solution. Thirty-day-old plants were established in the hydroponic system and kept there for 7 days, and subsequently, leaves were harvested and nutrient concentrations were determined. Results The AgNPs applied did not affect germination parameters, whereas their application stimulated length and number of roots in a hormetic manner. In 37-day-old plants, low AgNP applications increased the concentrations of N, P, and K in leaves. Conclusion As novel biostimulants, AgNPs promoted root development, especially when applied at 5 mg/L. Furthermore, they increased N, P, and K concentration in leaves, which is advantageous for seedling performance during the early developmental stages.

The Effect of Bio-Synthesized Silver Nanoparticles on Germination, Early Seedling Development, and Metabolome of Wheat (Triticum aestivum L.)

“…This means that Ag NPs at low concentrations (0.5–1 mg/L) stimulated root growth, while at higher concentrations (5–20 mg/L), they had an inhibitory effect. Similar responses to Ag NPs were found in the roots of barley [ 38 , 39 ] and tomato [ 42 , 43 ] seedlings.…”

“…Moreover, fluorescence that indicated ROS formation was observed in root tip cells ( Figure 4 A,B, red arrows show enlarged images) in wheat seedlings of control and treated with 10 mg/L (Bio)Ag NPs, whereas in the grain and seedling treated with 20 and 40 mg/L (Bio)Ag NPs, it was observed in the apical meristem region ( Figure 4 C,D, red arrows show enlarged pictures). Increasing ROS formations in epidermal cells cause a peroxidation of membrane lipids [ 28 , 34 , 41 , 42 ], membrane damage [ 41 ], and cell apoptosis [ 43 , 44 ]. Excess ROS can also stimulate cell wall lignification and callose deposition [ 44 , 45 ].…”

Low-level cadmium exposure induced hormesis in peppermint young plant by constantly activating antioxidant activity based on physiological and transcriptomic analyses

“…In order to test whether the effects of Cd treatments on peppermint growth performance is hermetic, the data on fresh weight of the whole plant were adjusted to the Brain and Cousens model ( Lushchak, 2014 ; Guzmán-Báez et al., 2021 ). An inverted U-shaped dose-response hormetic curve was noted, which was characterized by stimulation at low Cd concentrations but inhibition at high Cd concentrations ( Supplementary Figure 2 ).…”

Metabolomics as a Tool to Understand Nano-Plant Interactions: The Case Study of Metal-Based Nanoparticles

“…However, nAg applications go beyond that, and they are also used in electronics, sensors, and solar cells [ 121 ]. In the agricultural sector, nAg have been explored as plant-stimulants [ 122 ], stress mitigators [ 123 ], and fungicides [ 124 ], despite the diverse studies also demonstrating their potential phytotoxicity [ 25 , 125 , 126 ]. The effects of nAg on plant metabolome are summarized in Table 3 .…”