Beneficial dose-dependent effects of Ag nanoparticles on germination do not compromise growth and metabolic profiles of <i>Capsicum annuum</i> seedlings

This study evaluates the effects of silver nanoparticles (AgNPs) as a nanopriming agent and their potential detrimental impacts on growth and physiology in wild and domesticated chili (<i>Capsicum annuum</i>) seeds. We compared the responses of wild (<i>C. annuum</i> var. <i>glabriusculum</i>) and domesticated (Serrano) plants. Seeds were soaked for 24 hours in AgNP solutions at concentrations of 0 ppm, 50 ppm, 100 ppm, and 250 ppm. Germination was monitored daily over a 14-day period in replicated Petri dishes under controlled growth chamber conditions. A subsample of germinated seedlings from each treatment was transplanted into plastic pots to assess plant growth and secondary metabolism at 28 and 42 days after germination. On each sampling day, three randomly selected plants per treatment were evaluated for shoot and root length, as well as wet and dry biomass. Physiological measurements included both primary and secondary metabolites, specifically chlorophyll and polyphenols. Potential genotoxic effects were assessed by exposing meristematic root tissue to a 5 ppm AgNP solution for 72 hours and analyzing mitotic activity. The results showed that AgNPs significantly increased germination in wild chili, reaching 90% compared to 77% in the control, without negative effects on plant development. No significant differences were observed in growth traits or polyphenol content, or the number of dividing cells. Furthermore, no chromosomal aberrations were detected. The beneficial effects of nanopriming were limited to the germination stage in wild plants, and no enhancement was observed in the domesticated variety. These results suggest that domestication may reduce sensitivity to nanopriming. Overall, our findings support the potential benefits and safety of AgNP-based nanopriming in agriculture, even at high concentrations.