The use of silver nanoparticles (AgNPs) has gained importance in agriculture in recent years thanks to their unique characteristics, including their antimicrobial capacity and their ability to promote plant growth. Due to these attributes, AgNPs are considered a promising solution for the future of agriculture, offering significant potential to address the challenges the sector confronts currently. However, it is important to adjust the application conditions, depending on the target and the crop used, to improve AgNP treatment efficiency. This review compiles recent advances in the use of AgNPs for crop production, both in and ex vitro. AgNPs promote growth and alleviate biotic and abiotic stresses through different ex vitro application methods. They are also efficiently used in vitro to improve plant culture and pathogen elimination. In addition, the safety and toxicity associated with their use are discussed. AgNPs are a novel tool with great potential for the agricultural sector, but it is still necessary to continue researching the mechanisms of AgNP action in order to optimize their application in each specific case.

Metallic nanoparticles have antimicrobial, virucidal, and anticancer activities and have been widely applied in medicine. In plants, silver nanoparticles have been used as preventive treatments in the greenhouse to reduce viral titers and symptoms. This work investigates the effect of Argovit™ AgNP formulation on apricot plants infected with Plum pox virus or with Hop stunt viroid. Meristems were rescued from plants treated with different Argovit™ concentrations and two exposure times. Although viroid-free plants were not obtained, a very high efficiency in eliminating the sharka virus is reported with a maximum cleaning efficiency (75 %) after 8 weeks of exposure at 75 mg L^-1 AgNP. To the best of our knowledge, this is the first time that silver nanoparticles application is used, combined with meristem culture, to produce virus-free plants and opens a new path to the elimination of viruses from plants.

Application of silver nanoparticles (AgNPs) represents a strategy with great potential for in vitro culture and plant material sanitisation, thanks to their growth-promoting and antimicrobial properties. However, their effectiveness depends largely on the formulation, particularly the surface coating, as well as the plant species. In this study, the effect of two AgNP formulations with different coatings was evaluated: Argovit™-C (Ag-C), stabilized with polyvinylpyrrolidone and protein hydrolysate and BioArgovit™ (Bio-Ag), stabilized only with protein hydrolysate; on growth, micropropagation and physiological response of apricot (Prunus armeniaca L.) ‘Canino’ shoots, infected with Plum pox virus (PPV) or Hop stunt viroid (HSVd), and cultured in vitro. The results showed that Ag-C significantly promoted micropropagation in PPV-infected shoots, increasing proliferation and productivity, particularly at intermediate doses (50–75 mg L⁻¹), without inducing significant physiological changes or residual silver accumulation following the ex vitro acclimatisation phase. In contrast, Bio-Ag had no significant effect on any of the parameters evaluated. Ionomic analysis revealed that Ag-C induced changes in nutrient uptake, associated with higher levels of C, Fe and Cu, which could explain its growth-promoting effect. In shoots infected with HSVd, Ag-C did not improve micropropagation, indicating that the response to treatment is strongly dependent on the pathogen. Overall, these results highlight the crucial role of the surface coating in modulating the biological activity of AgNPs and suggest that Ag-C is an effective and safe formulation for in vitro culture applications, although its efficacy is dependent on a marked interaction with the pathogen infecting the plant.