Hormetic effect of silver nanoparticles on the micropropagation of Creole pineapple (Ananas comosus)

The in vitro hormetic effect of silver nanoparticles (AgNPs) on the morphogenic response was evaluated on Ananas comosus in this study. Meristems were placed in the Murashige Skoog (MS) medium with different AgNP concentrations (0, 25, 50, 100, 200 mg · L⁻¹), whereby the effect of combining 1 mg · L⁻¹ of 6-benzylaminopurine (BAP) and AgNPs in the afore mentioned concentrations was also assessed. Responses were evaluated after 30 days and 60 days of culture. The best concentration for sprout formation was 50 mg · L⁻¹ of AgNPs, with which 6.33 ± 0.33 shoots per explant were obtained. This response doubled when combined with 1 mg · L⁻¹ of BAP, where 11.33 ± 0.88 shoots per explant were obtained. Concentrations of 50 mg · L⁻¹ and 100 mg · L⁻¹ of AgNPs, either alone or in combination with BAP, stimulated chlorophyll synthesis. When applying 200 mg · L⁻¹ of AgNPs, total phenolic content was higher and the best DPPH response was observed at 50 mg · L⁻¹ of AgNPs, which was enhanced when combined with BAP. These results demonstrated that AgNPs induce direct organogenesis (nanoregulatory effect) in the in vitro culture of pineapple, along with different physiological and biochemical responses in A. comosus shoots.