Silver nanoparticles enhanced shoot regeneration from Begonia × tuberhybrida Voss petal explants via carbohydrate synthesis pathway

Abstract

This study was carried out to optimise the shoot regeneration efficiency from Begonia × tuberhybrida Voss petals on medium supplemented with silver nanoparticles (AgNPs). The results showed that the petal explants cultured on the medium supplemented with 0.8 mg/l Thidiazuron (TDZ) had significantly higher bud regeneration efficiency than other cytokinins investigated. Meanwhile, the addition of 1.5 mg/l AgNPs combined with 0.8 mg/l TDZ increased the number of regenerated shoots 1.67-fold higher than the control without adding AgNPs. The presence of 1.5 mg/l AgNPs in the culture medium stimulated a significantly higher increase in the fresh and dry biomass of shoot clusters (421.49 and 24.73 mg, respectively) compared to the control (241.92 and 12.49 mg, respectively). Analysis of the carbohydrate content in explants by UV-Vis showed that during most of the in vitro regeneration stages, AgNPs stimulated the accumulation of starch (days 5, 10, 20 and 25) and sugars (days 15, 20 and 25) in the explants. The present results indicate that AgNPs promote starch accumulation and conversion to sugar in Begonia × tuberhybrida Voss petal explants, which provide the necessary energy source for in vitro shoot regeneration.