Influence of metal and metal oxide nanoparticles on growth and total phenolic content accumulation of Anoectochilus roxburghii cultured in vitro

The application of metal nanoparticles in agriculture and related fields, especially in plant cell tissue culture has increased interest in recent years due to its potential benefits. This study used gold nanoparticles (AuNPs), silver nanoparticles (AgNPs), copper nanoparticles (CuNPs) and magnetite nanoparticles (Fe3O4NPs) to evaluate their effect on the growth and total phenolic content (TPC) of Anoectochilus roxburghii. The results showed that Fe3O4 NPs were the most positively influenced metal nanoparticles in increasing biomass and TPC of A. roxburghii among metal nanoparticles tested. After 8 weeks of culture, the dry weight (DW) and TPC of the plants cultured on the medium containing 5 ppm Fe3O4NPs were 39.07 mg and 13.0 mg gallic acid respectively per g of dry weight (mg GAE/g DW). Meanwhile, on the medium without Fe3O4NPs, they were 30.47 mg and 6.71 mg GAE/g DW respectively. This study proposed an effective approach to improve the growth and accumulation of TPC in A. roxburghii. Moreover, it suggests the potential application of metal nanoparticles in plant tissue culture and the production of bioactive compounds.