Role of metal nanoparticles in organogenesis, secondary metabolite production and genetic transformation of plants under in vitro condition: a comprehensive review

Nanomaterials usually have specific characteristics due to their incredibly tiny size, which also increases their surface area, providing a more interactive surface. Compared to their macro-sized counterparts, these tiny nanoparticles exhibit a multitude of size-dependent properties. Plant tissue culture (PTC) plays an important role in bioactive chemical synthesis, mass cultivation, protection, genetic control, and plant enhancement. Different nanoparticles (NPs) are utilized to improve the tissue culture responses of explants. Various nanoparticles, including cobalt, copper, silver, gold, zinc, selenium, titanium, iron, palladium, cerium, indium, manganese, aluminum, barium, silicon, nickel, zirconium, and their oxides, are used in this regard. Nowadays, it is critical to use nanosystems in conjunction with PTC for mass reproduction, conservation, genetic engineering, crop enhancement, and the synthesis of bioactive compounds. Nanostructured metal oxides play an important role in in vitro plant cultivation. The use of metal nanoparticles (MNPs) has successfully removed microbial contaminants from explants and had a favorable impact on organogenesis (increasing the growth of shoots, roots, and multiplication ratios), callus induction, metabolic changes, and the synthesis of secondary metabolites (NPs are used as elicitors or stress agents). Additionally, NPs cause somaclonal variation (modifications to DNA), improve cryopreservation (increasing the survival rate), and enhance genetic transformation (facilitating gene transformation to bypass the plant cell wall barrier and accelerating protoplast isolation). This review aims to summarize the current breakthroughs achieved by integrating nanotechnology with PTC. Graphical abstract: (Figure presented.)