Phytosynthesis of poly (ethylene glycol) methacrylate-hybridized gold nanoparticles from C. tuberculata: their structural characterization and potential for in vitro growth in banana

Here, we are analyzing the comparative study of green-synthesized biogenic Caralluma tuberculata gold nanoparticles (Ca-AuNPs) and poly (ethylene glycol) methacrylate coated Ca-AuNPs nanocomposites (PEGMA-AuNPs), formed by hybridization of Ca-AuNPs with PEGMA. Both the virgin and polymer-capped materials (polymer hybrid) were physico-chemically characterized, using Fourier transform infrared spectroscopy (FTIR) that revealed physical interactions during coating without new peak, as PEGMA did not disturb the crystal structure of the AuNPs. However, a red shift of AuNPs from 450 to 520 nm was observed and the overall particle size of AuNPs was increased after PEGMA coating (50 to 100 nm). Furthermore, an efficient protocol of biomass enhancement of in vitro micropropagated Musa acuminate was achieved upon supplementation with Ca-AuNPs and PEGMA-Ca-AuNPs, in the Murashige and Skoog (MS) media in a dose-dependent manner. The maximum fresh, dry weight, and shoot length were achieved upon 80 ppm PEGMA-Ca-AuNPs supplementation. In the physiological analysis, higher chlorophyll content, abundant soluble sugar, and elevated moisture content also appeared upon 80 ppm PEGMA-AuNPs addition. Phytohormone analysis showed over-accumulation of IAA content, while on contrary, decreased MDA and H2O2 content, higher production of phenolics, flavonoids, phenylalanine ammonia lyase activity, and antioxidant activity was noticeable upon 80 ppm PEGMA-AuNPs supplementation. Moreover, enhanced antioxidant enzyme activities including CAT, SOD, POD, and APx were detected at 80 ppm PEGMA-Ca-AuNPs supplementation in MS media. It can be concluded that the PEGMA-AuNPs elicitation can be effectively used in plant tissue culture and agricultural industry, for sustainable promotion of biomass and secondary metabolic through modulating the physiological, biochemical, and bioactive antioxidants status and modifying cell wall properties.