Comparative effects of biologically synthesized Zn and Cu NPs on callus induction and physiological traits of chicory (Cichorium intybus) in vitro

This study investigated the properties of copper (Cu) and zinc (Zn) nanoparticles (NPs) biosynthesized using the aqueous extract of moringa. The size and structure of the metal NPs derived from the moringa plant aqueous extract were confirmed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). Chlorophyll a, b, total chlorophyll, carotenoids, proline, and fresh and dry weights of callus were measured. The study aimed to optimize callus production in chicory by first synthesizing Zn and CuNPs using moringa aqueous extract. The size and structure of the biosynthesized Zn and CuNPs were then examined using SEM and XRD. Subsequently, the effects of different concentrations of these biosynthesized Zn and CuNPs on chlorophyll a, b, total chlorophyll, carotenoids, proline, and fresh and dry weights of callus were evaluated under in vitro culture conditions. Electron microscopy images confirmed the synthesis of Cu and ZnNPs, which were spherical with average particle sizes of 8 nm and 12 nm, respectively. The highest values for chlorophylls, fresh weight, and dry weight of callus were obtained with 100 mg/l CuNPs. The highest proline content was achieved with 150 mg/l CuNPs, while the highest carotenoid content was observed with 100 mg/l ZnNPs. Overall, the use of Cu and ZnNPs demonstrated that the strongest positive direct effects were on proline (0.708) and callus fresh weight (1.091), whereas the weakest direct effects, which were negative, were on chlorophyll b (− 0.218) and chlorophyll a (− 0.605).