Elucidation of biochemical and physiological modulations in Triticum aestivum induced by green synthesized nitrogen-enriched zinc nano-complexes

This study investigates the efficacy of a green synthesized nitrogen-rich zinc complex (Zn-NC) using quinoline (C 9 H 7 N) as the nitrogen-rich substrate to enhance growth and biochemical properties in wheat ( Triticum aestivum ). The performance of Zn-NC was compared to standard zinc oxide nanoparticles (ZnO-NPs). Both Zn-NC and ZnO-NPs were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), and dynamic light scattering (DLS). Three concentrations (100, 200, and 500 ppm) of each compound, along with a control, were applied to local soil samples (n=3). The physiological (biomass, elongation) and biochemical effects (chlorophyll, carotenoids, flavonoids, and phenols) on wheat were investigated. Potential phytotoxic effects were evaluated to establish the biostimulants' safety thresholds. Plants treated with green Zn-NC showed an average increase in shoot length of 25 % compared to the control group. The chlorophyll content in plants treated with ZnO-NPs increased by 18 %, while those treated with green Zn-NC increased by 12 % compared to control. Application of ZnO-NPs resulted in a 30 % increase in total yield, whereas green Zn-NC treatment led to a 22 % yield increase. The root biomass of plants treated with ZnO-NPs increased by 28 %, and those treated with green Zn-NC saw a 20 % increase compared to controls. Based on the optimization of overall results, the ZnO NPs showed phytotoxic effects at concentrations above 200 ppm, while green Zn-NC exhibited no significant phytotoxicity even at concentrations up to 300 ppm. This study delineates the optimal concentrations of Zn-NC and ZnO-NPs that can enhance nutrient delivery and yield in cereal crops while mitigating phytotoxic risks. The findings provide valuable insights into applying nano-biostimulants in agroecosystems, highlighting their potential to improve productivity and sustainability in agriculture. • Zn-NC and ZnO-NPs significantly enhanced the growth and biochemical properties of wheat. • Zn-NC offers an eco-friendly alternative for nitrogen-deficient soils. • Detailed characterization and safety thresholds ensure safe agricultural use. • Determined effective concentrations of Zn-NC and ZnO-NPs for boosting crop yield.