Steady-state and time-resolved fluorescence of chlorophyll extracted of sunflower seedlings primed with green synthesized silver and copper nanoparticles

Nanopriming is a pre-sowing treatment in which seeds are soaked in nanoparticle solutions for a determined period. This process enhances germination performance, vigor index, and plant tolerance to biotic and abiotic stresses, reducing pesticides and fertilizers. This work aimed to study the germination of sunflower seeds primed at 25 °C for 24 h with Mimusops coriacea (Mc) leaf extract and silver and copper nanoparticles prepared with Mc extract and verify the effect of nanopriming in seedling development by obtaining fluorescence properties of the chlorophyll extract of the treated seedlings. McNPs were synthesized by the photoreduction process (Mc extract as stabilizing/capping agent) and characterized by UV–Vis, transmission electron microscopy, FTIR, and Zeta potential. The germination percentage, shoot length (SL), root length (RL), seedling vigor index (Vi), and chlorophyll fluorescence steady-steady and decay time were obtained on the 3rd, 6th, and 10th days after the priming process. According to the results, sunflower seed priming with Mc extract and McNPs enhanced germination capacity, seed growth, and increased chlorophyll production compared to water-primed seeds. Differences in chlorophyll fluorescence profile were observed in highly concentrated silver nanoparticles 6 days after the priming process. A quenching of the chlorophyll fluorescence lifetime indicated the presence of an energy transfer process between chlorophyll and lutein. Graphical abstract