Competence of omeprazole and chitosan nanoparticles as promising approaches for enhancing vegetative growth and leaf anatomical structure of plum under low nitrogen conditions

Reducing the requirements of chemical fertilizers has emerged as a critical target with economic and environmental concerns in agricultural sector. Consequently, there is a growing need for research focused on developing sustainable approaches to enhance fertilizer use efficiency. Omeprazole (OMZ) and chitosan nanoparticles (ChNPs) have shown promising results and are considered as growth promoters. However, to the best of our knowledge there are no available data about the application of OMZ on fruit trees. Decreasing utilization rate of N chemical fertilizers while maintaining optimal growth of plum plants (Solar Eclipse and Suplum 41 cvs.) as changes related to vegetative growth and leaf anatomy by application of OMZ and ChNPs had been investigated under low nitrogen conditions. Plum grafted seedlings of each cultivar are divided to four groups: (a) Plants received 10 mM NO3−, (b) Plants received 2 mM NO3−, (c) Plants received 2 mM NO3− loaded on ChNPs, and (d) Plants received OMZ + 2 mM NO3−. ChNPs were synthesized using the ionotropic gelation and characterized by transmission electron microscope and zetasizer. Vegetative growth parameters including plant height, stem diameter, number of leaves per plant, and leaf area were measured. Photosynthetic pigments and total N content in leaves of plum plants were analyzed. Leaf anatomy was performed to identify leaf structural changes in response to different treatments. One-way analysis of variance was performed for statistical analysis and significant differences (α ≤ 0.05) were determined using Duncan’s multiple range test. The obtained results revealed that ChNPs and OMZ enhanced vegetative growth and leaf structure compared to untreated plants, even when receiving low nitrogen (2mM NO3−) or high (10 mM NO3−). Plum plants treated with OMZ exhibited improvement in growth and leaf structure higher than ChNPs under low nitrogen conditions. OMZ and ChNPs could be a cost-effective way to save amounts of chemical fertilizers added to soil and increase nutrient use efficiency.