Nano-chelated nitrogen improves in vitro shoot growth of potato (Solanum tuberosum L.) as a novel nitrogen source

Efficient nitrogen management is essential for sustainable plant production and environmental protection, and nano-based nitrogen fertilizers may provide an alternative approach to improve nitrogen-use efficiency and reduce nitrogen losses. We evaluated nano-chelated nitrogen (NCN) across a 2.6–20.77 mM range for the growth of Solanum tuberosum L. cv. Agria one-node cuttings under in vitro conditions, using 20.6 mM NH₄NO₃ (equivalent to 41.2 mM total nitrogen) as a control. NCN was synthesized via a nano-chelation strategy forming a crystalline architecture in which nitrogen is hypothesized to be stabilized through multidentate coordination within layered structures. Dose–response optimization using Differential Evolution identified an optimal NCN concentration (~ 5.5 mM), which was subsequently compared with the control treatment. Despite an 86.6% reduction in nitrogen input, NCN-treated plantlets exhibited 72% greater shoot length, 71% greater internode elongation, and 24% greater fresh biomass than those grown on the standard NH₄NO₃-containing medium. Although SPAD index and shoot nitrogen content decreased, an increased chlorophyll a/b ratio suggested altered photosynthetic organization under reduced nitrogen availability. Root nitrogen levels remained comparable to controls, suggesting the maintenance of root nitrogen homeostasis. These findings suggest that NCN can enhance nitrogen-use efficiency and biomass production in vitro, highlighting its potential for resource-efficient nanobiotechnological micropropagation systems.