Synergistic effects of plant growth regulators and fe₃o₄ nanoparticles on in vitro organogenesis and bioactive compound production in hypericum perforatum
Khawlah Mahmood Al Nooh, Aysar Mohammed Salim, Waad S. Faizy, Soheila Aghaei Dargiri, Heidar Meftahizadeh
Abstract
This study investigated the combined effects of plant growth regulators (2,4-D and kinetin) and iron oxide nanoparticles (Fe₃O₄-NPs) on in vitro morphogenesis and secondary metabolite production in Hypericum perforatum L. The optimized treatment [2,4-D (0.5 mg/L) + kinetin (2 mg/L) + Fe₃O₄-NPs (4 mg/L)] significantly enhanced growth parameters, showing increases of 59.6% in plant height, 114.0% in root length, and 180.0% in shoot number, as well as a 198.3% increase in callus fresh weight compared with the control. This combination also improved regeneration efficiency (50.85%) and increased hypericin content by 66.6%. GC-MS profiling revealed high levels of hypericin, hyperforin, β-patchoulene, and hexadecanol, accounting for 93.36% of the total peak area, while total phenolic and flavonoid contents increased by up to 80.1%. These findings demonstrate the synergistic role of PGRs and Fe₃O₄-NPs in enhancing both organogenesis and bioactive compound accumulation, providing a promising strategy for the biotechnological improvement of medicinal plants.