In vitro iron nanoparticles modulate ginsenoside biosynthesis and trigger ROS-mediated stress response in ginseng...

Enhancing ginsenoside accumulation is essential for improving the medicinal quality of Panax ginseng. Although iron nanoparticles (Fe-NPs) have emerged as promising elicitors of secondary metabolism, their specific effects on ginsenoside biosynthesis remains elusive.

Ginseng adventitious roots were treated with Fe-NP treatment in comparison with a conventional iron source (Fe₃O₄). Physiological responses, ginsenoside profiles, and the expression of key biosynthetic and reactive oxygen species (ROS)-related genes were analyzed to compare elicitation efficiency and potential toxicity.

At a lower concentration (10 ϻM), Fe-NP concentrations markedly induced key ginsenoside-biosynthetic genes and increased total ginsenoside content by 14-16%, whereas equivalent concentrations of Fe₃O₄ caused no significant metabolic changes, demonstrating the superior elicitation efficiency of the nanoparticle formulation. In contrast, higher Fe-NP doses (50-100 μM) caused iron toxicity and suppressed ginsenoside accumulation, likely through excessive ROS generation as supported by strong induction of ROS-detoxification genes. Notably, ginsenoside Re levels increased under iron stress, suggesting a potential antioxidative role.

Overall, our findings reveal a dose-dependent dual effect of Fe-NPs, promoting ginsenoside biosynthesis at optimal doses while triggering ROS-mediated suppression at higher levels, and highlight the importance of precise Fe-NP dosage optimization for biotechnological applications.