Data Sheet 1_Nitrogen form regulates ginsenoside biosynthesis in Panax ginseng adventitious roots: comparative transcriptomics of ammonium- and nitrate-mediated pathways.doc

Physiological results showed that nitrate nitrogen supply significantly increased adventitious root biomass and total ginsenoside content compared with ammonium nitrogen. Functional enrichment analysis of transcriptomic data revealed significant transcriptional remodeling in terpenoid biosynthesis, plant hormone signal transduction, and redox homeostasis pathways. Further analysis showed that the core genes of ginsenoside synthesis pathway were upregulated under nitrate nitrogen conditions.

Nitrate treatment also resulted in higher levels of endogenous IAA and CTK and activation of most hormone signaling pathways, whereas ammonium nitrogen induced a significant increase in CAT and POD antioxidant enzyme activities. Nitrate nitrogen can promote endogenous nitric oxide (NO), and further pharmacological experiments suggest that NO likely acts as an important intermediate signal contributing to nitrate-driven promotion of adventitious root growth and ginsenoside synthesis.

The results clarify the molecular mechanism of nitrogen form regulating ginseng secondary metabolism and provide a theoretical basis for optimizing the nitrogen strategy of ginseng adventitious root culture and improving the yield of ginsenosides.</p>