Biological mechanisms of sodium nitroprusside in enhancing quality of Radix Paeoniae Rubra and Radix Paeoniae Alba.

Introduction: Both Paeoniae Radix Alba (RAP) and Paeoniae Radix Rubra (RRP) are important botanical drugs used in Asian countries. Although they are both derived from the roots of Methods: Fresh roots of Results: In the fresh roots of RRP-germplasm treated with 0.5 mmol/L SNP, the secondary metabolites paeoniflorin, albiflorin, oxypaeoniflorin, gallic acid, catechin, and paeonol were elevated by 19.1%, 205.4%, 115.4%, 19.9%, 201.0%, and 585.2%, respectively, and in the fresh roots of RAP-germplasm treated with 2.5 mmol/L SNP, the major secondary metabolites paeoniflorin, albiflorin, oxypaeoniflorin, gallic acid, catechin, and benzoic acid showed increases of 25.4%, 70.4%, 95.1%, 6.7%, 86.5%, and 33.6%, respectively. Moreover, experiments involving combined treatment with SNP and ROS scavengers demonstrated that ROS act as the key mediator linking exogenous NO to the secondary metabolism of Discussion: Combined with the above findings of SNP promoting secondary metabolite synthesis, this study confirms that exogenous NO can improve the quality of cultivated RAP and RRP via ROS-mediated secondary metabolism, and clarifies the NO-ROS-secondary metabolism regulatory axis, offering insights for other medicinal plants' quality improvement.