Purpose Enzymatic activity in plant signaling, photosynthesis, energy metabolism, and respiratory activities depend on the amount of readily available phosphorus in the soil. Artemisia argyi(A. argyi) is a medicinal plant with antifungal, antiinsect, and anti-inflammatory activities. Our goal was to increase knowledge of the physiological and molecular mechanisms involved in the investigation of the effects of soil phosphorus on important secondary metabolites of A. argyi that regulate growth. Methods At various phosphorus levels, A. argyi was examined for its agronomic characteristics, elemental content in the leaves, generation of significant metabolic chemicals, and molecular mechanisms. Results A. argyi displayed the highest levels of phenolic acids (chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, and neochlorogenic acid) and flavonoids (hispidulin, jaceosidin, eupatilin, and casticin), measured in the leaves, when treated with low levels of phosphorus. P-element levels significantly correlated with the amount of each active ingredient, and transcript Phosphorus levels also affected terpenoid content and the expression of numerous genes involved in the 4-hydroxytoluene pathway (MEP) and the pentadienyl pathway (MVA), which are both necessary for terpenoid production. Conclusions Low levels of phosphorus application enhance the accumulation of medicinal chemicals in A. argyi, medium levels of phosphorus application stimulate the growth of A. argyi, and associated genes are often down-regulated with higher levels of phosphorus application.

No abstract

Nitrogen is a key factor in various physiological and metabolic processes in plants. Providing an adequate supply of nitrogen is essential for improving the total yield and quality of the medicinal plant Artemisia argyi (A. argyi), but the underlying mechanisms of how this nutrient alters the crop remains unclear. In this study, we conducted a series of pot experiments to investigate the agronomic traits and active components in the leaves of A. argyi plants under low and high nitrogen stress. Additionally, we used transcriptome analysis and RT-qPCR to explore the molecular pathways associated with nitrogen stress. Our results demonstrate a dramatic increase in the accumulation of phenolic acids and flavonoids in the low nitrogen (LN) stress group compared to the control (CK), with increases of 40.00% and 79.49%, respectively. Interestingly, plants in the high nitrogen (HN) stress group exhibited enhanced plant growth with larger leaves, thicker stems, and a 3% increase in volatile oil content compared to the CK. Moreover, A. argyi in the HN group displayed a 66% increase in volatile oil concentration compared to the LN group. Our combined transcriptome and q-PCR results indicate that LN stress promotes the expression of genes involved in flavonoid synthesis, while HN stress promotes the expression of genes related to terpene skeleton production and photosynthesis. Taken together, these findings suggest that different gene expression levels under LN and HN stress contribute to the photosynthesis capacity and the accumulation of active ingredients in A. argyi leaves. Our results elucidate the physiological and molecular mechanisms of nitrogen stress on A. argyi secondary metabolites and guide fertilization strategies for plant cultivation.