Rhizosphere microbiome assemblage impacts soil chemical properties and medicinal quality in Atractylodes chinensis

Geographic variation markedly influences Atractylodes chinensis medicinal quality, driven by rhizosphere processes regulating atractylodin accumulation. Understanding soil-microbe-phytochemical interactions is essential for targeted cultivation to stabilize bioactive compound content.

This study investigated the relationships among rhizosphere soil properties, microbial communities, and atractylodin content in A. chinensis from three geographic origins including high-content (HC; E118°48'55″, N41°21'40″), medium-content (MC; E115°31'30″, N40°29'36″), and low-content (LC; E117°40'22″, N41°20'24″). Analyses encompassed soil chemical properties (nutrients, trace elements), enzyme activities, and the composition of bacterial and fungal communities, alongside their correlations with atractylodin accumulation.

Significant inter-regional differences in soil properties were observed. MC soils exhibited the highest levels of organic matter, total nitrogen, and hydrolyzable nitrogen. LC soils contained elevated concentrations of trace elements (Zn, Cu, Fe, Mn) and total potassium. In contrast, HC soils possessed the highest magnesium content. Activities of soil phosphatases (alkaline phosphatase and neutral phosphatase) also differed significantly among sites. Microbial α-diversity peaked in MC soils. Distinct β-diversity patterns clearly differentiated the microbial communities of all three regions. In addition, bacterial community composition showed a stronger association with soil chemical parameters than fungal communities. The relative abundances of Methylomirabilota (bacteria) and Mortierellomycota (fungi) correlated positively with atractylodin content, whereas Actinobacteriota (bacteria) abundance correlated negatively.

These findings elucidate key ecological mechanisms driving variation in the medicinal quality of A. chinensis and provide practical insights for optimizing cultivation practices, including soil management and cultivar selection, to standardize quality and enhance stability of its medicinal value.