Aims Licorice (Glycyrrhiza uralensis Fisch.) is a crucial medicinal herb as it accumulates glycyrrhizin and liquiritin in roots. Licorice root-associated bacterial communities shaped by soil characteristics are supposed to regulate the accumulation of root secondary metabolites. Methods The soil characteristics, root secondary metabolites, and root-associated bacterial communities were analyzed in licorice plants of different ages to explore their temporal dynamics and interaction mechanisms. Results Temporal variation in soil characteristics and root secondary metabolites was distinct. The alpha-diversity of root-associated bacterial communities decreased with root proximity, and the community composition was clustered in the rhizosphere. Different taxa that were core-enriched from the dominant taxa in the bulk soil, rhizosphere soil, and root endosphere displayed varied time–decay relationships. Soil total potassium (TK) as a key factor regulated the temporal variation in some individual taxa in the bulk and rhizosphere soils; these taxa were associated with the adjustment of root secondary metabolites across different TK levels. Conclusions Licorice specifically selects root-associated core bacteria over the course of plant development, and TK is correlated with root secondary metabolites and individual core-enriched taxa in the bulk and rhizosphere soils, which may have implications for practical licorice cultivation. Electronic supplementary material The online version of this article (10.1007/s11104-020-04692-0) contains supplementary material, which is available to authorized users.

中文翻译：

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土壤钾与不同龄期甘草根次生代谢产物及根相关核心菌的相关性


甘草（Glycyrrhiza uralensis Fisch.）是一种重要的药草，因为它在根部积累甘草甜素和甘草苷。由土壤特征形成的甘草根相关细菌群落被认为调节根次生代谢物的积累。方法分析不同龄期甘草的土壤特征、根部次生代谢产物和根部相关细菌群落，探讨其时间动态和相互作用机制。结果土壤特性和根系次生代谢产物随时间变化明显。与根相关的细菌群落的α多样性随着根的接近而降低，并且群落组成聚集在根际。从大块土壤、根际土壤和根内圈中的优势类群中核心富集的不同类群表现出不同的时间衰减关系。土壤全钾（TK）作为调节大块土壤和根际土壤中某些个体类群时间变化的关键因子；这些类群与不同 TK 水平下根次生代谢物的调整相关。结论 甘草在植物发育过程中特异性地选择与根相关的核心细菌，TK与根部次生代谢物和大体和根际土壤中的单个核心富集类群相关，这可能对实际甘草种植具有影响。电子补充材料 本文的在线版本 (10.1007/s11104-020-04692-0) 包含补充材料，可供授权用户使用。