Change in underground microbiome of Adenophora triphylla farmland after continuous cropping

Adenophora triphylla is a widely used medicinal herb in East Asia, valued for its pharmacological properties , with its shoots and young leaves also consumed as a vegetable. Unlike many plants, A. triphylla minimal disease incidence despite long-term continuous cropping. However, study on this phenomenon is limited, and the underlying mechanisms remain unclear. In this study, we examined the microbiome of A. triphylla farmland after continuous cropping for 3-4, 4-5, 5-6, and 7-8 years. Soil and root samples were collected from these fields, and bacterial and fungal microbiomes were analyzed using the Illumina MiSeq platform. Our results revealed that fungal microbiomes were more dramatically changed than that of bacterial microbiome, both spatially and temporally. While bacterial communities remained relatively stable in both soil and root, fungal communities exhibited distinct changes. In roots, major fungal genera were predominantly plant pathogens, whereas soil fungal microbiome were dominated by saprotrophs, with little overlap in relative abundance between root and soil communities. In both samples, the component of major genera exhibited constant changes in their abundance. These findings suggest that the resilience of A. triphylla to continuous cropping stress may be linked to the stable bacterial communities in underground. Further studies are necessary to elucidate the precise mechanisms underlying the absence of continuous cropping obstacles in A. triphylla. Understanding these interactions may provide valuable insights into sustainable plant cultivation.