Soil microbiome and metabolome analysis reveals beneficial effects of ginseng–celandine rotation on the rhizosphere soil of ginseng-used fields

Abstract

Ginseng (Panax ginseng C.A.Meyer) cultivation is hindered by the continuous cropping obstacle, whereby without appropriate rotations yield decline and fields must be abandoned. Organism interactions in the rhizosphere alleviate and improve the obstacles to continuous cropping of ginseng. In this study, high-throughput sequencing and gas chromatography coupled with time-of-flight mass spectrometry (GC–TOF-MS) in combination with analysis of soil chemical properties were used to investigate soil microecological changes after 5 years of celandine (Chelidonium majus L.) cultivation in land previously planted with ginseng for 6 years. Comparison of data for the ginseng–celandine rotation (experimental group) and ginseng–fallow (control group) revealed that the celandine rhizosphere TOC, AN, and AK contents as well as PPO activity and Cat activity were significantly increased. Rotation increased the abundance of some bacteria and fungal in the rhizosphere of celandine rhizosphere soil, such as Arthrobacter, Metarhizium, and Exophiala. The relative abundance of Fusarium in ginseng–celandine rotation soil was lower than that of ginseng–fallow soil, which may effectively reduce the incidence of ginseng root rot. The non-targeted metabolites and microbial community structure of the rhizosphere soil were changed with celandine cultivation. In celandine rhizosphere soil, the abundance of the bacterial and fungal communities was positively or negatively correlated with rhizosphere soil metabolites. Pathway enrichment analysis showed that starch and sucrose metabolism were significantly enriched in the celandine rhizosphere soil, a result consistent with the results shown in bacterial community function prediction and non-targeted metabolomics. The present combined analysis of the soil microbiome and non-targeted metabolome provided insight into the effects and mechanism of ginseng–celandine rotation on the soil micro-ecosystem of ginseng-used fields. Briefly, crop rotation with celandine was beneficial to soil quality, and it is a good option to alleviate Ginseng continuous cropping obstacles.