Positive response of host root-associated bacterial community and soil nutrients to inhibitory parasitism of dodder

Purpose Parasitic plants are important drivers of plant communities and even ecosystems through parasitic plant-host interactions, but little is known about parasitism effects on host belowground soil resources and microbial communities. Methods We investigated the soil nutrients and the root-associated (root zone, rhizosphere, root endosphere and root nodule) bacterial communities of soybean ( Glycine max ) with different parasitism statuses (noninhibitory and inhibitory interactions) induced by plant dodder ( Cuscuta chinensis ) in soils from three different origins. Results Our results showed that inhibitory parasitism, rather than noninhibitory parasitism, significantly promoted soil multinutrient accumulation in the soybean root zone. Parasitism, especially inhibitory parasitism, increased the bacterial enrichment in the closely root-associated compartments (rhizosphere, root endosphere and root nodule) of soybean, including the rhizobial taxa. Additionally, the closely root-associated bacterial communities of soybean with inhibitory parasitism had higher soil environmental sensitivity than that of other soybeans, especially the nodule community to soil nitrate nitrogen. Network analysis indicated that inhibitory parasitism led to higher complexity and instability of the closely root-associated bacterial communities. Structural equation model showed that the effects of root zone community and key soil factor on the positive associations of the closely root-associated bacterial communities varied with parasitism status. Conclusions These results provide important perspectives for understanding the effects of parasitic plant-host interactions on the dynamics of host belowground microbial communities and soil nutrient cycling in agricultural and natural ecosystems.