Collembolans maintain a core microbiome responding to diverse soil ecosystems

The unique gut habitat led to a core intestinal microbiome in diverse soil ecosystems.The collembolan guts may help eliminate soil pathogens.Host-selection carried more weight on community assembly of gut microbiome.Soil invertebrates are widely distributed in the ecosystem and are essential for soil ecological processes. Invertebrate gut microbiome plays an important role in host health and has been considered as a hidden microbial repository. However, little is known about how gut microbiome in soil invertebrates respond to diverse soil ecosystems. Based on a laboratory microcosm experiment, we characterized the assembling of microbiome of soil collembolans (Folsomia candida) from six representative regions of the soil ecosystem which they inhabit. Results showed that collembolan gut microbial communities differed significantly from their surrounding soil microbial communities. A dominant core gut microbiome was identified in gut habitat. Community analyses indicated that deterministic process dominated in the community assembly of collembolan gut microbiome. The results further demonstrate a dominant contribution of host selection in shaping gut microbiome. It is also worthy to mention that pathogens, such as common agricultural phytopathogenic fungi Fusarium, were involved in core microbiome, indicating that collembolans could act as vectors of pathogens. Our results unravelled the existence of gut core microbiome of collembolans in soil ecosystems and provided new insights for understanding the crucial role of gut microbiome of soil fauna in maintaining microbial biodiversity and stability of soil ecosystems.