Comparison of network connectivity and environmental driving factors of root-associated fungal communities of desert ephemeral plants in two habitat soils

Abstract

Root-associated microorganisms regulate plant growth and development, and their distribution is likely influenced by habitat conditions. In this study, the responses of rhizosphere and root-endophytic fungi of dominant ephemeral plants to aeolian soil (AS) and grey desert soil (DS) in the Gurbantünggüt Desert were analyzed using high-throughput sequencing. This was done to understand the adaptation strategies of this vegetation in typical habitat soils from a microbial perspective. We found that the diversity of root-associated fungi of ephemeral plants differed in the two habitat soils. The diversity of rhizosphere fungi was relatively low in AS compared to DS, whereas the diversity of root-endophytic fungi was higher in AS. The community structure of root-associated fungi and relative abundances of some dominant taxa differed between the two soils. A co-occurrence network showed that the degree of coupling and interaction between root-associated fungal taxa were closer in AS than in DS and that most of the fungal taxa were cooperative in the two habitat soils. Additionally, the network properties of the root-endophytic fungi were apparent different between the two soils. Environmental factors, including electrical conductivity, soil organic carbon, carbon/nitrogen, and carbon/phosphorus ratios, were found to be key factors affecting rhizosphere fungi in DS, whereas soil available phosphorus was the main factor in AS. Several factors affect the root-endophytic fungal community and are more influential in DS than in AS. Overall, the root-associated fungal communities of ephemeral plants had different adaptation strategies to the two soils: increasing the diversity of rhizosphere fungi and their relationship with environmental factors in DS, and increasing the diversity and network relationships of root-endophytic fungi in AS. These findings provide insight into the assemblage of ephemeral plant root-associated microbial communities and the underlying environmental factors, which allows for a deeper understanding of how to construct an artificial core root microbiota to promote plant growth and resistance.