Regulation of soil nutrient cycling in the root zone of Pyracantha fortuneana: The role of core microbiome induced by plant species

Background

A host-plant and its associated microbiota are interdependent, with the enduring root zone microbial communities evolving over an extended period for a specific plant species. However, the long-term stability and functioning of host-associated microbiota, and their potential to be influenced by introduced plants, remain poorly understood.

Aims

Our objective was to ascertain the relative contributions of core and rare microbiota in maintaining community stability and soil nutrient cycling in the presence of introduced plants.

Methods

We executed a pot experiment where four plant species at varying successional stages were planted in soil collected from the root area of Pyracantha fortuneana. Soil samples were collected 2 years post-planting. The soil nutrients, enzyme activities, and microbial networks under different introduced plants were analyzed.

Results

The growth of Betula luminifera significantly enhanced soil enzyme activity, multi-nutrient cycling level, and microbial community diversity, compared to soils cultivated with Imperata cylindrica and Zanthoxylum simulans. Furthermore, the treatment involving B. luminifera planting exhibited a lower clustering coefficient and higher average path length than other treatments. Core taxa demonstrated higher node degree and betweenness centrality than rare taxa, favoring the stability of the microbial network. Importantly, the core taxa, particularly their co-occurrence network properties, were the primary drivers for multi-nutrient cycles of P. fortuneana root zone soils. Among the core taxa, Mortierellomycetes, Dothideomycetes, Thermoleophili, and Rubrobacteria were abundant in the treatment involving B. luminifera and were significantly positively correlated with most soil nutrient extracellular enzymes, thereby contributing to soil multi-nutrient cycling.

Conclusion

Core taxa significantly influence the microbial stability in the root zone soil of P. fortuneana. The introduction of B. luminifera can enhance the stability of the microbial community structure within this soil, thereby promoting soil nutrient cycles.