Linking phosphorus-solubilizing bacterial activity in uncultivated soils with soil chemical properties and key gene abundance

The concentration of soil available P is influenced by multiple processes, including the input, loss, and transformation of available P. Phosphorus limitation in terrestrial ecosystems is considered a major issue that needs to be urgently addressed for ecosystem management and restoration. Microorganisms exert important effects on soil P cycling and regulate its availability. Alkaline phosphatase (ALP), primarily derived from soil microbes, is a key enzyme responsible for hydrolyzing organic phosphorurs.
In this study, we analyzed soil samples from uncultivated land to investigate the relationships among ALP gene abundance, enzyme activity, and soil chemical properties, including total carbon, phosphorus, and nitrogen. Quantitative PCR (qPCR) was used to quantify ALP-related genes, while 16S rRNA gene sequencing was employed to characterize microbial community structure. Species richness, Shannon diversity index, and available phosphorus levels were also measured to provide ecological context.
Our findings reveal complex interactions between microbial community composition, functional gene abundance, and phosphorus availability. Notably, ALP activity did not always correspond to gene abundance—particularly phoD—suggesting the influence of regulatory mechanisms, community diversity, or environmental constraints. Furthermore, correlations between microbial diversity and ALP activity varied, underscoring the nuanced role of community structure in functional gene expression.
This integrative approach highlights the importance of combining molecular, biochemical, and ecological data to enhance our understanding of phosphorus cycling in uncultivated soils and provides valuable insight into the microbial ecology of low-disturbance terrestrial ecosystems.