Variations in microbial functional potential associated with phosphorus and sulfur cycling in biological soil crusts of different ages at the Tengger Desert, China

Abstract Microbial communities play a very important role in soil ecological processes by regulating biogeochemical cycles during biological soil crust (BSC) succession in desert ecosystems. Although the relationships between microbial carbon or nitrogen and the BSC at different successional stages have been a source of great concern, there are few reports regarding the phosphorus (P) and sulfur (S) cycles. In this study, we used a functional gene array (GeoChip 5.0) to analyze the characteristics of microbial communities and their functional genes involved in the P and S cycles along a chronosequence of BSC succession in the Tengger Desert, China. The results showed that the functional genes associated with polyphosphate degradation and sulfite reduction were the major components involved in the P and S cycles, respectively, and the intensities of the functional genes expression involved in the P and S cycles increased significantly in 61-year-old BSCs. Compared with the fungal and archaeal communities, the bacterial community was the major contributor to the P and S cycles, and Proteobacteria (mainly Alphaproteobacteria, Gammaproteobacteria, and Betaproteobacteria) and Actinobacteria were the dominant phyla. A redundancy analysis showed that there was significant synergy between the improvement in soil properties (e.g., soil nutrient content) and the intensities of genes expression related to P and S cycles. These findings indicated that after 61 years, BSC significantly promoted the microbial metabolic potential for P and S cycling, which in turn promoted soil rehabilitation in a desertified dryland.