Distinct Drivers of Core and Accessory Components of Soil Microbial Community Functional Diversity under...

Area of Science:

• Soil Ecology
• Microbial Ecology
• Global Change Biology

Background:

• Soil microbial communities possess core and accessory genes, potentially influenced by different global change drivers.
• Understanding these distinct drivers is crucial for predicting ecosystem responses to environmental alterations.

Purpose of the Study:

• To investigate the differential effects of nitrogen and water addition on soil microbial core and accessory functional genes.
• To elucidate the mechanisms by which these global change factors shape microbial community structure and function.

Main Methods:

• A 5-year field experiment involving nitrogen and water addition in the Eurasian steppe.
• Quantification of microbial gene diversity using shotgun metagenomics and quantitative PCR (qPCR).

Main Results:

• Nitrogen addition significantly increased the abundance of ammonia-oxidizing bacteria and core microbial genes.
• Water addition led to a decrease in accessory gene diversity by selecting for microbes capable of degrading recalcitrant soil organic matter.
• Nitrogen addition primarily impacted core genes via nitrogen cycling, while water addition regulated accessory genes through carbon cycling.

Conclusions:

• Ecosystem nitrogen and water content are key drivers of soil microbial core and accessory functional diversity, respectively.
• Distinct global change factors have differential impacts on microbial community gene components.
• Maintaining soil organic matter is crucial for enhancing microbial functional gene diversity under global change.