Warming Alters Expressions of Microbial Functional Genes Important to Ecosystem Functioning

Area of Science:

• Ecology
• Microbiology
• Climate Change Science

Background:

• Soil microbial communities are crucial for ecosystem functioning.
• Climate warming is known to alter these communities, but its effects on microbial functional gene expression remain largely unknown.

Purpose of the Study:

• To investigate the impact of long-term experimental warming on the functional gene expression of soil microbial communities in a tallgrass prairie.
• To understand how warming influences carbon degradation, nutrient cycling, and overall microbial activity.

Main Methods:

• Application of the functional gene array GeoChip 3.0.
• Analysis of cDNA derived from total RNA to assess expressed genes in active soil microbial communities.
• Experimental warming treatment applied for nine years in a tallgrass prairie ecosystem.

Main Results:

• Warming significantly altered community-wide gene expression.
• Expressed genes involved in recalcitrant carbon degradation were stimulated.
• Expressed genes in phosphorus and sulfur cycling increased, suggesting accelerated processes.
• Changes in labile carbon degradation and nitrogen cycling genes varied.
• Expressed gene composition correlated with soil moisture and plant C4 leaf carbon/nitrogen content.

Conclusions:

• Warming impacts soil microbial functional gene expression, influencing carbon cycling and nutrient availability.
• Accelerated phosphorus and sulfur cycling may support increased plant growth under warming.
• RNA-based analyses can reveal long-term ecosystem responses to environmental change.