Tracing priming effects in palsa peat carbon dynamics using a stable isotope-assisted metabolomics approach

作者：Christian Ayala-Ortiz, Moira Hough, Elizabeth Eder, David Hoyt, Rosalie Chu, Jason Toyoda, Steven J. Blazewicz, Patrick Crill, R. K. Varner, S. R. Saleska, Virginia I. Rich, Malak Tfaily · 发表于：Frontiers in Molecular Biosciences · 年份：2025 · DOI：10.3389/fmolb.2025.1621357 · 被引用次数：2 · 研究领域：Peatlands and Wetlands Ecology、Coastal wetland ecosystem dynamics、Soil Carbon and Nitrogen Dynamics

Introduction: Peatlands store up to a third of global soil carbon, and in high latitudes their litter inputs are increasing and changing in composition under climate change. Although litter significantly influences peatland carbon and nutrient dynamics by changing the overall lability of peatland organic matter, the physicochemical mechanisms of this impact-and thus its full scope-remain poorly understood. Methods: C Stable Isotope-Assisted Metabolomics (SIAM) to track litter carbon and its potential priming effects on both existing soil organic matter and carbon gas emissions. Through this approach, we achieved molecule-specific tracking of carbon transformations at unprecedented detail. Results: emissions, fueled nearly exclusively by transformations of litter carbon. Litter inputs significantly contributed to the organic nitrogen pool through amino acids and peptide derivatives, which served as readily accessible nutrient sources for microbial communities. We traced the fate of plant-derived polyphenols including flavonoids like rutin, finding evidence of their degradation through heterocyclic C-ring fission, while accumulation of some polyphenols suggested their role in limiting overall decomposition. The SIAM approach detected subtle molecular changes indicating minimal and transient priming activity that was undetectable through conventional gas measurements alone. This transient response was characterized by brief microbial stimulation followed by rapid return to basel...