The priming effect, leading to the net increase in the heterotrophic decomposition of refractory organic carbon in the presence of highly reactive organic carbon. The priming effect has been widely recognized as a potential removal pathway for refractory organic carbon in the ocean, but further studies on the transformation process of refractory molecules are still needed. In this study, we conducted incubation experiments with deep sea water from the Western Pacific. A combination of liquid chromatography-mass spectrometry (LC-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to study the changes associated with the priming effect, with a particular focus on the consumption and transformation process of refractory DOM. Our research combines information on microbial community composition and abundance to identify key microorganisms and their contribution to DOM transformation. Using integrated metabolomics methods, we analyzed the metabolism of refractory DOM under priming effect, identifying structural features of transformable molecules. This study provides new insights into the metabolic basis of the initiation effect, especially in the context of DOM dynamics that linked with priming effect.

Priming effect,DOM,LC-MS,FT-ICR MS,Refractory DOM