Differences in carbon sequestration capacity, rhizosphere microorganisms and metabolic functions among different herbaceous plants.

Mitigating the rapid increase in global CO₂ concentrations necessitates a deeper understanding of plant-microbe symbiotic carbon sequestration. While previous research has predominantly focused on woody plants, the carbon sequestration potential and mechanisms of herbaceous plants and their rhizosphere microbiomes remain largely underexplored. To address this gap, this study employed metagenomic technology to systematically investigate the carbon sequestration capacities and metabolic mechanisms of seven plant species and their rhizosphere soil microorganisms. Plant physiological measurements were integrated with microbial functional profiles predicted via PICRUSt2. The results show that the rhizosphere soil microbial communities generally possess functional genes for carbon decomposition and carbon fixation, providing evidence for the coupling of intracellular decomposition and synthesis metabolism in microorganisms. Notably, Spearman correlation analysis established a direct statistical link between plant physiological performance and specific microbial metabolic pathways. These findings demonstrate a functional coupling between plant physiology and rhizosphere microbial carbon metabolism. By linking plant phenotypes to microbial gene pathways, this study reveals that herbaceous plants and their rhizosphere microbiomes form an integrated carbon sequestration system. Therefore, leveraging such plant-soil interactions offers a promising strategy to enhance ecosystem carbon sinks and mitigate rising atmospheric CO₂.