Dongxiang wild rice rhizomicrobiomes inhibit photosynthetic methanogenic microbes: a potential solution for reducing methane emissions in northeastern China

Background Reducing greenhouse gas (GHG) emissions from agriculture is a crucial aspect of global environmental governance. In particular, reducing methane (CH₄) emissions from rice fields is a top priority for ensuring the sustainable development of agricultural ecosystems. Methane emissions from rice paddies reflect the balance between methane production and degradation, and wild rice may be an advantageous resource for modulating both processes. Results In this study, we used shotgun metagenomic sequencing, 16S rRNA analysis, and gas chromatographic determination of methane to demonstrate that methane emissions from rice paddies are significantly influenced by soil type and domestication processes. The abundances of genes related to methane metabolism were significantly lower in the wild rice rhizosphere than in the cultivated rice rhizosphere under both controlled and field conditions. Notably, we found that photoautotrophic microorganisms contributed significantly to methane production in in rice paddies. Wild rice rhizosphere suspension validation tests confirmed that the rich and diverse microbial resources in the wild rice rhizosphere effectively inhibited photoautotrophic methanogens to reduce methane emissions from cultivated rice. Conclusions On the basis of our results, we propose that harnessing the rhizosphere microbial strain resources of wild rice is a novel and feasible strategy for reducing global GHG emissions in black soil rice agriculture. This approach could make a significant contribution towards achieving the "carbon peak and carbon neutrality" goals.