Comparison between wild and related cultivated rice species reveals strong impacts of crop domestication on methane metabolism of the rhizomicrobiome

Abstract Background Rice root-inhabited microbial communities are seriously affected by domestication as evidenced by comparing the rhizomicrobiomes of wild and related cultivated rice species. While earlier studies focused on the structures of the rhizomicrobiomes, here, we compared the functioning of the microbial communities in the rhizosphere of wild versus that of related cultivated rice species, which were originated from Africa and Asia. Results The microbial functions involved in carbon metabolism and nucleotide metabolism were found to be enriched in wild rice species, whereas those involved in nitrogen metabolism, lipid metabolism, metabolism of cofactors and vitamins, and xenobiotic biodegradation were more enriched in cultivated rice species. Among the overall carbon metabolism, specifically, methane metabolism of the rhizomicrobiomes clearly differed between wild and cultivated rice. The key enzymes in methane production and utilization were overrepresented in wild rice species, suggesting that the rhizomicrobiome of wild rice maintained a better ecological balance for methane production and utilization than the related cultivated rice species. Conclusions For the first time, the impacts of rice domestication on the main metabolic pathways of the rhizomicrobiome were assessed, which revealed the strong impacts of rice domestication on methane metabolism that is one of the most critical functions of the microbial community of the rhizosphere of rice. The results provide important guidelines for future breeding and cultivation of rice in the framework of more sustainable rice production.