Biogeography and niche differentiation of Bathyarchaeia in paddy soils across eastern China

Bathyarchaeia (formerly Bathyarchaeota) is a group of highly abundant archaeal communities that play important roles in global biogeochemical cycling. The presence of Bathyarchaeia in arable soils is relatively limited. In this study, we aimed to investigate the spatial distributions and diversity of Bathyarchaeia in paddy soils across eastern China, which is a major rice production region. The relative abundance of Bathyarchaeia among total archaea ranged from 3% to 68%, and Bathy-6 was the dominant subgroup. Bathyarchaeia showed higher migration ability and wider niche. Soil pH and C/N ratio were identified as key factors influencing the Bathyarchaeia composition, whereas C/N ratio and mean annual temperature influenced the relative abundance of Bathyarchaeia. Network analysis showed that specific Bathyarchaeia taxa occupied keystone positions in the archaeal community and co-occurred with some methanogenic and ammonia-oxidizing archaea. This study provides important insights into the biogeography and niche differentiation of Bathyarchaeia in agroecosystems.