3.5. Co-occurrence of Bathyarchaeia with soil microorganisms
Co-occurrence network analysis was performed to determine the interactions of Bathyarchaeia with other archaea to examine the potential ecological functions of Bathyarchaeia in paddy soils.Bathyarchaeia mainly co-occurred with the members ofNitrososphaeria , Methanosarcinia, andMethanobacteria (Fig. 6d). The co-occurred ASVs were selected to establish a phylogenetic tree (Fig. S5). The phylogenetic tree indicated that the co-occurrence archaea have various potential metabolisms (Fig. S5). Some co-occurrence archaea belonging to methanogens can use acetate and H2/CO2 to produce methane. The Zi-Pi plot indicated that Bathyarchaeia and Nitrososphaeriaincluded keystone “species” (Fig. 6b). The keystone ASVs were ASV 1790 (Bathyarchaeia ), ASV 2007 (Bathy-6 ), ASV 1248 (Nitrososphaeria ), indicating their crucial role in maintaining the stability of microbial community structure. ASVs belonging toBathyarchaeia were selected to establish the network (Fig. 6e).Bathyarchaeia and Bathy-6 were divided into different modules. Different modules showed significant correlations with other environmental parameters, indicating a high diversity withinBathyarchaeia and Bathy-6 in paddy soils (Fig. 6f). Niche overlap was evaluated to explore the interaction betweenBathyarchaeia and other archaea. Bathyarchaeia showed a higher niche overlap with archaea, whereas Nitrososphaeria showed a lower niche overlap with archaea (Table S2).