Effect of plant species and soil depth on comammox Nitrospira in a coastal wetland

Plant species could play a crucial role in mediating the activity and community structure of soil microorganisms through litter and rhizosphere inputs. However, we currently have a poor understanding of the influence of plant species on the newly discovered comammox Nitrospira, and if this effect is simultaneously regulated by soil depths. Here, we investigate the diversity and community structure of comammox Nitrospira in three soil depths from five different plant species and a bare tidal flat in a subtropical estuarine wetland. Plant species played a critical role in driving the niche differentiation of individual clades of comammox Nitrospira, explaining 59.3% of the variation of community structure. Total nitrogen (TN), total carbon (TC) and salinity were the top three environmental factors influencing the community structure of comammox Nitrospira. Together, our results highlight the previously unrecognized critical role of plant species in driving the niche differentiation of comammox Nitrospira community structure in a subtropical estuarine wetland.