Lucerne (Medicago sativa) alters N2O-reducing communities associated with cocksfoot (Dactylis glomerata) roots and promotes N2O production in intercropping in a greenhouse experiment

Assembly of root-associated N2O-reducing communities of annual crops is governed by selection for nosZ clade I over clade II

“…Differences in organic C and N also likely contribute to the uniqueness of N 2 O reducing communities in each soil type, with potentially higher availability of these resources in the clayey soil. The overriding effect of soil type is in line with what is known for microbial community structure in general in the root–soil continuum for different plant species (Berg and Smalla 2009 , Bulgarelli et al 2012 , Lundberg et al 2012 , Edwards et al 2015 , Prasse et al 2015 ) and recently reported also for nosZ I and nosZ II communities under cultivation of lucerne and cocksfoot (Graf et al 2019 ). The root-associated N 2 O reducing communities were more variable in structure than those of the soil communities within each sample type, which could be an effect of subsampling the entire root system that comprises multiple niches and microbiomes (e.g.…”

“…Denitrification is stimulated by plant-derived organic carbon and fluctuating levels of oxygen availability in the root compartment (Henry et al 2008 , Philippot et al 2009 ), and a higher proportion of denitrifiers relative to other heterotrophic bacteria is generally detected in proximity to roots (Hamonts et al 2013 ). Recent work suggests that microorganisms or consortia of microorganisms capable of complete denitrification with enzymatic reduction of N 2 O to N 2 by the N 2 O reductase are selected for or stimulated around roots (Langarica-Fuentes et al 2018 , Graf et al 2019 , Ai et al 2020 ).…”

Neglected Dissimilatory Nitrate Reduction to Ammonium Pathway of Nitrate Reduction in the Chinese Marginal Sea and Its Microbial Community Assembly Driven by Stochastic Processes

“…Therefore, the enhancement of DNRA process in nutrient-poor marine systems facilitates the retention of ammonium to improve the primary productivity as well as reduce N 2 O emissions. 60 The results of this study may provide valuable information for the management and environmental effects of marine nitrate pollution.…”

Carbon Substrate Selects for Different Lineages of N2O Reducing Communities in Soils Under Anoxic Conditions

“…Several studies indicate that organisms with nosZ clade II are important for mitigating N 2 O emissions in arable soils (Jones et al, 2014;Domeignoz-Horta et al, 2016;Xu et al, 2020), although organisms with clade I nosZ associated with the roots of leguminous plants have also been shown to be potentially important N 2 O sinks (Sameshima-Saito et al, 2006;Gao et al, 2021). Comparisons of the abundance and diversity of both nosZ groups over gradients of various edaphic factors, as well as between rhizosphere and bulk soil environments suggest niche partitioning between organisms with nosZ clade I and II, which may have a significant effect on net N 2 O emissions (Jones et al, 2014;Tsiknia et al, 2015;Juhanson et al, 2017;Graf et al, 2019;Assémien et al, 2019;Shi et al, 2021). Although the overall availability of carbon (C) substrates is one of the key factors regulating denitrification rates as well as affecting the composition of denitrifying communities in soil (Wallenstein et al, 2006), the effect of different C substrates on the community composition, diversity and abundance of N 2 O reducing microorganisms in soil is poorly understood.…”