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Research article - Peer-reviewed, 2022

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

Graf, Daniel R. H.; Jones, Christopher M.; Zhao, Ming; Hallin, Sara

Abstract

The rhizosphere is a hotspot for denitrification. The nitrous oxide (N₂O) reductase among denitrifiers and nondenitrifying N₂O reducers is the only known N₂O sink in the biosphere. We hypothesized that the composition of root-associated N₂O-reducing communities when establishing on annual crops depend on soil type and plant species, but that assembly processes are independent of these factors and differ between nosZ clades I and II. Using a pot experiment with barley and sunflower and two soils, we analyzed the abundance, composition, and diversity of soil and root-associated N₂O reducing communities by qPCR and amplicon sequencing of nosZ. Clade I was more abundant on roots compared to soil, while clade II showed the opposite. In barley, this pattern coincided with N₂O availability, determined as potential N₂O production rates, but for sunflower no N₂O production was detected in the root compartment. Root and soil nosZ communities differed in composition and phylogeny-based community analyses indicated that assembly of root-associated N₂O reducers was driven by the interaction between plant and soil type, with inferred competition being more influential than habitat selection. Selection between clades I and II in the root/soil interface is suggested, which may have functional consequences since most clade I microorganisms can produce N₂O.

Keywords

denitrification; nitrous oxide; rhizosphere; soil

Published in

FEMS Microbiology Ecology
2022, volume: 98, number: 9
Publisher: OXFORD UNIV PRESS

Authors' information

Graf, Daniel (Graf, Daniel )
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Zhao, Enid Ming
Swedish University of Agricultural Sciences, Department of Plant Biology
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology

UKÄ Subject classification

Microbiology

Publication Identifiers

DOI: https://doi.org/10.1093/femsec/fiac092

URI (permanent link to this page)

https://res.slu.se/id/publ/118790