Abstract

Plant roots are shaping microbial communities that are distinct from the surrounding soil. These root-associated microbial communities can have both positive and negative effects on the host nutrient acquisition and thereby growth, yet how loss of soil microbial diversity will constrain the plant microbiome selection is relatively unknown. In this study, we manipulated the soil microbial community using a removal-by-dilution approach to examine how microbial diversity modulates microbiome selection in barley, including microbial guilds involved in nitrogen (N) cycling processes causing N loss, and its consequences for plant performance. We found that microbial diversity loss reduced the barley's ability to recruit specific microorganisms from the soil and only members of the Alphaproteobacteria and Bacteroidetes were enriched in both rhizosphere and root-associated compartments irrespective of dilution level. Loss in soil microbial diversity and the presence of plants affected the N-cycling communities, with the abundance of nitrous oxide reducers being 2-4 times higher in both barley compartments in the lower diversity soils. In these soils, the low abundance of bacterial ammonia oxidizers (close or below detection level in the barley compartments) was concomitant with an increase in leaf greenness (ca. 12%), an indicator of the plant N status. The reduction in soil microbial diversity was thus coupled to a change in functional traits of rhizosphere and root-associated communities, with consequences for plant performance. This work contributes to our understanding of plant-microbe interactions, which is needed to steer the crop microbiome towards increased N-use efficiency while minimizing negative environmental impact.

Keywords

Dilution; Bacterial community; Plant microbiome; ammonia oxidation; Denitrification; Nitrogen

Published in

Applied Soil Ecology
2022, Volume: 169, article number: 104224
Publisher: ELSEVIER

SLU Authors

• Saghai, Aurélien

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Wittorf, Lea

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Hallin, Sara

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Soil Science
Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.apsoil.2021.104224

Permanent link to this page (URI)

https://res.slu.se/id/publ/113952