Year-end Sale % OFF 
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.
Highlights
Biodiversity is hypothesized to underpin ecosystem functioning (Balvanera et al, 2006; Lefcheck et al, 2015; Tilman, 1999) and whether biodiversity supports ecosystem productivity is a major area of research in ecology (Gross et al, 2014; Naeem and Li, 1997; Tilman et al, 2006)
Apart from the overall bacterial community, we focused on the N-cycling microbial communities performing nitrification and denitrification that are responsible for N losses by leaching or nitroge nous gas emissions, including the greenhouse gas nitrous oxide (N2O)
Our results showed that the reduction of microbial di versity in the bulk soil constrained plant microbiome selection, and only Alphaproteobacteria and Bacteroidetes were enriched in the barley compartments irrespective of dilution level
Summary
Biodiversity is hypothesized to underpin ecosystem functioning (Balvanera et al, 2006; Lefcheck et al, 2015; Tilman, 1999) and whether biodiversity supports ecosystem productivity is a major area of research in ecology (Gross et al, 2014; Naeem and Li, 1997; Tilman et al, 2006). Either directly or indirectly, the microbial communities surrounding the roots (Bulgarelli et al, 2013; Hu et al, 2018; Schulz-Bohm et al, 2018; Zhalnina et al, 2018). This results in the differential enrichment of taxa in the rhizosphere and the rootassociated compartments compared to the bulk soil (Lundberg et al, 2012). On and in proximity to root tissues are impacting plant growth and health, it has been proposed that the plant and its microbiota collectively form a holobiont
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
