Cernava, T. | bioRxiv Science

bioRxiv2024

Biological management, rather than chemical management, promotes the interaction between plants and their microbiome

In the face of climate change, developing sustainable agricultural practices to reduce the use of synthetic herbicides and pesticides is crucial. However, breeding for higher yields can lead to the decoupling of plant roots and beneficial rhizosphere microbes. In this study, we aim to identify potato cultivars with functional traits facilitating efficient interactions with the rhizosphere microbiome under various agricultural treatments in the field. With the results of profiling microbial communities with amplicon sequencing data of bacteria (16S rRNA gene fragments) and fungi (ITS2 region), a piecewise structural equation model was developed. This model explains the trade-off effects of agricultural management and potato cultivars on plant growth by affecting the rhizosphere microbiome. Furthermore, we highlight that plant cultivar and the rhizosphere microbiome together determine plant below-ground growth under biological management. In contrast, both components are found to be uncoupled under chemical and control management. Our study reveals the importance of considering microbiomes in the breeding process to achieve the goals of sustainable agriculture.

microbiology↗

bioRxiv2019

Unravelling native plant resistomes - The Sphagnum microbiome harbours versatile and novel antimicrobial resistance genes

The expanding antibiotic resistance crisis calls for a more in depth understanding of the importance of antimicrobial resistance genes (ARGs) in pristine environments. We, therefore, studied the microbiota associated with Sphagnum forming the main vegetation in undomesticated, evolutionary old bog ecosystems. In our complementary analysis of a culture collection, metagenomic data and a fosmid library, we identified a low abundant but highly diverse pool of resistance determinants, which targets an unexpected broad range of antibiotics including natural and synthetic compounds. This derives both, from the extraordinarily high abundance of efflux pumps (80%), and the unexpectedly versatile set of ARGs underlying all major resistance mechanisms. The overall target spectrum of detected resistance determinants spans 21 antibiotic classes, whereby {beta}-lactamases and vancomycin resistance appeared as the predominant resistances in all screenings. Multi-resistance was frequently observed among bacterial isolates, e.g. in Serratia, Pandorea, Paraburkhotderia and Rouxiella. In a search for novel ARGs we identified the new class A {beta}-lactamase Mm3. The native Sphagnum resistome comprising a highly diversified and partially novel set of ARGs contributes to the bog ecosystems plasticity. Our results shed light onto the antibiotic resistance background of non-agricultural plants and highlight the ecological link between natural and clinically relevant resistomes.

microbiology↗