Water deficit affects inter‐kingdom microbial connections in plant rhizosphere

Abstract

The frequency and severity of drought are increasing due to anthropogenic climate change and are already limiting cropping system productivity in many regions around the world. Few microbial groups within plant microbiomes can potentially contribute towards the fitness and productivity of their hosts under abiotic stress events including water deficits. However, microbial communities are complex and integrative work considering the multiple co-existing groups of organisms is needed to better understand how the entire microbiome responds to environmental stresses. We hypothesize that water deficit stress will differentially shape bacterial, fungal, and protistan microbiome composition and influence interkingdom microbial interactions in the rhizospheres of corn and sugar beet. We used amplicon sequencing to profile bacterial, fungal, and protistan communities in corn and sugar beet rhizospheres grown under irrigated and water deficit conditions. The water deficit treatment had a stronger influence than host species on bacterial composition, whereas the opposite was true for protists. These results indicate that different microbial kingdoms have variable responses to environmental stress and host factors. Water deficit also influenced intra-and inter-kingdom microbial associations, wherein the protist taxa formed a separate cluster under water deficit conditions. Our findings help elucidate the influence of environmental and host drivers of bacterial, fungal, and protistan community assembly and co-occurrence in agricultural rhizosphere environments.

Comparative metagenomic analysis reveals rhizosphere microbial community composition and functions help protect grapevines against salt stress

“…Plant cultivars are known to have a strong influence on rhizobacterial networks and keystone species ( Jiang et al, 2017 ). Moreover, a previous study reported that water deficit changed the stability of plant rhizosphere networks ( Bazany et al, 2022 ). In the current study, the microbial co-occurrence network of 101-14 was more complex than that of 5BB under salt stress.…”

Drought-induced recruitment of specific root-associated bacteria enhances adaptation of alfalfa to drought stress

“…The interaction between plants and the soil microbiomes that colonize the rhizosphere and root system is considered a key factor in the rapid adaptation of plants to soil environmental stress (Pascale et al, 2019). However, changes in the rhizosphere microbial community under drought stress depend on the influence of the host plant and the surrounding soil (Bazany et al, 2022). Differences in plant varieties (genotypes) can lead to different levels of drought tolerance.…”

Understanding the sugar beet holobiont for sustainable agriculture

“…The archaeal family Nitrososphaeraceae is steadily represented but derived from soil (Wolfgang et al, 2020 ). Protists play a pivotal role in shaping sugar beet rhizosphere microbiomes (Bazany et al, 2022 ), but are rarely investigated on metagenomic levels. Interestingly, sugar beet rhizospheres were repeatedly reported to display a comparable (Mendes et al, 2011 ), or even higher bacterial alpha diversity than surrounding bulk soil in the early seedling stages (Zachow et al, 2014 ; Wolfgang et al, 2020 ), but also in the rhizosphere of pre-harvest taproots (Cardinale et al, 2020 ), while also significant lower rhizosphere alpha diversity compared to bulk soil was reported (Cui et al, 2022 ).…”