Specificity in Arabidopsis thaliana recruitment of root fungal communities from soil and rhizosphere

Abstract

Biotic and abiotic conditions in soil pose major constraints on growth and reproductive success of plants. Fungi are important agents in plant soil interactions but the belowground mycobiota associated with plants remains poorly understood. We grew one genotype each from Sweden and Italy of the widely-studied plant model Arabidopsis thaliana. Plants were grown under controlled conditions in organic topsoil local to the Swedish genotype, and harvested after ten weeks. Total DNA was extracted from three belowground compartments: endosphere (sonicated roots), rhizosphere and bulk soil, and fungal communities were characterized from each by amplification and sequencing of the fungal barcode region ITS2. Fungal species diversity was found to decrease from bulk soil to rhizosphere to endosphere. A significant effect of plant genotype on fungal community composition was detected only in the endosphere compartment. Despite A. thaliana being a non-mycorrhizal plant, it hosts a number of known mycorrhiza fungi in its endosphere compartment, which is also colonized by endophytic, pathogenic and saprotrophic fungi. Species in the Archaeorhizomycetes were most abundant in rhizosphere samples suggesting an adaptation to environments with high nutrient turnover for some of these species. We conclude that A. thaliana endosphere fungal communities represent a selected subset of fungi recruited from soil and that plant genotype has small but significant quantitative and qualitative effects on these communities.

Priority Actions to Improve Provenance Decision-Making

“…Populations are often locally adapted (Leimu and Fischer 2008, Hereford 2009, Oduor et al 2016. Local adaptation can have both climate and many nonclimate components, including other abiotic factors such as soil and photoperiod (Savolainen et al 2013, Christmas et al 2016a, but biotic factors such as antagonists and mutualists are also important (Crémieux et al 2008, Gellie et al 2016, Gehring et al 2017, Urbina et al 2018. Some nonlocal provenances may have no history of exposure to local pests and pathogens (Potts et al 2016), and pests and pathogens may themselves be shifting their ranges (Burke et al 2017), potentially increasing the risk of maladaptation (Gellie et al 2016).…”

“…However, there are largely unappreciated extended effects of provenance choice on organisms that colonize and inhabit restoration plantings (Whitham et al 2006, Crémieux et al 2008, Bucharova 2017). Provenance effects have been shown to affect individual organism responses, as well as biotic communities both above- (Bucharova et al 2016, Gosney et al 2017) and belowground (Senior et al 2016, Gehring et al 2017, Urbina et al 2018. The coevolutionary relationships between local provenances and their dependent communities (e.g., Toju andSota 2005, Gehring et al 2017) further emphasize the importance of considering the extended effects of using local or nonlocal provenances on ecological networks.…”

Walking Ecosystems in Microbiome-Inspired Green Infrastructure: An Ecological Perspective on Enhancing Personal and Planetary Health

“…Microbial diversity is a key driving factor in maintaining favorable plant health [94,95]. Indeed, individual plant genotypes can show distinct microbial diversity, which indicates that some plants have the ability to cultivate a beneficial microbiome and this process may be under natural selection [96]. Therefore, strategies to enhance microbial diversity to benefit human health also have the potential to generate important co-benefits for plants, with cascading benefits to the wider ecosystem.…”

Soil microbes alter plant fitness under competition and drought

“…Thus, heterogeneity in local environmental conditions and soil microbiota should generate diversity in the associated‐microbial restructuring strategies among plant populations. Combining detailed characterization of both plant phenotypes and associated soil microbial communities from natural systems with manipulative studies is required to fully understand the role of soil microbes in plant evolution (Baltrus, ; Castrillo et al., ; Urbina et al., ).…”