Host species identity in annual Brassicaceae has a limited effect on the assembly of root-endophytic fungal communities

ABSTRACT

Background

Establishing the contribution of host plant genotype to the assembly of root-associated microbial communities can be challenging, since multiple ecological factors may confound the effects purely due to the host, and plant species often do not occur sympatrically.

Aims

We aimed to measure the relative importance of host plant species on driving the assembly of natural root-endophytic fungal communities, as compared to other habitat conditions that depend on the local environment.

Methods

Species of annual wild Brassicaceae and the cultivated Brassica napus were collected in two separate locations, where they grew in close proximity. Arrhentherum elatius (Poaceae) was also collected in both sites and used as outgroup. The root-endophytic fungal communities of these plants were characterised using Illumina MiSeq amplicon sequencing and cultivation, and compared between locations and hosts.

Results

Plant family and sampling location were the factors driving most variation in fungal communities, affecting both community composition and the proportion of cultivable fungi. Whether Brassicaceae were wild or domesticated had little effect on endophytic communities, although its contribution increased when cultivable fungi were considered. No strong specificity of endophytes towards hosts was found, because a core mycobiome was shared by different species.

Conclusions

Plant species is a limited predictor of the structure and composition of fungal endophytic communities in roots of annual Brassicaceae, as compared to geographic location. However, the host effect on endophytic assemblages increases with phylogenetic distance between hosts.

KEYWORDS:

• Brassicaceae
• endophytes
• fungi
• host specificity
• roots

Acknowledgements

We are grateful to landowners for allowing samplings on their property. This study was supported by LOEWE (Landes-Offensive zur Entwicklung Wissenschaftlich-ökonomischer Exzellenz) of the state of Hesse and was conducted within the framework of the Cluster for Integrative Fungal Research (IPF).

Author contributions

K.G., M.T. and J.G.M.-V. designed the study; K.G. and J.G.M.-V. performed the samplings; K.G. conducted the research; M.T. and J.G.M.-V. contributed reagents and analytical tools; J.G.M.-V. analysed the data with assistance from K.G.; J.G.M.-V. drafted the manuscript; and all authors contributed to the last version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Landes-Offensive zur Entwicklung Wissenschaftlich-ökonomischer Exzellenz (LOEWE) [Integrative Fungal Research (IPF)].

Notes on contributors

Kyriaki Glynou

Kyriaki Glynou is interested in the ecology and biogeography of root-associated fungi.

Marco Thines

Marco Thines is interested in all aspects of the evolution of plants with their mutualists and pathogens.

Jose G. Maciá-Vicente

Jose G. Maciá-Vicente studies fungal ecology, with a main interest in the interactions and evolution of plant-symbiotic fungi.