PT  - JOURNAL ARTICLE
AU  - Magdalena Wutkowska
AU  - Dorothee Ehrich
AU  - Sunil Mundra
AU  - Anna Vader
AU  - Pernille B. Eidesen
TI  - Can root-associated fungi mediate the impact of abiotic conditions on the growth of a High Arctic herb?
AID  - 10.1101/2020.06.20.157099
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.06.20.157099
4099  - http://biorxiv.org/content/early/2020/06/20/2020.06.20.157099.short
4100  - http://biorxiv.org/content/early/2020/06/20/2020.06.20.157099.full
AB  - Arctic plants are affected by many stressors. Root-associated fungi are thought to influence plant performance in stressful environmental conditions. However, the relationships are not transparent; do the number of fungal partners, their ecological functions and community composition mediate the impact of environmental conditions and/or influence host plant performance? To address these questions, we used a common arctic plant as a model system: Bistorta vivipara. Whole plants (including root system) were collected from nine locations in Spitsbergen (n=214). Morphometric features were measured as a proxy for performance and combined with metabarcoding datasets of their root-associated fungi (amplicon sequence variants, ASVs), edaphic and meteorological variables. Seven biological hypotheses regarding fungal influence on plant measures were tested using structural equation modelling. The best-fitting model revealed that local temperature affected plants both directly (negatively aboveground and positively below-ground) and indirectly - mediated by fungal richness and the ratio of symbio- and saprotrophic ASVs. Fungal community composition did not impact plant measurements and plant reproductive investment did not depend on any fungal parameters. The lack of impact of fungal community composition on plant performance suggests that the functional importance of fungi is more important than their identity. The influence of temperature on host plants is therefore complex and should be examined further.Competing Interest StatementThe authors have declared no competing interest.