Low host specificity of root‐associated fungi at an Arctic site

Abstract

In High Arctic ecosystems, plant growth and reproduction are limited by low soil moisture and nutrient availability, low soil and air temperatures, and a short growing season. Mycorrhizal associations facilitate plant nutrient acquisition and water uptake and may therefore be particularly ecologically important in nutrition-poor and dry environments, such as parts of the Arctic. Similarly, endophytic root associates are thought to play a protective role, increasing plants' stress tolerance, and likely have an important ecosystem function. Despite the importance of these root-associated fungi, little is known about their host specificity in the Arctic. We investigated the host specificity of root-associated fungi in the common, widely distributed arctic plant species Bistorta vivipara, Salix polaris and Dryas octopetala in the High Arctic archipelago Svalbard. High-throughput sequencing of the internal transcribed spacer 1 (ITS1) amplified from whole root systems generated no evidence of host specificity and no spatial autocorrelation within two 3 m × 3 m sample plots. The lack of spatial structure at small spatial scales indicates that Common Mycelial Networks (CMNs) are rare in marginal arctic environments. Moreover, no significant differences in fungal OTU richness were observed across the three plant species, although their root system characteristics (size, biomass) differed considerably. Reasons for lack of host specificity could be that association with generalist fungi may allow arctic plants to more rapidly and easily colonize newly available habitats, and it may be favourable to establish symbiotic relationships with fungi possessing different physiological attributes.

Early detection of invasive species in marine ecosystems using high-throughput sequencing: technical challenges and possible solutions

“…Consequently, the report on errors caused by tag switching is rare in metabarcoding studies. Indeed, tag switching is common in multiple sequencing platforms such as Roche/454 (e.g., Blaalid et al 2014;Botnen et al 2014) and Illumina sequencing platforms (e.g., Esling et al 2015;Schnell et al 2015), and even in non-metabarcoding Illumina-based studies (e.g., Kircher et al 2011). Studies showed that up to 16 % and more than 2 % sequence reads had non-compatible tag combinations based on Roche/454 and Illumina sequencing platforms (van Orsouw et al 2007;Schnell et al 2015).…”

Endophytic Fungal Communities Associated with Vascular Plants in the High Arctic Zone Are Highly Diverse and Host-Plant Specific

“…Microbial communities in the Arctic represent the largest reservoir of incompletely described biodiversity adapted to extreme conditions. An important component of Arctic microbial diversity is represented by fungi, and fungi in the Arctic can be found in diverse habitats, such as soil [1–3], ice [4, 5], cryoconite holes [6], moss [7], dead leaves [8], washed-up and trapped wood [9], and plant roots [10–18]. In recent years, Arctic microbial communities have been seriously threatened by climate change, as Arctic ecosystems are experiencing the greatest rates of climate warming on the planet and marked changes have already been observed in terrestrial Arctic ecosystems [19].…”

“…Hitherto, the diverse fungal communities were found associated with roots of vascular plants in the Arctic [10–18] and the endophytic bacterial communities were also detected in Arctic vascular plants [28]. Only two studies reported on the endophytic fungi associated with above-ground plant tissues (i.e., leaves and stems) in the Arctic, including Dryas octopetala in Svalbard [24], Huperzia selago , Picea mariana , and Dryas integrifolia in the Canadian Arctic [29].…”

The genus Hebeloma in the alpine belt of the Carpathians including two new species

“…In addition to these traditional studies European Arctic-alpine fungal communities have been studied by high throughput sequencing (e.g. Bjorbaekmo et al 2010, Fujiyoshi et al 2011, Lentendu et al 2011, Geml et al 2012, Botnen et al 2014. Also the Arctic region of Greenland has been relatively well studied mycologically (Borgen et al 2006).…”