Shared mycorrhizae but distinct communities of other root-associated microbes on co-occurring native and invasive maples

Abstract

Background Biological invasions are major drivers of environmental change that can significantly alter ecosystem function and diversity. In plants, soil microbes play an important role in plant establishment and growth; however, relatively little is known about the role they might play in biological invasions. A first step to assess whether root microbes may be playing a role in the invasion process is to find out if invasive plants host different microbes than neighbouring native plant species. Methods In this study we investigated differences in root associated microbes of native sugar maple (Acer saccharum Marsh.) and exotic Norway maple (A. platanoides L.) collected from a forested reserve in eastern Canada. We used microscopy to examine root fungi and high-throughput sequencing to characterize the bacterial, fungal and arbuscular mycorrhizal communities of both maple species over one growing season. Results We found differences in root associated bacterial and fungal communities between host species. Norway maple had a higher bacterial and fungal OTU (operational taxonomic units) richness compared to sugar maple, and the indicator species analysis revealed that nine fungal OTUs and three bacterial OTUs had a significant preference for sugar maple. The dominant bacterial phyla found on the roots of both maple species were Actinobacteria and Proteobacteria. The most common fungal orders associated with the Norway maple roots (in descending order) were Helotiales, Agaricales, Pleosporales, Hypocreales, Trechisporales while the Agaricales, Pleosporales, Helotiales, Capnodiales and Hypocreales were the dominant orders present in the sugar maple roots. Dark septate fungi colonization levels were higher in the sugar maple, but no differences in arbuscular mycorrhizal fungal communities and colonization rates were detected between maple species. Discussion Our findings show that two congeneric plant species grown in close proximity can harbor distinct root microbial communities. These findings provide further support for the importance of plant species in structuring root associated microbe communities. The high colonization levels observed in Norway maple demonstrates its compatibility with arbuscular mycorrhizal fungi in the introduced range. Plant-associated microbial communities can affect host fitness and function in many ways; therefore, the observed differences suggest a possibility that biotic interactions can influence the dynamics between native and invasive species.

Regional variation drives differences in microbial communities associated with sugar maple across a latitudinal range

“…The mutualistic arbuscular mycorrhizae fungi had the most striking decrease in diversity and richness along the latitudinal gradient (Figure 2). AMF colonization rates can be quite high, up to 80% or higher in seedlings (De Bellis et al, 2019), which is likely to have contributed to nutrient capture at this early life history stage (van der Heijden et al, 2006). Boreal forests are dominated by coniferous trees that form associations with ectomycorrhizal fungi (Read, 1991;Steidinger et al, 2019); therefore, AMF inoculum sources may be lower in boreal forest soils.…”

Mycobiota of Fine Roots of Pseudotsuga menziesii Introduced to the Native Forest Environment

“…For plants that rely on symbiotrophic fungi in the soil (e.g., ectomycorrhizal fungi), several strategies have been proposed to facilitate invasion. Plants are not hindered in their new range if they are able to associate with novel mutualists, associate with commonly distributed symbionts, or invade together with their native symbionts [97,98]. The obtained results indicate that P. menziesii finds favorable conditions for the establishment of mutualistic contacts in the conditions of North-Eastern Poland, allows local populations of symbiotic fungi, and is attacked by pathogenic organisms to a small extent [99].…”

A single range‐expanding species reshapes alpine ecosystems and their belowground diversity

“…2 system, with Index (i5) on the forward primer and Index (i7) on the reverse primer. PCR amplification and Illumina MiSeq sequencing procedures refer to DeBellis et al (2019). A total of 321 samples, including negative controls were sequenced.…”