Diversity and distribution of lichen-associated fungi in the Ny-Ålesund Region (Svalbard, High Arctic) as revealed by 454 pyrosequencing

Abstract

This study assessed the diversity and distribution of fungal communities associated with seven lichen species in the Ny-Ålesund Region (Svalbard, High Arctic) using Roche 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Lichen-associated fungal communities showed high diversity, with a total of 42,259 reads belonging to 370 operational taxonomic units (OTUs) being found. Of these OTUs, 294 belonged to Ascomycota, 54 to Basidiomycota, 2 to Zygomycota, and 20 to unknown fungi. Leotiomycetes, Dothideomycetes, and Eurotiomycetes were the major classes, whereas the dominant orders were Helotiales, Capnodiales, and Chaetothyriales. Interestingly, most fungal OTUs were closely related to fungi from various habitats (e.g., soil, rock, plant tissues) in the Arctic, Antarctic and alpine regions, which suggests that living in association with lichen thalli may be a transient stage of life cycle for these fungi and that long-distance dispersal may be important to the fungi in the Arctic. In addition, host-related factors shaped the lichen-associated fungal communities in this region. Taken together, these results suggest that lichens thalli act as reservoirs of diverse fungi from various niches, which may improve our understanding of fungal evolution and ecology in the Arctic.

ITS2 metabarcoding analysis complements lichen mycobiome diversity data

“…Lichen thalli, however, consist mainly of one fungus; when fungal barcodes are analyzed, a high fraction of the reads belong to the lichen mycobiont (Bates et al 2012; Zhang et al 2015; Fernández-Mendoza et al 2017), affecting the sampling depth of the other fungi. This shallow and uneven sampling depth of lichen-associated fungi causes a substantial loss of information, and biases the interpretation of species diversity patterns.…”

Molecular and morphological diversity of Trebouxia microalgae in sphaerothallioid Circinaria spp. lichens1

“…It is possible that different algal communities will adapt to different types of lichen thalli in different environments, or under specific environmental conditions (Zhang et al. ).…”

Endolichenic fungi: the lesser known fungal associates of lichens

“…It is suggested that such an association could have led to the evolution of plant endophytes (Arnold et al 2009). However, it appears that endolichenic fungi are distinct from the current endophytic fungi harboured by plants (U’Ren et al 2012; Zhang et al 2015). A comparison of endolichenic fungi at the genus level of some lichens and the endophytes of the trees on which these lichens were growing showed little overlap between them (Suryanarayanan et al 2005).…”