Differential sharing and distinct co‐occurrence networks among spatially close bacterial microbiota of bark, mosses and lichens‬‬

Abstract

Knowledge of bacterial community host-specificity has increased greatly in recent years. However, the intermicrobiome relationships of unrelated but spatially close organisms remain little understood. Trunks of trees covered by epiphytes represent complex habitats with a mosaic of ecological niches. In this context, we investigated the structure, diversity and interactions of microbiota associated with lichens, mosses and the bare tree bark. Comparative analysis revealed significant differences in the habitat-associated community structures. Corresponding co-occurrence analysis indicated that the lichen microbial network is less complex and less densely interconnected than the moss- and bark-associated networks. Several potential generalists and specialists were identified for the selected habitats. Generalists belonged mainly to Proteobacteria, with Sphingomonas as the most abundant genus. The generalists comprise microorganisms with generally beneficial features, such as nitrogen fixation or other supporting functions, according to a metagenomic analysis. We argue that beneficial strains shared among hosts contribute to ecological stability of the host biocoenoses.

Contrasting Patterns of the Bacterial Communities in Melting Ponds and Periglacial Rivers of the Zhuxi glacier in the Tibet Plateau

“…In our present study, co-occurrence networks in melt ponds and periglacial rivers suggested that most of the involved nodes belonged to the rare sub-communities. This pattern has previously been reported from other glacial environments in Tibet Plateau [23] and from other habitats, such as soil [58,59], rivers [60], and oceans [61]. Moreover, the over-proportional roles of rare taxa were also shown by our finding that all 7 keystones in melt ponds and 11 out of 12 keystones in periglacial rivers were affiliated with rare OTUs.…”

Mainland and island populations of Mussaenda kwangtungensis differ in their phyllosphere fungal community composition and network structure

“…5), thus indicating the potential for widespread cooperative and syntrophic relationships between most fungal members, or multiple trophic levels, as well as the potential for sharing niches based on nutritional preference and functional distinctiveness in the phyllosphere micro-environment. This overwhelmingly positive association has also been reported in microbial networks associated with mosses, lichens and the bark of maple trees 29 , and in the rhizosphere zone of wild oat 115 .…”

“…Further, exploration may uncover possible keystone taxa that exert a considerable impact on community structure and function, regardless of their abundance 20,21 . Co-occurrence network analysis based on high-throughput sequencing data has been increasingly applied to examine the ecological interactions among microorganisms in different habitats including water environments [22][23][24] , human and animal digestive tracts 25,26 , soil 27,28 , and tree trunks 29 . Nevertheless, compared to bacterial communities, far fewer studies have been conducted to investigate co-occurrence patterns of fungal microbiome especially in plant associated communities.…”

Deciphering functional diversification within the lichen microbiota by meta-omics

“…The available datasets were utilized for complementing analyses of the lichen microbiome [4, 28]. All datasets employed in this study were obtained with L. pulmonaria samples from the same sampling site.…”

“…Only recently, Aschenbrenner et al [3] reported about the presence of Spartobacteria ( Verrucomicrobia ) in lichens, a poorly investigated group earlier found to be abundant in soil and aquatic environments [9, 37, 71]. New data reinforced the hypothesis that specific members of Chthoniobacterales ( Spartobacteria ) and Sphingobacteriales ( Bacteroidetes ) could potentially be more important colonizers of L. pulmonaria [4]. A major obstacle in studying the as yet uncultivable Chthoniobacteria was their absence in former releases of public sequence databases due to their rather low occurrence in terrestrial habitats and thus low presence in most environmental samples.…”