Bacterial community dynamics across developmental stages of fungal fruiting bodies

Abstract

Increasing evidence suggest that bacteria form diverse communities in various eukaryotic hosts, including fungi. However, little is known about their succession and the functional potential at different host development stages. Here we examined the effect of fruiting body parts and developmental stages on the structure and function of fungus-associated bacterial communities. Using high-throughput sequencing, we characterized bacterial communities and their associated potential functions in fruiting bodies from ten genera belonging to four major mushroom-forming orders and three different developmental stages of a model host species Cantharellus cibarius. Our results demonstrate that bacterial community structure differs between internal and external parts of the fruiting body but not between inner tissues. The structure of the bacterial communities also showed significant variation across fruiting body developmental stages. We provide evidence that certain functional groups, such as those related to nitrogen fixation, persist in fruiting bodies during the maturation, but are replaced by putative parasites/pathogens afterwards. These data suggest that bacterial communities inhabiting fungal fruiting bodies may play important roles in their growth and development.

Truffle Microbiome Is Driven by Fruit Body Compartmentalization Rather than Soils Conditioned by Different Host Trees

“…Interestingly, Planctomycetes was also abundantly found in soils but not in basidiomata belonging to the Agaricales genera: Amanita , Lactarius , Paxillus , and Russula in eastern Estonia ( 47 ). In addition, similar results have been reported in some Basidiomycetes , where the bacterial community structures differ between internal and external parts of the fruiting body but not between inner tissues ( 46 ). For fungi, our results demonstrated that (i) the Basidiomycota were dominant in soil, and the Rozellomycota tended to live in soil adhered to the truffle peridium, that is, a clear shift from Basidiomycota- to Rozellomycota-associated soils compared to truffle ascomata.…”

“…These specific conditions might be a deterministic factor of paramount ecophysiological relevance that strongly filter certain bacteria from the surrounding soils and allow them to proliferate in the truffle tissues due to the symbiotic or environmental requirements of ascomata-endophytic bacteria in ascomata ( 45 ). Physical and chemical changes include, for example, pH, temperature, oxygen levels, organic carbon availability, and ammonium released during chitin degradation in the course of fruit bodies maturation process, which may be selective factors for certain bacterial groups ( 46 , 47 ). At the same time, the soil surrounding the ascomata constitutes a reservoir of biodiversity, from which specific bacterial communities are differentially recruited both in the truffle compartments and in the ectomycorrhizosphere.…”

Bacterial community associated with the dry-rot fungusSerpula lacrymansis dominated by Firmicutes and Proteobacteria

“…We analyzed two mature and one not yet fully developed fruiting body with FISH, and importantly, the total number of signals on the three fruiting bodies was similar, although the immature fruiting body showed a higher content of β- and γ-Proteobacteria. This indicates a development-stage-dependent shift of the bacterial composition on fruiting bodies, similar to what has previously been shown for Cantharellus cibarius (48). Our investigation of mycelial and rhizomorphic tissues of S. lacrymans with different single probes revealed individual bacterial cells but no spatial bacterial dispersal pattern (Fig.…”

“…This indicates a development-stage-dependent shift of the bacterial composition on fruiting bodies, similar to what has previously been shown for Cantharellus cibarius(48). Our investigation of mycelial and rhizomorphic tissues of S. lacrymans with different single probes revealed individual bacterial cells but no spatial bacterial dispersal pattern (Fig.…”

Microbiota Associated with Different Developmental Stages of the Dry Rot Fungus Serpula lacrymans

“…The mature fruiting bodies (developing many basidiospores) were associated with β- and γ-Proteobacteria. This could hint at a development-dependent shift in the bacterial composition on fruiting bodies, similar to what has previously been shown for Cantharellus cibarius [ 71 ], but more targeted research is necessary to answer this question. Our investigation of the mycelial and rhizomorphic tissues of S. lacrymans with different single probes revealed individual bacterial cells but no spatial bacterial dispersal pattern ( Figure S8 ).…”