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Morels ( Morchella spp.) are iconic edible mushrooms with a long history of human consumption. Some microbial taxa are hypothesized to be important in triggering the formation of morel primordia and development of fruiting bodies, thus, there is interest in the microbial ecology of these fungi. To identify and compare fungal and prokaryotic communities in soils where Morchella sextelata is cultivated in outdoor greenhouses, ITS and 16S rDNA high throughput amplicon sequencing and microbiome analyses were performed. Pedobacter , Pseudomonas , Stenotrophomonas , and Flavobacterium were found to comprise the core microbiome of M. sextelata ascocarps. These bacterial taxa were also abundant in the soil beneath growing fruiting bodies. A total of 29 bacterial taxa were found to be statistically associated to Morchella fruiting bodies. Bacterial community network analysis revealed high modularity with some 16S rDNA operational taxonomic unit clusters living in specialized fungal niches (e.g., pileus, stipe). Other fungi dominating the soil mycobiome beneath morels included Morchella , Phialophora , and Mortierella . This research informs understanding of microbial indicators and potential facilitators of Morchella ecology and fruiting body production.
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Associated bacterial communities, confrontation studies, and comparative genomics reveal important interactions between Morchella with Pseudomonas spp.
Members of the fungal genusMorchellaare widely known for their important ecological roles and significant economic value. In this study, we used amplicon and genome sequencing to characterize bacterial communities associated with sexual fruiting bodies from wild specimens, as well as vegetative mycelium and sclerotia obtained fromMorchellaisolates grownin vitro. These investigations included diverse representatives from both Elata and EsculentaMorchellaclades. Unique bacterial community compositions were observed across the various structures examined, both within and across individualMorchellaisolates or specimens. However, specific bacterial taxa were frequently detected in association with certain structures, providing support for an associated core bacterial community. Bacteria from the genusPseudomonasandRalstoniaconstituted the core bacterial associates ofMorchellamycelia and sclerotia, while other genera (e.g.,Pedobacterspp.,Deviosaspp., andBradyrhizobiumspp.) constituted the core bacterial community of fruiting bodies. Furthermore, the importance ofPseudomonasas a key member of the bacteriome was supported by the isolation of severalPseudomonasstrains from mycelia duringin vitrocultivation. Four of the six mycelial-derivedPseudomonasisolates shared 16S rDNA sequence identity with amplicon sequences recovered directly from the examined fungal structures. Distinct interaction phenotypes (antagonistic or neutral) were observed in confrontation assays between these bacteria and variousMorchellaisolates. Genome sequences obtained from thesePseudomonasisolates revealed intriguing differences in gene content and annotated functions, specifically with respect to toxin-antitoxin systems, cell adhesion, chitinases, and insecticidal toxins. These genetic differences correlated with the interaction phenotypes. This study provides evidence thatPseudomonasspp. are frequently associated withMorchellaand these associations may greatly impact fungal physiology.
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- Award ID(s):
- 1946445
- PAR ID:
- 10486752
- Publisher / Repository:
- Frontiers in Fungal Biology
- Date Published:
- Journal Name:
- Frontiers in Fungal Biology
- Volume:
- 4
- ISSN:
- 2673-6128
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/ffunb.2023.1285531
