Abstract
The root-associated habit has evolved on numerous occasions in different fungal lineages, suggesting a strong evolutionary pressure for saprotrophic fungi to switch to symbiotic associations with plants. Species within the ubiquitous, saprotrophic genus Mycena are frequently major components in molecular studies of root-associated fungal communities, suggesting that an evaluation of their trophic status is warranted. Here, we report on interactions between a range of Mycena species and the plant Betula pendula. Seventeen Mycena species were inoculated onto B. pendula seedlings. Physical interactions between hyphae and fine roots were examined using differential staining and fluorescence microscopy. Physiological interactions were investigated using 14 C and 32 P to show potential transfer between symbionts. All Mycena species associated closely with fine roots, showing hyphal penetration into the roots, which in some cases were intracellular. Seven species formed mantle-like structures around root tips, but none formed a Hartig net. Mycena pura and M. galopus both enhanced seedling growth, with M. pura showing significant transfer of 32 P to the seedlings. Our results support the view that several Mycena species can associate closely with plant roots and some may potentially occupy a transitional state between saprotrophy and biotrophy.
Original language | English |
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Pages (from-to) | 601-612 |
Number of pages | 12 |
Journal | New Phytologist |
Volume | 227 |
Issue number | 2 |
Early online date | 13 Apr 2020 |
DOIs | |
Publication status | Published - Jul 2020 |
Bibliographical note
Acknowledgements:The European commission is acknowledged for a MSCA grant to C.B.H (grant no. 658849), the University of Oslo for further funding of the project, and the Swedish University of Agricultural Sciences for hosting parts of the experiments. C.B.H was funded by an internationalisation grant from the Carlsberg Research Grant Foundation at the time of writing (grant no. CF18-0809). We would like to thank Jerome Guerrand for aid in in vitro laboratory techniques, the Norwegian Forest Seed Center for provision of seeds, Hedda Weitz and Tatiana A. Semenova-Nelson and Taina Pennanen for provision of fungal cultures. We would like to thank Marc-André Selosse, Peter Kennedy and four anonymous referees for valuable comments to an earlier version of this manuscript.
Keywords
- biotrophy-saprotrophy continuum
- ecological niches
- functional diversity
- mycena
- root-associations
- biotrophy–saprotrophy continuum
- Mycena
- HOST-SPECIFICITY
- TREE ROOTS
- DECOMPOSITION
- MYCELIUM
- MYCORRHIZAL FUNGI
- ECTOMYCORRHIZAL FUNGI
- PHYLOGENETIC-RELATIONSHIPS
- LITTER
- FUNGAL COMMUNITIES
- SAPROTROPHIC FUNGI