Physisporinus is an important mycorrhizal partner for mycoheterotrophic plants: Identification of mycorrhizal fungi of three Yoania species

Mycoheterotrophic orchids depend completely on mycorrhizal fungi for their supply of carbon. The life-history traits of mycoheterotrophic plants (MHPs) can differ according to the characteristics of the associated mycorrhizal fungi. We compared the life-history strategies of two mycoheterotrophic orchids associated with wood- and leaf litter-decaying fungi over a maximum of six years of field monitoring. Seventy percent of the aboveground stems of Erythrorchis altissima, associated with wood-decaying fungi, disappeared from the host wood within two years after tagging, likely due to nutrient depletion. In contrast, Gastrodia confusa, associated with leaf litter-decaying fungi, occurred continuously (18 to 108 fruiting stalks) every year within a small-scale plot (12 × 45 m) for six years through seed and clonal propagation. Our results support the idea that mycoheterotrophic orchids associated with wood-decaying fungi disappear from their habitats due to nutrient depletion after their host wood has mostly decayed, while mycoheterotrophic orchids associated with leaf litter-decaying fungi can survive in small-scale habitats where substantial leaf fall regularly occurs to sustain the associated fungi. Our study provides basic information about a unique life-history strategy in MHPs associated with saprotrophic fungi and an understanding of the variation in life-history strategies among MHPs.

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Mycoheterotrophic plants living on arbuscular mycorrhizal fungi are generally enriched in 13 C, 15 N and 2 H isotopes

Journal of Ecology ◽

10.1111/1365-2745.13381 ◽

2020 ◽

Vol 108 (4) ◽

pp. 1250-1261 ◽

Cited By ~ 6

Author(s):

Sofia I. F. Gomes ◽

Vincent S. F. T. Merckx ◽

Judith Kehl ◽

Gerhard Gebauer

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Mycoheterotrophic Plants

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Plant cheaters preferentially target arbuscular mycorrhizal fungi that are highly connected to mutualistic plants

10.1101/867259 ◽

2019 ◽

Author(s):

Sofia IF Gomes ◽

Miguel A Fortuna ◽

Jordi Bascompte ◽

Vincent SFT Merckx

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

List Type ◽

Root Tips ◽

Motif Analysis ◽

Carbon Availability ◽

Random Interactions ◽

Mycorrhizal Networks ◽

Mycoheterotrophic Plants ◽

Fungal Association

AbstractTo address how arbuscular mycorrhizal networks sustain cheaters – mycoheterotrophic plants that obtain both carbon and soil nutrients from fungi – here we investigate how mutualistic and antagonistic mycorrhizal networks are interlinked.We sampled root tips of mutualistic and cheater plants in two tropical forest plots and assembled the combined network between fungi linked to mutualistic and cheater plants (i.e., tripartite network) using DNA sequencing. We compared the interactions of the fungi in the mutualistic and antagonistic networks and searched for motifs (simple subgraphs that are overrepresented in complex networks) representing simultaneous links of particular mutualist and cheater plants to pairs of fungi to investigate fungal association preferences.Within the tripartite network, cheater plants are highly connected and interact with the majority of available fungal partners (74%), and we find that fungi that share interactions with the same mutualistic plants also share interactions with sets of cheaters. The motif analysis demonstrates that cheaters preferentially interact with sets of fungi that are linked to particular plant species.Our findings indicate that cheaters preferentially interact with fungi that are well-connected to particular mutualistic plants. We hypothesize that these non-random interactions may result from trait-based selection and that this strategy maximizes carbon availability for cheaters.

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Evolutionary histories and mycorrhizal associations of mycoheterotrophic plants dependent on saprotrophic fungi

Journal of Plant Research ◽

10.1007/s10265-020-01244-6 ◽

2021 ◽

Author(s):

Yuki Ogura-Tsujita ◽

Tomohisa Yukawa ◽

Akihiko Kinoshita

Keyword(s):

Leaf Litter ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Mycorrhizal Symbiosis ◽

Free Living ◽

Saprotrophic Fungi ◽

Culture Systems ◽

Ecm Fungi ◽

Mycoheterotrophic Plants

AbstractMycoheterotrophic plants (MHPs) are leafless, achlorophyllous, and completely dependent on mycorrhizal fungi for their carbon supply. Mycorrhizal symbiosis is a mutualistic association with fungi that is undertaken by the majority of land plants, but mycoheterotrophy represents a breakdown of this mutualism in that plants parasitize fungi. Most MHPs are associated with fungi that are mycorrhizal with autotrophic plants, such as arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. Although these MHPs gain carbon via the common mycorrhizal network that links the surrounding autotrophic plants, some mycoheterotrophic lineages are associated with saprotrophic (SAP) fungi, which are free-living and decompose leaf litter and wood materials. Such MHPs are dependent on the forest carbon cycle, which involves the decomposition of wood debris and leaf litter, and have a unique biology and evolutionary history. MHPs associated with SAP fungi (SAP-MHPs) have to date been found only in the Orchidaceae and likely evolved independently at least nine times within that family. Phylogenetically divergent SAP Basidiomycota, mostly Agaricales but also Hymenochaetales, Polyporales, and others, are involved in mycoheterotrophy. The fungal specificity of SAP-MHPs varies from a highly specific association with a single fungal species to a broad range of interactions with multiple fungal orders. Establishment of symbiotic culture systems is indispensable for understanding the mechanisms underlying plant–fungus interactions and the conservation of MHPs. Symbiotic culture systems have been established for many SAP-MHP species as a pure culture of free-living SAP fungi is easier than that of biotrophic AM or ECM fungi. Culturable SAP-MHPs are useful research materials and will contribute to the advancement of plant science.

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Heavy metal binding by mycorrhizal fungi

Physiologia Plantarum ◽

10.1034/j.1399-3054.1994.920224.x ◽

1994 ◽

Vol 92 (2) ◽

pp. 364-368 ◽

Cited By ~ 5

Author(s):

Ulrich Galli ◽

Hannes Schuepp ◽

Christian Brunold

Keyword(s):

Heavy Metal ◽

Metal Binding ◽

Mycorrhizal Fungi ◽

Heavy Metal Binding

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Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

10.32942/osf.io/t82ug ◽

2019 ◽

Cited By ~ 1

Author(s):

Coline Deveautour ◽

Sally Power ◽

Kirk Barnett ◽

Raul Ochoa-Hueso ◽

Suzanne Donn ◽

...

Keyword(s):

Community Composition ◽

Plant Community ◽

Plant Communities ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Temporal Dynamics ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Plant Responses ◽

Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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