Papers by Werner Mayerhofer
New Phytologist, Aug 6, 2021
Ectomycorrhizal plants trade plant-assimilated carbon for soil nutrients with their fungal partne... more Ectomycorrhizal plants trade plant-assimilated carbon for soil nutrients with their fungal partners. The underlying mechanisms are, however, not fully understood. Here we investigated the exchange of carbon for nitrogen in the ectomycorrhizal symbiosis of Fagus Sylvatica across different spatial scales from the root-system to the cellular scale. We provided 15 N-labelled Nitrogen to mycorrhizal hyphae associated with one half of the root system of young beech trees, while exposing plants to a 13 CO2 atmosphere. We analysed the short-term distribution of 13 C and 15 N in the root system with isotope-ratio mass spectrometry, and at the cellular scale within a mycorrhizal root tip with nanoscale-secondary-ion mass spectrometry (NanoSIMS). At the root-system scale, plants did not allocate more 13 C to root parts that received more 15 N. NanoSIMS imaging, however, revealed a highly heterogenous, and spatially significantly correlated distribution of 13 C and 15 N at the cellular scale. Our results indicate that, on a coarse scale, plants are not allocating a larger proportion of photoassimilated C towards root parts associated with N-delivering ectomycorrhizal fungi. Within the ectomycorrhizal tissue, however, recently plant-assimilated C and fungal-delivered N were spatially strongly coupled. NanoSIMS visualisation provide first insights into regulation of ectomycorrhizal C and N exchange at the microscale.
This dataset contains data that support the manuscript Mayerhofer et al (2021) "Recently pho... more This dataset contains data that support the manuscript Mayerhofer et al (2021) "Recently photoassimilated Carbon and fungal-delivered Nitrogen are spatially correlated at the cellular scale in the ectomycorrhizal tissue of<em> Fagus sylvatica", </em>The New Phytologist, DOI:10.1111/nph.17591 It contains the following data: (1) NanoSIMS imaging data, which was used for Fig. 4-7, is provided in NanoSIMS_control_root_tip.zip and NanoSIMS_labelled_root_tip.zip. Each zip-files contains: the original NanoSIMS images (.im) their related checkfiles (.chk_im) ROIs description (.rois.zip) of the unlabelled control and the labelled root tip section, respectively. ".im" and ".chk_im" are the original image data aquisition files from the NanoSIMS instrument. "rois.zip" files describe selected regions of interests and were created utilizing the OpenMIMS plugin (Center for Nano Imaging, https://nano.bwh.harvard.edu/MIMSsoftware) for the image ana...
Mycorrhizal fungi can connect multiple plants belowground forming Common Mycorrhizal Networks (CM... more Mycorrhizal fungi can connect multiple plants belowground forming Common Mycorrhizal Networks (CMNs). It has been suggested that CMNs facilitate mutualistic interactions between plants by providing channels to exchange carbon and nutrients. However, the terms of trade and mechanisms in which plants and their fungal partners interact are still not fully understood. Here, we investigated carbon and nitrogen transfer within a common ectomycorrhizal network between pairs of European beech trees. Our aim was to elucidate if there is C transfer between the root systems of plants connected via a CMN, and if CMNs amplify or alleviate belowground competition for nutrients.
Mycorrhizal fungi are an important partner of almost all land plants, who trade soil nutrients, s... more Mycorrhizal fungi are an important partner of almost all land plants, who trade soil nutrients, such as Phosphorus or Nitrogen, for photosynthetic Carbon (C). Moreover, mycorrhizal fungi connect multiple plants with their mycelium in so called Common Mycorrhizal Networks (CMNs). CMNs formed by ectomycorrhizal (EM) fungi are an inherent part of boreal and temperate forests, often termed the 'wood-wide web'. However, the role of these networks for plant belowground C allocation and distribution is not well known.
Frontiers in Microbiology, 2019
soil bacteria. Together, our results demonstrate that (i) ectomycorrhizal hyphae rapidly transfer... more soil bacteria. Together, our results demonstrate that (i) ectomycorrhizal hyphae rapidly transfer plant-derived C to bacterial communities in root-distant areas, and (ii) this transfer promptly responds to changing soil nutrient conditions.
Biogeochemistry, 2017
Rising carbon dioxide (CO 2) concentrations and temperatures are expected to stimulate plant prod... more Rising carbon dioxide (CO 2) concentrations and temperatures are expected to stimulate plant productivity and ecosystem C sequestration, but these effects require a concurrent increase in N availability for plants. Plants might indirectly promote N availability as they release organic C into the soil (e.g., by root exudation) that can increase microbial soil organic matter (SOM) decomposition (''priming effect''), and possibly the enzymatic breakdown of N-rich polymers, such as proteins, into bio-available units (''N mining''). We tested the adjustment of protein depolymerization to changing soil C and N availability in a laboratory experiment. We added easily available C or N sources to six boreal forest soils, and determined soil organic C mineralization, gross protein depolymerization and gross ammonification rates (using 15 N pool dilution assays), and potential extracellular enzyme activities after 1 week of incubation. Added C sources were 13 C-labelled to distinguish substrate from soil derived C mineralization. Observed effects reflect short-term adaptations of non-symbiotic soil microorganisms to increased C or N availability. Although C input promoted microbial growth and N demand, we did not find indicators of increased N mobilization from SOM polymers, given that none of the soils showed a significant increase in protein depolymerization, and only one soil showed a significant increase in N-targeting enzymes. Instead, our findings suggest that microorganisms immobilized
New Phytologist, 2021
Ectomycorrhizal plants trade plant-assimilated carbon for soil nutrients with their fungal partne... more Ectomycorrhizal plants trade plant-assimilated carbon for soil nutrients with their fungal partners. The underlying mechanisms are, however, not fully understood. Here we investigated the exchange of carbon for nitrogen in the ectomycorrhizal symbiosis of Fagus Sylvatica across different spatial scales from the root-system to the cellular scale. We provided 15 N-labelled Nitrogen to mycorrhizal hyphae associated with one half of the root system of young beech trees, while exposing plants to a 13 CO2 atmosphere. We analysed the short-term distribution of 13 C and 15 N in the root system with isotope-ratio mass spectrometry, and at the cellular scale within a mycorrhizal root tip with nanoscale-secondary-ion mass spectrometry (NanoSIMS). At the root-system scale, plants did not allocate more 13 C to root parts that received more 15 N. NanoSIMS imaging, however, revealed a highly heterogenous, and spatially significantly correlated distribution of 13 C and 15 N at the cellular scale. Our results indicate that, on a coarse scale, plants are not allocating a larger proportion of photoassimilated C towards root parts associated with N-delivering ectomycorrhizal fungi. Within the ectomycorrhizal tissue, however, recently plant-assimilated C and fungal-delivered N were spatially strongly coupled. NanoSIMS visualisation provide first insights into regulation of ectomycorrhizal C and N exchange at the microscale.
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Papers by Werner Mayerhofer