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Inoculating and Observing Arbuscular Mycorrhizal Cultures on Superabsorbent Polymer-Based Autotrophic Systems
Published on: June 14, 2024
Sulfur transfer through an arbuscular mycorrhiza
James W Allen1, Yair Shachar-Hill
1Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA. allenj28@msu.edu
Plant Physiology
|November 4, 2008
Summary
Arbuscular mycorrhizal symbiosis enhances plant sulfur uptake. The fungus transfers sulfate and reduced sulfur compounds, with fungal gene expression regulating this crucial nutrient exchange for plant nutrition.
Area of Science:
- Plant Biology
- Mycology
- Biochemistry
Background:
- Sulfur (S) is essential for plant nutrition, yet its uptake via arbuscular mycorrhizal (AM) symbiosis is understudied.
- AM fungi form symbiotic relationships with plant roots, facilitating nutrient exchange.
Purpose of the Study:
- To investigate the role of AM symbiosis in sulfur uptake and transfer to host plants.
- To analyze the influence of different sulfur sources and concentrations on fungal S assimilation and root partitioning.
Main Methods:
- Utilized 35S-labeling experiments with transformed carrot roots and Glomus intraradices in bicompartmental petri dishes.
- Analyzed uptake, transfer, and partitioning of 35SO4(2-), [35S]Cys, and [35S]Met under varying conditions.
- Quantified fungal transcript levels for S assimilatory genes.
Main Results:
- AM fungi effectively take up and transfer sulfate to mycorrhizal roots, increasing root S content by 25% at moderate concentrations.
- High external sulfate levels and the addition of methionine, cysteine, or glutathione to the fungal compartment significantly altered sulfate transfer.
- Similar S transfer occurred regardless of whether sulfate, cysteine, or methionine was supplied to the fungus, and fungal trans-sulfuration pathway genes were identified.
Conclusions:
- Arbuscular mycorrhizal symbiosis plays a significant role in plant sulfur acquisition.
- Fungal uptake and transfer of sulfur are influenced by external sulfur availability and compounds supplied to the fungus.
- Transcriptional regulation of fungal sulfate transporters is implicated in controlling S transfer to the host plant, supporting a model of AM-mediated S acquisition.
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