Metabolomics imaging of arbuscular mycorrhizal fungi to inform a tri-partite metabolic model
EMSL Project ID
60998
Abstract
Developing environmentally sustainable sources of energy is a grand challenge of the 21st century. Plant feedstocks are promising renewable sources for sustainable aviation and transportation fuels, and the plant microbiome has a major impact on plant health and productivity. In particular, mutualistic associations between plants and arbuscular mycorrhizal fungi (AMF) can enhance plant feedstock productivity, resilience to stress, and carbon (C) allocation belowground. AMF are obligate biotrophs that form associations with most plant species globally. The “hyphosphere" surrounding AMF hyphae is key zone of interaction between mycorrhizal fungi and the soil microbial community, where nutrients are acquired that can be exchanged with the plant host. However, we know vanishingly little about the metabolomic conversation that occurs in situ in the hyphosphere between fungi and their surrounding microbiome.
We propose to combine a unique suite of bioimaging and mass spectrometry imaging techniques to answer fundamental questions about AMF physiology and nutrient foraging strategies; we will then use the acquired data to parameterize our AMF model (“Toadstool”) and test model predictions. We propose to analyze internal and external AMF metabolites using EMSL mass spectrometry imaging (MALDI, nanoDESI) using mycorrhizal split-plates and EMSL’s TerraForms “RhizoChip” synthetic soil habitats to determine context-specific AMF exudation. Our experiments will be conducted with axenic root tissue culture (split-plates) and with Brachypodium distachyon (rhizochips)—a model for candidate bioenergy grasses, such as switchgrass. First, we will evaluate how hyphal exudation changes with different hyphal structures and stages of mycorrhizal colony development. Next, to determine how the nutrient and community context impacts the AMF endo- and exometabolome, we will create patches of organic or inorganic nutrients in the presence and absence of a soil microbiome. We hypothesize that AMF will tailor its exudation to these two different nutrient habitats, and since AMF do not produce the enzymes required to decompose organic matter, we expect AMF will prioritize interactions with the soil microbiome in the presence of organic matter. Nutrients will be isotopically labeled to visualize nutrient exchange using mass spectrometry imaging at Inst-1 (NanoSIMS, TOF-SIMS). The acquired data will parameterize the Toadstool model, which is designed to simulate traits and tradeoffs of fungal partnerships using a hybrid modeling approach that combines a lattice-free network representation of AMF hyphal branching patterns and a community dynamic flux balance analysis.
Our proposed research and subsequent modeling efforts will support EMSL’s and DOE-BER’s missions to understand and predict biological processes that can be harnessed to enhance bioenergy production, sustainability, and C sequestration.
Project Details
Project type
Exploratory Research
Start Date
2024-01-01
End Date
N/A
Status
Active
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members