A Mineral-Doped Micromodel Platform Demonstrates Fungal Bridging of Carbon Hot Spots and Hyphal Transport of Mineral-Derived Nutrients
Arunima Bhattacharjee, Odeta Qafoku, Jocelyn A. Richardson, Lindsey Anderson, Kaitlyn Schwarz, Lisa Bramer, Gerard X. Lomas, Daniel J. Orton, Zihua Zhu, Mark Engelhard, Mark Bowden, William Nelson, Ari Jumpponen, Janet Jansson, Kirsten Hofmockel, Christopher Anderton
Abstract
Fungal species are foundational members of soil microbiomes, where their contributions in accessing and transporting vital nutrients is key for community resilience. To date, the molecular mechanisms underlying fungal mineral weathering and nutrient translocation in low-nutrient environments remain poorly resolved due to the lack of a platform for spatial analysis of biotic weathering processes. Here, we addressed this knowledge gap by developing a mineral-doped soil micromodel platform. We demonstrate the function of this platform by directly probing fungal growth using spatially resolved optical and chemical imaging methodologies. We found the presence of minerals was required for fungal thigmotropism around obstacles and through soil-like pore spaces, and this was related to fungal transport of potassium (K) and corresponding K speciation from K-rich minerals. These findings provide new evidence and visualization into hyphal transport of mineral-derived nutrients under nutrient and water stresses.