Tracing single-cell scale chemical signaling between interacting soil fungi

Introduction

Multiple species of fungi co-exist in soils and play an important role in biogeochemical cycles. To survive in a resource-limited environment, they have developed the means for interspecific communication and warfare via an arsenal of secreted secondary metabolites.

Research Gap

The specific ecological role of those metabolites and the extent to which they affect biogeochemical cycling during fungal interactions remains unknown. Because they are secreted and act at a single-cell scale, tracing them ‘then and there’ can aid in identifying potential triggers for their production and clarifying their function.

Current Limitations

Currently used methods have either insufficient resolution or are destructive, and are not suitable for such analyses.

Proposed Methodology

Here, I will use my expertise in spectroscopy techniques to:

1. Establish experimental protocols for the single-cell scale fungal secondary metabolite identification and characterization using surface-enhanced Raman scattering (SERS) microspectroscopy. This method employs the optical properties of gold nanoparticles for molecule-specific sensing and has been shown in biomedical research to have extraordinary potential for studying microbial metabolic processes.

2. Combine it with microfluidics-based soil chips that provide visual access to and mimic real ecosystems via control over the biotic and abiotic environment of soil microbes.

Objectives

Ultimately, my aim is to offer the community of soil fungal ecologists a game-changing new tool to study ecosystem functions of secondary metabolites in more realistic settings.

Experimental Applications

I will then use the approach to:

1. Determine how interspecific fungal interactions under varying nutrient conditions affect the composition of their secondary metabolome and its functions live and at a single-cell scale.

2. Conduct additional transcriptome analysis to reveal fungal genes involved in the up- or downregulation of metabolite biosynthesis, as well as extracellular enzyme production for organic matter degradation and nutrient acquisition.