TurboID-Based Proximity Labeling for Exploiting Effector Interacting Proteins in the Fungal Maize Pathogen Ustilago maydis.

TurboID-based proximity labeling (PL) is an advanced method for identifying proteins in the immediate molecular environment of a protein of interest under physiological conditions. TurboID enables the rapid and covalent biotinylation of proteins in proximity to the bait proteins in living cells, capturing both stable and transient interactions with high temporal resolution. Most plant pathogens secrete effectors that modulate host immunity and facilitate infection. The effector-targeted host proteins are commonly involved in plant resistance or susceptibility. Elucidating these proteins is meaningful for crop improvement and design. The corn smut fungus Ustilago maydis causes tumor formation on all aerial parts of maize. The U. maydis-maize pathosystem is a model system for studying biotrophic fungi and their interactions with plants. To identify U. maydis effector targets in maize, a TurboID-based PL approach was developed to explore effector interactors in the U. maydis-maize pathosystem. This approach serves as a versatile tool for obtaining interactomes of effector baits in host tissues.