P-175 - Unraveling the Molecular Mechanisms of Immune Suppression by Synchytrium endobioticum Pathotype 18

Synchytrium endobioticum, causal agent for potato wart disease, is a persistent quarantine pathogen known for its ability to survive in soil for decades. Among more than 40 pathotypes, types 1, 2, 6, and 18 are particularly problematic in Europe. Infection of susceptible hosts by the pathogen occurs without visible mycelium leading to a lack of understanding of the physiological and molecular basis of the interaction

This study investigates pathotype 18, focusing on its potential to suppress host immunity. With the previous transcriptomic analysis, we identified 50 candidate effector proteins characterized by specific sequence features such as signal peptides and disulfide bonds. To assess their in interfering with Pattern-Triggered Immunity (PTI), we utilized a two-step agroinfiltration assay in Nicotiana benthamiana. In the first step, leaves were infiltrated with Agrobacterium carrying the effector constructs. After 48 hours, a second infiltration with Agrobacterium expressing GFP was conducted. Of the 50 candidates, 36 showed increased GFP fluorescence, suggesting a function in PTI suppression.

These insights into the effectors of S. endobioticum enhance our understanding of host-pathogen interactions and provide a foundation for developing resistance strategies. Future work will focus on characterizing effector targets, contributing to the breeding of resistant potato varieties and more durable disease management practices.