Candidate effector proteins from the maize tar spot pathogen Phyllachora maydis suppress immune responses

The fungal phytopathogen Phyllachora maydis is an obligate pathogen of maize and is the causal agent of tar spot disease. It was first identified in the United States in 2015 and has since spread to all corn producing regions within the U.S. Tar spot disease significantly reduces maize yields making it an economically important pathogen. To better understand the molecular mechanisms underlying the P. maydis – maize interaction, we investigated how P. maydis utilizes effectors to induce disease. Leveraging the most recent genome annotation, we identified eighteen candidate virulence (effector) proteins that are expressed during disease development and assessed whether these putative effectors suppress immune responses using heterologous expression systems, including Nicotiana benthamiana and the bacterial type III secretion system from Pseudomonas syringae DC3000.

This work was presented as a poster at the 2023 IS-MPMI meeting in Providence, RI