Identifying global regulators of effector gene expression in the rice blast fungus

Magnaporthe oryzae is the causal agent of rice blast, one of the most serious diseases affecting rice cultivation around the world. The fungus also causes wheat blast, a disease that now threatens wheat production in South America and South Asia.

During plant infection, the rice blast fungus undergoes differential expression and secretion of a large set of effector proteins, many of which are directed into plant cells using a specific secretory pathway. M. oryzae possesses a large repertoire of effector proteins, with as many as 400 effector genes present in many isolates and this is a common feature of plant pathogenic fungi. How such a large family of effector-encoding genes is regulated is currently unknown.
This project will identify transcriptional regulators of effector gene expression in the rice blast fungus using a novel forward genetic screen that selects for mutations that affect the temporal expression patterns of known effector genes. This screen has already proven successful in identifying transcriptional regulators and offers considerable potential in identifying many of the key regulators of effector gene expression. The project will seek to define the transcriptional circuitry that governs plant infection by one of the world's most economically important plant pathogens.