cAMP (Cyclic Adenosine 3 ,5 -monophosphate) signaling regulates appressorium formation in the Rice Blast fungus M. grisea (Magnaporthe grisea). Both saprophytic and pathogenic growth of M. grisea is regulated by AC (Adenylate Cyclase)/Mac1 but different effectors of cAMP mediate downstream effects specific for either cell morphogenesis or pathogenesis. M. grisea causes a devasting fungal disease of rice plants known as Rice Blast through appressorium (or infection tube) formation. cAMP mediates its effect on appressorium formation through PKA (Protein Kinase-A). A well-characterized intracellular target of cAMP in eukaryotic cells is the Regulatory subunit of PKA (Ref.1). The cAMP signaling which is required for growth and pathogenesis in M. grisea diverges at the level of PKA regulation. How external inductive signals are perceived by [...]