Inhibition of Pathogenicity of the Rice Blast Fungus by Saccharomyces cerevisiae α-Factor

Abstract

Magnaporthe grisea is a fungal pathogen with two mating types, MAT1-1 and MAT1-2, that forms a specialized cell necessary for pathogenesis, the appressorium. Saccharomyces cerevisiae alpha-factor pheromone blocked appressorium formation in a mating type-specific manner and protected plants from infection by MAT1-2 strains. Experiments with alpha-factor analogs suggest that the observed activity is due to a specific interaction of alpha-factor with an M. grisea receptor. Culture filtrates of a MAT1-1 strain contained an activity that inhibited appressorium formation of mating type MAT1-2 strains. These findings provide evidence that a pheromone response pathway exists in M. grisea that can be exploited for plant protection.

Signal Transduction Cascades Regulating Fungal Development and Virulence

“…Furthermore, culture filtrates of a MAT1-1 strain contained an activity that inhibited appressorium formation of mating type MAT1-2 strains. These findings suggest that activation of the pheromone response pathway may interfere with the signals leading to appressorium formation (24). Following this work, Shen et al reported the isolation of pheromone precursor genes in M. grisea.…”

Signaling via cAMP in fungi: interconnections with mitogen-activated protein kinase pathways

“…The mac1-associated phenotypes are rescued by the addition of cAMP. Exogenous cAMP was also able to suppress the inhibitory effect of Saccharomyces cerevisiae α-factor on appressorium formation by M. grisea (Beckerman et al 1997). Saccharomyces cerevisiae α-factor may inhibit appressorium formation by triggering a pheromone response pathway in M. grisea and by preventing cAMP accumulation (Beckerman et al 1997).…”

Peptide inhibitors of appressorium development in Glomerella cingulata

“…However, the peptide sequence is not known [8]. This study describes the e¡ect of K-mating factor on appressorium development in G. cingulata and the identity of a peptide, produced by G. cingulata, that inhibits appressorium development of G. cingulata conidia.…”

“…It has been shown that the S. cerevisiae K-mating factor can block the development of M. grisea appressorium [6,8] and that this fungus produces a peptide that inhibits appressorium development. However, the peptide sequence is not known [8].…”