Defensin AFP1 inhibits appressorium formation and penetration of rice cells by the rice blast fungus Magnaporthe oryzae

The plant defensin antifungal peptide 1 (AFP1) is composed of only 51 amino acids and has potent antifungal activity against the rice blast fungus Magnaporthe oryzae. To elucidate the antifungal mechanisms of AFP1, we assessed the suppression of appressorium formation and hyphal penetration by M. oryzae. AFP1 interfered with appressorium formation and host cell penetration following to invasion in a dose-dependent manner. This is the first report of the prevention of M. oryzae infection in rice by AFP1 and our observations could help to develop resistant cultivars and antifungal formulations for use in agriculture.