Summary Conidiation and appressorium differentiation are key processes for polycyclic dissemination and infection in many pathogens. Our previous study using DNA microarray led to the discovery of the MoYAK 1 gene in M agnaporthe oryzae that is orthologous to YAK 1 in S accharomyces cerevisiae . Although the mechanistic roles of YAK 1 in S . cerevisiae have been described, roles of MoYAK 1 in M . oryzae , a phytopathogenic fun...