Autophagic fungal cell death is necessary for infection by the rice blast fungus. Science 312: 580–583

Rice blast is caused by the fungus Magnaporthe grisea, which elaborates specialized infection cells called appressoria to penetrate the tough outer cuticle of the rice plant Oryza sativa. We found that the formation of an appressorium required, sequentially, the completion of mitosis, nuclear migration, and death of the conidium (fungal spore) from which the infection originated. Genetic intervention during mitosis prevented both appressorium development and conidium death. Impairment of autophagy, by the targeted mutation of the MgATG8 gene, arrested conidial cell death but rendered the fungus nonpathogenic. Thus, the initiation of rice blast requires autophagic cell death of the conidium. R ice blast disease is one of the most serious and recurrent problems affect-ing rice production worldwide (1–4). The disease is caused by Magnaporthe grisea (Hebert) Barr (anamorph Pyricularia grisea Sacc), an ascomycete fungus that produce