Synchronous spatiotemporal control of autophagy and organelle trafficking is necessary for infection by Magnaporthe oryzae

The blast fungus Magnaporthe oryzae infects plants using an appressorium that generates force to breach the leaf cuticle. Appressorium development follows a cell-cycle-regulated morphogenetic program requiring autophagy-associated death of the spore. How proliferative growth is coordinated with cell death remains unclear. Here, we show that each conidial cell follows a distinct developmental program essential for infection. Using quantitative live-cell imaging, we tracked 10 organelle types during appressorium morphogenesis in wild-type and Δatg8 mutant strains. Photoactivatable GFP microscopy revealed that mitochondria traffic from a single conidial cell into the appressorium, while the remaining cells undergo autophagy. Organelle inheritance occurs independently of cell-cycle checkpoints but coincides with spore germination. Photoconvertible fluorescence microscopy defined the temporal sequence of organelle movement and de novo biogenesis. Our findings reveal that coordinated spatiotemporal control of autophagy and organelle trafficking is necessary for rice blast infection.