A double‐edged sword: reactive oxygen species (ROS) during the rice blast fungus and host interaction

Magnaporthe oryzae is a hemibiotrophic fungus that also needs host nutrients for propagation during infection. During its interaction with rice, reactive oxygen species (ROS) mediate important signaling reactions impacting both the pathogen and the host. In M. oryzae, the accumulation of ROS is important for the formation and maturation of the infectious structure appressorium. On the other hand, upon M. oryzae infection, rice generates further ROS to restrict invasive hyphae (IH) spreading. Despite ROS receptors remaining to be identified, M. oryzae recruits several strategies to respond and suppress ROS accumulation through the secretion of various effector molecules. These findings suggest that the balance between the generation and scavenging of ROS is sophisticatedly controlled during M. oryzae‐rice interaction. In this review, we discuss advances to understand the regulation mechanisms for the generation, accumulation, and transduction of ROS. Production of reactive oxygen species (ROS) is a ubiquitous defense response in plants. On the other hand, adapted pathogens evolved mechanisms to counteract the deleterious effects of host‐derived ROS and promote infection. Focusing on the rice blast fungus Magnaporthe oryzae and rice, we summarized recent advances in understanding some of the regulatory mechanisms for ROS generation, accumulation, and signaling transductionduring host–pathogen interaction.