Identifying genetic control of reactive oxygen species in Magnaporthe oryzae (the rice blast fungus) through development, screening and characterization of a random insert mutant library
Date
2022
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Publisher
University of Delaware
Abstract
Magnaporthe oryzae is an ascomycete pathogen that can cause devastating blast diseases on important grasses such as rice, barley, finger millet and more recently wheat. Our lab’s primary goal is to better understand the role of reactive oxygen species (ROS) in susceptible interactions between M. oryzae and two of its hosts, rice and barley. Reactive oxygen species contribute to plant basal defenses even during a susceptible interaction. Many labs including ours have identified fungal genes in major ROS scavenging pathways that mitigate the impact of plant-produced ROS on fungal penetration and colonization. Interestingly, when these genes are deleted from the fungus, the fungus is still able to cause disease even though reduced, indicating additional genes involved in ROS management during pathogenesis. Forward genetics is a powerful method of identifying unknown genes that underlie phenotypes and here, we describe development and characterization of a 2,000 random mutant library coupled with an endogenous ROS sensor to identify additional fungal genes involved in ROS fungal virulence. Previous work in our lab generated a M. oryzae strain containing an endogenous sensor of ROS, which we showed specifically detected hydrogen peroxide during infection of rice and barley. We hypothesized that forward genetics, coupled with this endogenous sensor, would identify additional fungal genes involved in ROS management. We present characterization of our mutant library, including pathogenicity assay and sequencing results from a subset of selected mutants.
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Keywords
HyPer-sensor, Magnaporthe oryzae, Mutant library, Reactive oxygen species, Rice blast disease