FIG 4.

ΔMomca1, ΔMomca2, and ΔMomca1mca2 mutant strains showed resistance to the oxidative stress conditions compared to the WT strain. (A) Quantitative RT-PCR analysis showing the expression of M. oryzae metacaspase-encoding genes, MoMca1 and MoMca2, in the WT KV1 strain under oxidative stress conditions. Fungal mycelia were grown in liquid CM for 48 h at 25°C with agitation (150 rpm) before treatment with either 5 mM H₂O₂ or 100 μM menadione for 1 h. Expression was normalized to the housekeeping gene ACT1. Data are 2^−ΔΔCq ± standard deviations; N = 3 experiments. NT,  no treatment. (B to D) WT KV1 and ΔMomca strains were inoculated as 10-mm mycelial plugs onto 55-mm-diameter plates of complete medium containing H₂O₂ or menadione at the concentrations indicated. Images were taken at 7 days after growth. (C and D) Measurements of radial growth of M. oryzae WT and mutant strain mycelia under oxidative stress conditions. Results are means from three independent measurements. Error bars denote standard deviations. ns, not significant. Asterisks indicate statistically significant differences (**, P < 0.01; ***, P < 0.001; ****, P < 0.0001; one-way ANOVA with Tukey’s multiple-comparison test using GraphPad Prism 8).