Fig. 1

A. nidulans PrxA in tandem with G6PD is essential to fungal ROS defense. A Effects of disrupting prxA and catB on protection against H₂O₂. Fresh conidia (1 × 10⁵) of WT (WT_argB), ∆prxA, and ∆catB were inoculated on MM plates containing H₂O₂ at indicated concentrations and then incubated at 37 °C for 2 days. B Lack of PrxA resulted in intracellular accumulation of NADPH. After culture in liquid MM for 16 h, strains were treated with or without 1 mM H₂O₂ for 30 min before collection for determination of the NADPH/NADP⁺ ratio in cell lysates. NADPH/NADP⁺ is presented in relative quantitation; NADPH/NADP⁺ value of unstressed WT was set to 1 (mean ± SD; n = 3, *P < 0.05, **P < 0.01, one-way ANOVA). C–E Phenotypes of WT (WT_pyrG) and nP.gsdA strains on MM plates under H₂O₂ conditions using ammonium tartrate (left), proline (middle), or nitrate (right) as the sole nitrogen source. F NADPH/NADP⁺ ratios in WT (WT_pyrG) and nP.gsdA strains. Strains were cultivated in liquid MM with ammonium tartrate (left), proline (middle), or nitrate (right) as the sole nitrogen source for 16 h, and then the NADPH/NADP⁺ ratios in cell lysates were quantified and compared; NADPH/NADP⁺ value of WT cultivated with each nitrogen source was set to 1 (mean ± SD; n = 3, *P < 0.05, **P < 0.01, t-test)