Conidia from ΔatfA mutant lack CatA catalase activity; sakA and atfA genes are required for catA mRNA accumulation in response to nutrient starvation.
A. Thirty micrograms of protein extracts prepared from conidiospores of strains CLK43 (WT), TOL1 (ΔsakA), TFLΔatfA-02 (ΔatfA) were separated on native polyacrylamide gels to determine catalase activity as described previously (Navarro et al., 1996).
B. Mycelia from the same strains was grown for 12 h and shifted to the indicated nutrient stress condition for 3 h. As reported before, changes in catA mRNA size are observed under determined stress conditions (Navarro and Aguirre, 1998). Samples were collected to extract total RNA and used for Northern hybridization using a catA-specific probe. Bottom panel shows ribosomal RNA as loading controls.