FIG 3.

The A. alternata glutathione reductase 1 gene (AaGlr1) is required for fungal growth and pigmentation. (A) Δglr1 strains form less-dense colonies and produce fewer conidia and less melanin than the wild-type strain Z7 on PDA. (B) The addition of the oxidized (GSSG) or reduced (GSH) form of glutathione, or both (ox+re), to PDA restores radial growth (top view) and pigmentation (bottom view) of the Δglr1 and Δtrr1 strains, which have impaired thioredoxin reductase. All tests were repeated at least twice with three replicates of each treatment. Only representative replicates are shown.