Activity of key A. flavipes enzymes involved in sulfur and sulfur amino acid metabolism in response to sulfur starvation.

Spores of A. flavipes were starved of sulfur (cultured on Dox’s medium with no S compounds) or non-starved control (cultured on Dox’s liquid medium with 5 mM MgSO4) for 24 h, then inoculated to Dox’s liquid medium amended with MgSO4, L-Methionine, L-Cysteine and L-Cystine.–S control represents culture on Dox’s medium with no sulfur compounds as described in the Methods and Materials section. Enzyme activity of ATP-Sulfurylase (A), sulfite reductase (B), cysteine synthase (C), Cystathionine β- lyase (D), cystathionine γ-lyase (E), L-methioninase (F), Glutathione reductase (G), and glutathione peroxidase (H) were determined as described in Materials and Methods. Data shown are means ± SD of three replications.