Sugar- and Nitrogen-Dependent Regulation of an <i>Amanita muscaria</i> Phenylalanine Ammonium Lyase Gene

Abstract

The cDNA of a key enzyme of secondary metabolism, phenylalanine ammonium lyase, was identified for an ectomycorrhizal fungus by differential screening of a mycorrhizal library. The gene was highly expressed in hyphae grown at low external monosaccharide concentrations, but its expression was 30-fold reduced at elevated concentrations. Gene repression was regulated by hexokinase.