On the occurrence of peroxidase and laccase activity in lichens

Abstract

AbstractIn our earlier work, we demonstrated that the oxidases tyrosinase and laccase occur widely in lichens from the Peltigerales. Recently, we discovered the occurrence of another oxidoreductase, a heme peroxidase, in the Peltigeralean ‘jelly lichens’ Leptogium and Collema. Here we present the results of a survey of peroxidase activity in a range of lichens. In addition to the jelly lichens, strong peroxidase activity also occurs within the Peltigeralean genera Lobaria, Pseudocyphellaria and Sticta. Significant activity occurs in the cell wall, and, unlike laccase activity, peroxidase activity increases considerably following the rehydration of dry thalli. However, activity is absent from Peltigera and from the non-Peltigeralean species tested here. Electrophoretic investigation showed that lichen peroxidases are oligomeric. Possible roles for peroxidases in lichen biology are discussed.