ETHANOL PERTURBS POLYAMINE METABOLISM IN THE PHYTOPATHOGENIC FUNGUS PYRENOPHORA-AVENAE

Biomass production by the plant pathogenic fungus Pyrenophora avenae w as reduced following growth in 1, 3 and 6% ethanol. Although cadaverin e concentration was not affected by growth in ethanol, putrescine and spermine concentrations were increased following growth in 3% ethanol and concentrations of spermidine and spermine were substantially incre ased following exposure to 6% ethanol. These changes were accompanied by significant increases in the activities of the polyamine biosynthet ic enzymes ornithine decarboxylase and S-adenosylmethionine decarboxyl ase and in the flux of label from ornithine into the polyamines. Forma tion of the cadaverine derivatives aminopropylcadaverine and N,N-bis(3 -aminopropyl)cadaverine was greatly increased in P. avenue exposed to 6% ethanol, probably via the action of lysine decarboxylase, S-adenosy lmethionine decarboxylase and the aminopropyltransferases; There was a lso a doubling of polyamine oxidase activity following fungal growth i n 6% ethanol. (C) 1998 Federation of European Microbiological Societie s. Published by Elsevier Science B.V. All rights reserved.