Suppression of Verticillium Wilt of Tomato by Difluoromethylornithine, a Suicidal Inhibitor of Polyamine Biosynthesis. Harry Mussell, Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853. Joe Osmeloski, Scott H. Wettlaufer, and Leonard Weinstein. Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853. Plant Dis. 71:313-316. Accepted for publication 1 August 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0313.

Difluoromethylornithine (DFMO), a specific inhibitor of polyamine biosynthesis via ornithine decarboxylase, retarded mycelial growth of Verticillium dahliae in vitro at concentrations as low as 5 µM. This inhibition could be reversed by putrescine, indicating that the mechanism of inhibition was prevention of polyamine biosynthesis in the mycelium. Postinoculation foliar application of DFMO delayed the appearance of symptoms of Verticillium wilt, and increasing doses of the inhibitor reduced the severity of the disease. These results indicate that it may be possible to control Verticillium wilts with target-specific inhibitors such as DFMO.