Poliamines metabolism during sclerotial development of Sclerotinia sclerotiorum
GÁRRIZ, ANDRÉS; GONZALEZ, ELISA; MARINA, MARÍA; RUIZ, OSCAR A; PIECKENSTAIN, FERNANDO L
Año: 2008 vol. 112 p. 414 - 414
A study on polyamine metabolism and the consequences of polyamine biosynthesis inhibition on the development of Sclerotinia sclerotiorum sclerotia was conducted. Concentrations of the triamine spermidine and the tetramine spermine as well as ornithine decarboxylase and S-adenosyl-methionine decarboxylase activities decreased during sclerotia maturation. In turn, the concentration of the diamine putrescine was reduced at early stages of sclerotial development but it increased later on. This increment was not related to de novo biosynthesis, as demonstrated by the continuous decrease in ornithine decarboxylase activity. Alternatively, it could be explained by the release of putrescine from the conjugated polyamine pool. á-Difluoro-methylornithine and cyclohexylamine, which inhibit putrescine and spermidine biosynthesis respectively, showed to decrease mycelial growth. Nevertheless, they did not reduce the number of sclerotia produced in vitro even though they proved to perturb polyamine metabolism during sclerotial development. It can be concluded that sclerotial development is less dependent on polyamine biosynthesis than mycelial growth, and that the release of putrescine from the conjugated polyamine pool is a typical feature of sclerotial development. Further considerations on polyamine metabolism concerning sclerotial development and the potential of polyamine biosynthesis inhibition as a strategy for the control of plant diseases caused by sclerotial fungi are discussed.