INVESTIGADORES
PIECKENSTAIN Fernando Luis
artículos
Título:
Polyamine metabolism during the germination of Sclerotinia sclerotiorum ascospores and its relation with host infection
Autor/es:
GÁRRIZ A, MC DALMASSO, M MARINA, EI RIVAS, OA RUIZ & FL PIECKENSTAIN
Revista:
NEW PHYTOLOGIST
Editorial:
SpringerLink
Referencias:
Año: 2004 vol. 161 p. 847 - 854
ISSN:
0028-646X
Resumen:
Polyamine biosynthesis inhibitors were used to study polyamine metabolism during the germination of Sclerotinia sclerotiorum ascospores, and to evaluate the potential of polyamine biosynthesis inhibition for the control of ascospore-borne diseases in plants. The effects of inhibitors on ascospore germination, free polyamine levels, ornithine decarboxylase activity and development of disease symptoms on tobacco (Nicotiana tabacum) leaf discs inoculated with ascospores were determined. α-Difluoromethylornithine inhibited ornithine decarboxylase and decreased free spermidine levels, but had no effect on ascospore germination. Both, the spermidine synthase inhibitor cyclohexylamine and the S-adenosyl-methionine decarboxylase inhibitor methylglyoxalbis-[guanyl hydrazone] decreased free spermidine levels, but only the latter inhibited ascospore germination, at concentrations of 5 mM or higher. Lesion development on leaf discs was reduced by cyclohexylamine and methylglyoxalbis-[guanyl hydrazone], but not byá-difluoromethylornithine. In the absence of inhibitors, dormant ascospores contained higher polyamine levels than mycelium. Ascospore germination did not depend on ornithine decarboxylase activity and inhibitors of this enzyme will probably have a limited potential for the control of ascosporeborne plant diseases. On the contrary, spermidine synthase and S-adenosylmethionine decarboxylase could be more suitable targets for fungicidal action. The relative insensitivity of ascospore germination to polyamine biosynthesis inhibitors may be caused by their high polyamine content.