Ornithine and arginine decarboxylase activities and effect of some polyamine synthesis inhibitors on Gigaspora rosea germinating spores

SANNAZZARO A, C ALVAREZ, AB MENÉNDEZ, FL PIECKENSTAIN, E ALBERTÓ, OA RUIZ

Bariloche, Argentina

Congreso; XXXIX Reunión Anual de la Sociedad Argentina de Investigaciones Bioquímicas; 2003

Sociedad Argentina de Investigaciones Bioquímicas

The aim of the present study was to increase the knowledge on polyamine metabolism in AM fungi and to determine whether inhibitors of polyamine synthesis (which could be used as fungicides) may cause egative effects on spore germination and hyphal growth of Gigaspora rosea. In vivo decarboxylation of radioactive substrates showed that the ODC pathway is active and ADC activity occurs in G. rosea spores. ressults showed that urease is active during spore germination and provided evidence on the activity of NCPase, downstream of ADC. Effect of polyamine synthesis inhibitors on free polyamine content of spores, germination and germinating tube growth was studied. Spermine and spermidine were reduced byDFMA at concentrations of 0.05 and 0.5 mM, whereas CHA and DFMO, either alone or in combination, and putrescine, exerted no significant effects on spore germination at any of the assayed concentrations. In contrast, CHA reduced spore germination by more than 70%. On the basis of this results, the use of polyamine biosythesis inhibitors to control fungal pathogens would not affect germination and growth of G. rosea.