[Effect of acetate on the formation of the phyoeffector tentoxin by Alternaria alternata (Fr.) Keissler].

The effect of the cosubstrate acetate on the formation of the phytotoxic substance tentoxin by Alternaria alternata (Fr.) Keissler was investigated. Acetate was taken up and metabolized during growth. The added acetate stimulated considerably the biosynthesis of tentoxin depending on its concentration and time of introduction. There was an increased incorporation of (U-14C)-glucose into the toxin molecule in the presence of acetate in the medium. The results indicate an induction of the biosynthesis of tentoxin by the precursor acetate, probably mediated through the accumulation of the glycolytic intermediates pyruvate and phosphoenolpyruvate.