alpha-Amylase Inhibitors from Wheat Against Development and Toxigenic Potential of Fusarium verticillioides

摘要

Fusarium verticillioides is one of the most important pathogens in maize and is a producer of fumonisin B-1 (FB1). Although reports of its presence in wheat are scarce, the susceptibility of this cereal to fungus of the same genus motivates interest in investigating compounds present in the grain with inhibitory activity against this species. The aim of this study was to extract alpha- amylase inhibitors from wheat and apply them in vitro to evaluate its effect on the development and expression of toxigenic potential of F. verticillioides. The a- amylase inhibitors, both crude (P-0) and purified (P-1), were applied to in vitro culture containing a pathogen mycelium disc. Mycelial growth of the pathogen, glucosamine content, a- amylase activity, and production of FB1 were investigated. All protein extracts of wheat showed the ability to inhibit pathogen growth, especially the extract P0 from cultivar Quartzo, which resulted in a reduction of glucosamine content (66%) and a- amylase activity (84%). Furthermore, the protein inhibitors showed antifumonisin effect, reducing by 33 and 47% the mycotoxin production when applied as P-0 and P-1,P- respectively. These results suggest that a- amylase inhibitor contributed to resistance against pathogen attack, acting in a diversified manner for each fungal species.