oa Natural and natural-like phenolic compounds inhibit trichothecene biosynthesis in the durum wheat pathogen Fusarium culmorum

Fusarium culmorum is a major fungal pathogen of wheat, causing foot and root rot (FRR) and fusarium head blight (FHB). Yield losses are reported as the grain becomes contaminated by mycotoxins. Among the most bioactive compounds are trichothecenes, sesquiterpene epoxides which are able to inhibit eukaryotic protein synthesis and may cause toxicoses on humans or animals consuming contaminated food or feed. Trichothecenes induce apoptosis and may play an important role in the aggressiveness of phytopathogenic Fusarium species towards plant hosts. The aim of this project is to design, prepare and study new natural and natural-like compounds to be applied in the control of F. culmorum mycotoxin production. Particular attention is paid to the selection and preparation of compounds with selective trichothecene B inhibitory activity compared to compounds showing both mycotoxin inhibitory and fungitoxic activities. The first inhibition experiments were performed using compounds belonging to the family of gallic acid, phenylpropanoids and cinnamic derived acids. In vivo and in vitro test and molecular modeling with computational studies were carried out. A straightforward thin layer chromatography (TLC) method and a quantitative LC-MS analysis were used to identify the presence of B trichothecenes and to evaluate the influence of each compound on different F. culmorum culture extracts. Preliminary results indicate that several molecules are able to inhibit the severity of F. culmorum in planta and its growth as well as trichothecene production in vitro. The level of inhibition of 3AcDON range from 67 to 100% under inducing conditions. Fast and effective methodologies for seed dressing were developed using a natural matrix.