Influence of Agmatine Supplemented Culture Medium on Metabolic Products and Gene Expression in Fusarium

In the previous experiments, we have to suggest that acetyl coenzyme A, which is a starting substrate for the biosynthesis of deoxynivalenol (DON), was simultaneously produced by activated b-oxidation. Furthermore, the content of 4-aminobutyrate (GABA) was increased in the agmatine addition culture medium. GABA can be synthesized from agmatine through putrescine and might influence the regulation of DON-related genes. When Fusarium asiaticum was cultivated in culture medium supplemented with agmatine, many amino acid and gene expression levels were increased. The nitrate reductase and nitrite reductase gene expression levels were increased, as were the expression levels of the glutamate synthase and glutamine synthase genes. Additionally, the major facilitator super family and the ABC transporters, glucose transporter, myo-inositol transport protein and maltose permease, were especially induced by the agmatine supplement. These results suggest that F. asiaticum sensed the defense response of the infected plants, in which anti-pathogenic substances, including polyamines, such as agmatine, are produced. Then, tocounter this response, F. asiaticum produced deoxynivalenol.