Fumonisins: synthesis and role in the Fusarium verticillioides-maize interaction

Abstract

Fusarium verticillioides is the main fungal pathogen that affects the productivity of maize worldwide. The fungus penetrates the plant by different routes and infects roots, stem and cob. The pathogen produces several toxins in tissue and corn kernels, which affect their quality. Fumonisins are the major toxins produced by this fungus. The ability to produce them depends on the presence of several genes encoding the enzymes responsible for biosynthesis. The regulation of the synthesis is very complex and depends on environmental and nutritional factors, as well as multiple signaling pathways. This is reflected by the high variability in fumonisin production among F. verticillioides strains. Fumonisins are virulence factors because their production is associated with a greater capacity to infect maize seedlings. However, this role is not clear for ear infection and rotting. In maize, fumonisins have three molecular targets: sphinganine N-acyl-transferase, plasma membrane proton ATPase and the basic β-1,3-glucanases. These three enzymes have important physiological functions and also participate in the plant defense response against fungal pathogens.