ARS | Publication request: Fumonisin Production and Bioavailability to Maize Seedlings Grown from Seeds Inoculated with Fusarium Verticillioides and Grown in Natural Soils

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 6, 2006
Publication Date: August 1, 2006
Citation: Williams, L.D., Glenn, A.E., Bacon, C.W., Smith, M.A., Riley, R.T. 2006. Fumonisin production and bioavailability to maize seedlings grown from seeds inoculated with fusarium verticillioides and grown in natural soils. Journal of Agricultural and Food Chemistry 54(15):5694-5700.

Interpretive Summary: Fusarium verticillioides is a mold that infects maize and produces a family of toxic chemicals called fumonisins. The purpose of this study was to determine the ability of F. verticillioides to produce fumonisins in synthetic and natural soils and to determine if the toxic fumonisins could enter the cells of the roots and alter processes inside the roots. Maize seeds were exposed to a disease causing strain of F. verticillioides called MRC826 and the seeds were planted in synthetic and three different natural soils. There were statistically significant reductions in stalk weight and root mass and increased leaf lesions in the MRC826 treated seedlings in all soil types. Fumonisins were detected in all the soils of seedlings grown from MRC826 inoculated seeds. The fumonisin produced in the soils entered the cells and was thus biologically available to seedlings based on statistically significant elevation of chemicals inside the cells that are known to be elevated when the fumonisins block a step in the biosynthesis of a group of fats known as sphingolipids. The results indicate that F. verticillioides produced fumonisins in the autoclaved synthetic and natural soils and that the fumonisin produced is biologically available based on evidence of blockage of sphingolipid biosynthesis.

Technical Abstract: The fungus Fusarium verticillioides infects maize and produces fumonisins. The purpose of this study was to determine the ability of F. verticillioides to produce fumonisins in synthetic and natural soils and their biological availability to maize roots. Maize seeds were inoculated with a pathogenic strain of F. verticillioides (MRC826) and planted in synthetic and three different natural soils. There were statistically significant reductions in stalk weight and root mass and increased leaf lesions in the MRC826 treated seedlings in all soil types. Fumonisins were detected in all the soils of seedlings grown from MRC826 inoculated seeds. The fumonisin produced in the soils was biologically available to seedlings based on statistically significant elevation of free sphingoid bases and sphingoid base 1-phosphates in their roots. These results indicate that F. verticillioides produced fumonisins in the autoclaved synthetic and natural soils and that the fumonisin produced is biologically available based on evidence of inhibition of ceramide synthase.