Translocation of Sphingoid Bases and Their 1-Phosphates, but Not Fumonisins, from Roots to Aerial Tissues of Maize Seedlings Watered with Fumonisins

In an earlier study using maize seedlings grown from kernels inoculated with Fusarium verticillioides, fumonisin B-1 (FB1) was preferentially accumulated in leaf tissue compared to FB2 and FB3. The present study tested whether maize seedlings preferentially translocate FB1 when plants are watered with FB1 and/or FB2 without the fungus present. The results show that neither FB1 nor FB2 was translocated when administered in the watering solution, and although both FB1 and FB2 were taken up by the roots, the accumulation of FB2 in roots was significantly less than expected, indicating that FB1 was preferentially accumulated. In addition, there was clear evidence of ceramide synthase inhibition in the roots and sphingoid base and sphingoid base 1-phosphates accumulated in leaf tissue presumably due to translocation from the roots. These findings suggest that the fungus plant interaction is necessary for FB1 translocation in maize seedlings infected with F. verticillioides.