Figure 1.
De novo sphingolipid synthesis in plants. This scheme has been adapted from a recent report (3) in which enzyme activities and sphingolipid composition in plants were summarized. The conversion of sphinganine to ceramide is inhibited by FB1 and AAL toxins. Variations in plant ceramides exist by the presence of hydroxylated or (poly)unsaturated sphinganine as the sphingoid base moiety or by 2-hydroxylated fatty acyl groups. Predominant complex sphingolipids are glycosylceramides and inositolphosphorylceramides. No plant genes involved in this process have been characterized yet.