11 Plant sphingolipids

Abstract

Plants contain a multiplicity of sphingolipid metabolites, such as long-chain bases, long-chain base phosphates, ceramides, glycosylceramides, phosphosphingolipids, and glycosyl inositol phosphorylceramide anchors of membrane proteins. Most of these compounds are also known from other eukaryotic organisms, but plant sphingolipids show some structural features that differ from those present in mammals and fungi. The functions of sphingolipids in plants have been poorly investigated and at present, the summarized data appear like a listing of unrelated phenomena. The elucidation of causal relationships between sphingolipid structures and functions has just started, indicating that some plant sphinglipids play roles similar to those known from mammals and fungi, whereas other functions may be due to plant-specific structures. The availability of the complete Arabidopsis thaliana genome together with the growing collection of sequence-indexed mutants will speed up the research on plant sphingolipids. An outline of the pathways of sphingolipid metabolism in plants is given based on biochemical data, the collection of functionally expressed enzymes as well as the sequence-based annotation of yet uncharacterized genes of A. thaliana which are probably involved in these reactions.