Abstract
Sphingolipids are ubiquitous and essential components in the membrane of eukaryotic cells and also known as bioactive molecules. In plant sphingolipids, C4 positions of the LCBs are commonly hydroxylated by dihydrosphingosine C4 hydroxylase (DSH). There were five DSH genes (OsDSH1 to OsDSH5) in the rice genome. The expression patterns of OsDSH1 to OsDSH5 were analyzed by the GUS reporter assay as well as RT-PCR. All five genes showed different expression patterns with each other. When DSH enzyme-activities of these OsDSHs were determined by yeast complementation test, it was shown that OsDSH1 and OsDSH4 efficiently restored the yeast DSH mutation (Δsur2), suggesting they functioned as DSH. The transformants with RNAi to OsDSH1 showed severe reduction of their fertilities. On the other hand, the overexpressed-transformants of OsDSH5 showed the dwarf phenotype. These results suggested that functions of OsDSHs diverge in the tissues in with specific gene expression.
