A germination-specific epoxide hydrolase from Euphorbia lagascae.

The endosperm of Euphorbia lagascae Spreng. seeds contains high levels of the epoxidated fatty acid vernolic acid [12(S),13(R)-epoxy-12-octadecenoic acid]. To learn more about the function and metabolism of vernolic acid, we have initiated an investigation into the gene activities involved in the processes of vernolic acid mobilization and oxidation during germination. Here we report the cloning and characterization of a soluble epoxide hydrolase from E. lagascae. Epoxide hydrolases are a group of functionally related enzymes that catalyze the co-factor-independent hydrolysis of epoxides to their corresponding vicinal diols by the addition of a water molecule. A detailed investigation of the transcription pattern of the E. lagascae epoxide hydrolase gene shows that it is induced during germination. Results from in situ hybridization show that the gene is expressed in the cotyledons and in the hypocotyl. We conclude that soluble epoxide hydrolase plays an important role during germination of E. lagascae seeds.