Research & Teaching Faculty

Default Header Image

Identification of the wax ester synthase/acyl-coenzyme A: Diacylglycerol acyltransferase WSD1 required for stem wax ester biosynthesis in Arabidopsis

TitleIdentification of the wax ester synthase/acyl-coenzyme A: Diacylglycerol acyltransferase WSD1 required for stem wax ester biosynthesis in Arabidopsis
Publication TypeJournal Article
Year of Publication2008
AuthorsLi, F, Wu, X, Lam, P, Bird, D, Zheng, H, Samuels, L, Jetter, R, Kunst, L
JournalPlant Physiology
Volume148
Pagination97-107
Date PublishedSep
Type of ArticleArticle
ISBN Number0032-0889
KeywordsABC, CLONING, CONDENSING ENZYME, ELONGATION, GENE-EXPRESSION, PLANT CUTICULAR WAXES, SURFACES, THALIANA, TRANSFORMATION, TRANSGENIC ARABIDOPSIS, TRANSPORTER
Abstract

Wax esters are neutral lipids composed of aliphatic alcohols and acids, with both moieties usually long-chain (C-16 and C-18) or very-long-chain (C-20 and longer) carbon structures. They have diverse biological functions in bacteria, insects, mammals, and terrestrial plants and are also important substrates for a variety of industrial applications. In plants, wax esters are mostly found in the cuticles coating the primary shoot surfaces, but they also accumulate to high concentrations in the seed oils of a few plant species, including jojoba (Simmondsia chinensis), a desert shrub that is the major commercial source of these compounds. Here, we report the identification and characterization of WSD1, a member of the bifunctional wax ester synthase/diacylglycerol acyltransferase gene family, which plays a key role in wax ester synthesis in Arabidopsis (Arabidopsis thaliana) stems, as first evidenced by severely reduced wax ester levels of in the stem wax of wsd1 mutants. In vitro assays using protein extracts from Escherichia coli expressing WSD1 showed that this enzyme has a high level of wax synthase activity and approximately 10-fold lower level of diacylglycerol acyltransferase activity. Expression of the WSD1 gene in Saccharomyces cerevisiae resulted in the accumulation of wax esters, but not triacylglycerol, indicating that WSD1 predominantly functions as a wax synthase. Analyses of WSD1 expression revealed that this gene is transcribed in flowers, top parts of stems, and leaves. Fully functional yellow fluorescent protein-tagged WSD1 protein was localized to the endoplasmic reticulum, demonstrating that biosynthesis of wax esters, the final products of the alcohol-forming pathway, occurs in this subcellular compartment.

URL<Go to ISI>://000258947600010