Purification of a Jojoba Embryo Wax Synthase, Cloning of its cDNA, and Production of High Levels of Wax in Seeds of Transgenic Arabidopsis

Abstract

Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a ␤-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua.13 C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

Fatty-acid alkyl esters in table olives in relation to abnormal fermentation and poorly conducted technological treatments

“…KAL and KALT ('Kalamata' raw and natural olives, respectively); MOR and MORT ('Moresca' raw and natural olives, respectively); GIA and GIAT ('Giarraffa' raw and alkaline-treated olives, respectively); NOC and NOCT ('Nocellara del Belice' raw and alkaline-treated olives, respectively). acyl-CoAs ranging from C14 to C24, with C20:1 as the preferred substrate, and it shows the highest activity with C18:1 alcohol (Lardizabal et al, 2000). The third type is the Acinetobacter calcoaceticus WS enzyme, which shows both WS activity and DGAT activity.…”

Exploiting Natural Variation to Uncover an Alkene Biosynthetic Enzyme in Poplar

“…The pathway then branches to produce several compound classes differing in decorating functionality: one branch produces alkanes, secondary alcohols, and ketones (alkaneforming pathway), while another produces primary alcohols and wax esters (alcohol-forming pathway). The products of these pathways are widespread in plant cuticular waxes, and many of the enzymes involved have been characterized (Bernard and Joubès, 2013;Samuels et al, 2008;Yeats and Rose, 2013;Metz et al, 2000;Lardizabal et al, 2000;Rowland et al, 2006). In contrast, it is much less clear how alkenes, cyclopropanes, and internally branched alkanes are synthesized, but this is proposed to occur via an uncharacterized enoic pathway (von WettsteinKnowles, 2007).…”

Synthesis of Novel Lipids in Saccharomyces cerevisiae by Heterologous Expression of an Unspecific Bacterial Acyltransferase

“…The present study aimed at the heterologous expression of functional WS/DGAT in S. cerevisiae since this attempt had failed for the WS from jojoba (Simmondsia chinensis), which was the first enzyme exhibiting WS activity characterized at a molecular level (18). The influence of WS/DGAT expression on the synthesis of TAGs, steryl esters, and other fatty acid esters in yeast was analyzed.…”