Studies of wax ester production and biochemical characterization of jojoba-type wax synthase in Arabidopsis thaliana

• Main Author: Liang, Wei-Wan Scott
• Format: Thesis
• Language: English
• Published: University of British Columbia 2011
• Subjects: Antarctic; Arctic; Antarc*
• Online Access: http://hdl.handle.net/2429/39790

Wax esters are components of surface lipids, serving as surface protectants for both terrestrial plants and animals. Wax esters are also specialized energy storage reserves for the organisms living in extreme environments, such as marine animals in Arctic and Antarctic oceans, the jojoba plant in the desert, and Acinetobacter species in the soil. Wax esters are also important substrates for industrial applications, such as the production of biodiesel, lubricants, cosmetics and polishes. Our current sources and production methods of wax esters from living organisms are not sufficient to meet market demands, so alternative sources including engineered oil crops that can generate sufficient amounts of wax esters are being sought. For my MSc project, I 1) investigated the feasibility of producing high levels of wax esters in the seed of Arabidopsis thaliana; 2) attempted to biochemically characterize new wax ester synthases that share amino acid similarity to the jojoba wax ester synthase; and 3) studied the promoter activity of the wax ester synthase encoded by the At5g55330 gene in Arabidopsis thaliana by a GUS assay. The first objective has been achieved, and the jojoba-type wax esters accumulated when the jojoba wax ester biosynthetic pathway was introduced in the seeds of Arabidopsis. I found that the enzyme encoded by the At5g55330 gene has wax ester synthase activity, but I was unable to characterize its substrate specificity. The third objective is still in progress, but my preliminary results to date indicate that the At5g55330 gene is transcribed in specific tissues of flowers, leaves, stem, and siliques.