Poster: Lipids & Related Molecules

Abs # 867: CER5 encodes an ABC transporter involved in wax synthesis in Arabidopsis

Presenter:	Pighin, Jamie A, jpighin2002@yahoo.ca
Authors	Pighin, Jamie A (A)   Balakshin, Laura  (A)   Western, Tamara  (A)   Kunst, Ljerka  (A)   Samuels, Lacey  (A)
Affiliations:	(A): University of British Columbia

Plant waxes are found on the surface of most plants as a protective layer against many environmental stresses. They are formed from very long chain fatty acid (VLCFA) precursors that are synthesized in the cytoplasm of epidermal cells. There are many eceriferum (cer) mutants of Arabidopsis exhibiting non-waxy stems. The cer5 mutant is intriguing as it exhibits an unusual subcellular phenotype consisting of "trilamellar inclusions" in the epidermal cells. These inclusions appear to be rigid membrane sheets built-up in the cytoplasm, but their composition is unknown. Similar sheets are associated with the human neurodegenerative disorder known as adrenoleukodystrophy (ALD). In ALD, a disrupted ABC transporter involved in VLCFA transport in the membrane of peroxisomes leads to the formation of these trilamellar inclusions. Positional mapping has defined the location of CER5 on chromosome 1. Two ABC transporters are found in this region, but only one has been shown through knockout lines to exhibit a waxless phenotype. Further molecular complementation of the original cer5 mutant and characterization of the Salk T-DNA line containing an insertion in the ABC transporter will be presented. Our results identify the first known function of an ABC transporter in wax production in plants.