Human Metabolic Disease Leads to New Understanding of Oil Accumulation in Plants

The Science

A major challenge in developing plants for biofuels production is the difficulty involved in breaking down lignocellulosic material, the main constituent of plant biomass. An alternate approach to biofuel production in plants would involve engineering plants to accumulate larger amounts of lipids (the precursors of oils normally found in seeds) in vegetative tissues such as leaves. Lipids and oils could then be directly harvested for biodiesel or converted to other biofuels. DOE researchers at the University of North Texas recently identified a gene in the model plant Arabidopsis thaliana that is surprisingly similar to a gene known to be involved in Chanarin-Dorfman syndrome, a human metabolic disorder that results in excessive production of lipids in non-fatty tissues. When this gene was disrupted in Arabidopsis, plants had a 10-fold increase in total lipid content in vegetative plant tissue although the plants appeared to grow normally. Lipid levels in seeds were unchanged. These results suggest a surprising degree of similarity of lipid metabolism between plants and animals. Although Arabidopsis is unlikely to be developed as a bioenergy feedstock, this represents a major advance in understanding of oil synthesis in plants and presents promising new targets for metabolic engineering of biomass crops.

Summary

James, C.N., P. J. Horn, C. R. Case, S. K. Gidd, D. Zhang, R. T. Mullen, J. M. Dyer, R. G. W. Anderson, and K. D. Chapman. 2010. “Disruption of the Arabidopsis CGI-58 Homologue Produces Chanarin–Dorfman-like Lipid Droplet Accumulation in Plants,” Proceedings of the National Academy of Sciences USA 107, 17833–8.