Disruption of the Arabidopsis Cgi-58 Homologue Produces Chanarin-Dorfman-Like Lipid Droplet Accumulation in Plants

CGI-58is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologousCGI-58gene inArabidopsis thalianaresulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets fromcgi-58loss-of-function mutants showed they contain triacylglycerols with common leaf-specific fatty acids. Leaves of maturecgi-58plants exhibited a marked increase in absolute triacylglycerol levels, more than 10-fold higher than in wild-type plants. Lipid levels in the oil-storing seeds ofcgi-58loss-of-function plants were unchanged, and unlike mutations in β-oxidation, thecgi-58seeds germinated and grew normally, requiring no rescue with sucrose. We conclude that the participation ofCGI-58in neutral lipid homeostasis of nonfat-storing tissues is similar, although not identical, between plant and animal species. This unique insight may have implications for designing a new generation of technologies that enhance the neutral lipid content and composition of crop plants.