Abstract
Arabidopsis seeds contain a lot of oil bodies, which are surrounded by a lipid monolayer and store lipids, mainly triacylglycerols, as nutrient sources for seed germination. Oil bodies possess oleosins as major structural proteins. Oleosins are suggested to have an important role of determination of oil-body sizes. To investigate a physiological function of oleosins, we isolated three oleosin-deficient mutants of Arabidopsis thaliana (ole1, ole2 and ole3) and generated double mutants by crossing single mutants. The plants and seeds of these mutants exhibited no visible phenotypes under normal growth condition. Each of single mutant exhibited a similar germination rate to ewild tyoe, , while the double mutant ole1 ole2 exhibited clearly reduced germination rates Electron microscopy revealed that the ole1 ole2 seeds had irregularly-shaped oil-containing structures. We suppose that these structures might inhibit seed germination of ole1 ole2. We will discuss about the effect of oleosin-deficiency on the seed germination.
