Abstract
During the maturation of Arabidopsis seeds, a large portion of sugars imported from the source are converted into oil for storage. A double-AP2 domain transcription factor ASML1/WRI1 directly activates genes for fatty acid synthesis in the plastid, while the activation of genes for the synthesis of triacylglycerol (TAG) in the ER requires additional factors. To search for such factors, a luciferase (LUC) reporter gene with the promoter of a gene for diacylglycerol acyltransferase (DGAT1) was introduced into Arabidopsis. In addition to strong expression in maturing seeds, the DGAT1p::LUC plants showed LUC expression in leaves of young seedlings, similar to the expression of DGAT1 mRNA. EMS-treated seeds of the DGAT1p::LUC plants screened for mutants with reduced LUC expression in seedlings by using the real-time bioluminescence monitoring system. Most of the mutants that consistently exhibit low LUC expression in the M3 generation showed reduced bioluminescence in developing seeds and reduced seed oil content. We are screening for more mutants and trying to identify genes responsible for these mutants by next-generation sequencer.
