Abstract
Arabidopsis ASML1/WRI1 is an AP2-type transcription factor identified from wrinkled1 mutant with defects in seed oil accumulation and from asml1 mutant with enhanced expression of sugar-inducible reporter gene. It is thought to be involved in the control of carbon flow from sucrose import to oil accumulation in developing seeds. To identify genes that are regulated by ASML1/WRI1, we performed microarray analysis with over-expression lines. Over-expression of ASML1/WRI1 caused significant increase in expression levels of genes involved in sucrose metabolism and fatty acid synthesis, and expression of these genes was down-regulated in disruptant of ASML1/WRI1. On the contrary, expression of genes for triacylglycerol synthesis in ER and for oil body oleosins was not significantly affected. In protoplast transient assay, ASML1/WRI1 trans-activated expression of LUC reporter under the promoters of several genes involved in fatty acid synthesis. These results suggest that ASML1/WRI1 directly activates genes involved in fatty acid synthesis in plastid.
