Abstract
Arabidopsis ABI3 gene is known as a transcriptional factor which expresses during plant embryogenesis from very early stage, but the mechanism for regulating the gene expression is still unclear. In our laboratory, C-ABI3, a carrot homologue of ABI3 had been isolated and showed that the expression was observed during somatic and zygotic embryogenesis from the early stage. In this study, we analyzed the mechanism which regulates C-ABI3 expression. At first, C-ABI3 promoter region was isolated, and a cis-regulatory element which relates to regulation of embryo-specific gene expression was identified and named as Carrot Embryonic Element 1 (CEE1). CEE1 regulated embryo-specific gene expression in carrot somatic embryos and Arabidopsis zygotic embryos. Moreover, the existence of some nuclear proteins which interact to CEE1 was suggested by EMSA data. By using yeast-one-hybrid system, we isolated seven CEE1 binding factors (CEE1BFs). All of the CEE1BFs genes expressed in carrot somatic and zygotic embryos.
