Abstract
The carrot gene Dc3 is expressed in developing seeds and in vegetative tissues in response to drought and exogenous abscisic acid (ABA). To identify the cis-elements involved in seed-specific expression as well as ABA response, various 5' upstream deletions, including internal deletions, and site-directed mutations were constructed within the context. The Dc3 promoter consists of two regulatory regions. The proximal promoter region (PPR) contains cis-acting elements responsible for the spatial regulation of Dc3 expression in seeds and for response to ABA in vegetative tissues. Developmental regulation of the Dc3 gene expression is controlled by the five embryo-specific motifs (E motifs) in the PPR. The distal promoter region (DPR) contains additional cis-regulatory elements to modulate and expand the dynamic range of gene expression during embryogenesis. The TTTCGTGT (TT) motif in the DPR in combination with the PPR is capable of responding to ABA. Analysis of Dc3 gene expression in Arabidopsis abi mutant backgrounds suggests that two separate signal transduction pathways are involved in Dc3 expression during embryogenesis and under environmental stress.
Chung, Hwa-Jee (1996). Analysis of the 5' upstream region of the carrot Dc3 gene : bipartite structure of the Dc3 promoter for embryo-specific expression and ABA-inducible expression. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1633687.