FUNCTIONAL ELEMENTS OF THE ARABIDOPSIS-ADH PROMOTER INCLUDE THE G-BOX

The alcohol dehydrogenase (Adh) gene of Arabidopsis is expressed constitutively in immature seedlings and cells in suspension, and may be induced by hypoxic stress only in roots of mature plants. Deletions and G-box mutations of the Adh promoter were assayed in Arabidopsis protoplasts by PEG-mediated transient expression. Sequence domains necessary for full gene activity are confined to the 384 bp immediately 5' to the transcription start site, and deletion to -177 results in >90% reduction in promoter activity. Site-specific mutations of G-box bases result in > 60% reduction in activity and disrupt G-box factor binding in vitro.