Deletion analysis and site-directed mutagenesis of the high-light responsive Elip1 promoter in Arabidopsis thaliana

Plants exposed to high-light (HL) intensities react to photooxidative stress by immediately triggering transcription of nuclear Elip genes that encode early light-inducible proteins. To identify specific regions of the promoter that are responsible for HL-dependent transcription of Arabidopsis Elip1 gene, a 5' deletion analysis was performed. Six Elip1 promoter fragments, ranging from 984 to 159 bp, were ligated next to the GUS reporter gene in pBI101.1 vector. The Elip1/GUS constructs were introduced into Arabidopsis thaliana plants by Agrobacterium-mediated transformation.; In Elip1-159/GUS transgenic lines GUS activity was almost completely abolished, while Elip1-217/GUS deletion lines still showed HL induction comparable to the full-length promoter lines ( Elip1-984/GUS). Site-directed mutagenesis of GATA, CACGTG, and CAAT boxes located between -217 and -1 revealed that neither one of these LREs is crucial for HL-responsive activation of the Arabidopsis Elip1 gene. However, our results suggested that the CAAT and GATA boxes negatively regulate Elip1 transcription under HL stress.