Characteristic Of Arabidopsis Expansin AtEXPA1 Gene Expression And Cis-acting Elements Analysis Of Its Promoter

Gene regulation is the focus of molecular biology. The program, time and location of gene expression are controlled by different regulations. The regulations decide the level of gene expression and the order as well.In this investigation, we firstly have a primary study on the characteristic of expansin AtEXPAl expression by RT-PCR. The expression of AtEXPAl is mainly found in lamina. Submergence induces AtEXPAl expression. The cold, ABA, and salt downgrulate AtEXPAl expression.To identify cis-acting elements that mediate expression of AtEXPAl, we clone its promoter and construct promoter-GUS vector. We performed transient expression studies in tobacoo protoplasts. A series of 5' and 3' deletions from promoter fragments were translationally fused to the p-glucuronidase (GUS reporter). A 282-bp fragment showed the strongest expression. Lots of motifs AAAG were found in promoter and these motifs are possible target sites for trans-acting Dof proteins that control light regulation of gene expression. There are elements relating to cold in the position -897 to -626, relating to ABA in the position -626 to -444, relating to salt in the position -626 to -282.All the results above showed that AtEXPAl responds sensitively to environment. The results can provide the theoretic basis to study the machinism of regulating and cis-acting elements in AtEXPAl promoter.