A 20 nucleotide upstream element is essential for the nopaline synthase (nos) promoter activity

Abstract

The nopaline synthase (nos) promoter is expressed in a wide range of plant cell types and regulated by various developmental and environmental factors. The nos upstream control region essential for this regulation was studied by means of synthetic oligomers using transient and stable transformation systems. Insertion of a 20 nucleotide sequence containing two hexamer motifs and a spacer region into deletion mutants lacking the upstream control region was essential for promoter activity. Mutation of one or more nucleotides of either hexamer sequence significantly altered the strength of expression of the nos promoter. Point mutations within the spacer region also strongly influenced promoter strength. Insertion of multiple copies of the 20 nucleotide sequence into the nonfunctional deletion mutants proportionally increased the promoter activity. These results suggest that this twenty nucleotide sequence is essential for the nos promoter to function. Substitution of the nos element with the ocs or 35S as-1 which contain similar hexamer motifs restored not only promoter activity but also responses to wounding, auxin, methyl jasmonate, and salicylic acid.

The maize geneliguleless2 encodes a basic leucine zipper protein involved in the establishment of the leaf blade–sheath boundary

“…Possible functions for proteins in the subclass of bZIPs that LG2 is a member of have been proposed by studying the cis-binding sequences either transgenically, through fusions with reporter genes, or by studying plant genes with promoters containing the consensus sequence. Hypothesized functions include transcriptional regulation of plant histone (Tabata et al 1991) and GST genes (Ulmasov et al 1994;Zhang et al 1995;Chengbin 1996) as well as auxin, salicylic acid, and methyl jasmonate responses (Kim et al 1994;Liu and Lam 1994;Qin et al 1994;Zhang and Singh 1994;Chengbin 1996). The Lg2+ gene has the first published mutant phenotype associated with this group of proteins and adds a developmental function to the above list.…”

“…We cloned the Lg2+ gene by transposon tagging and it shows sequence homology to the basic leucine zipper (bZIP) class of transcription factors. It is most similar to a subclass of plant DNA-binding proteins characterized biochemically and hypothesized to function in diverse processes (Tabata et al 1991;Kim et al 1994;Liu and Lam 1994;Qin et al 1994;Ulmasov et al 1994;Zhang and Singh 1994;Zhang et al 1995;Chengbin et al 1996). Lg2+ is the first reported gene within this group with an associated mutant phenotype.…”

Interactions between distinct types of DNA binding proteins enhance binding to ocs element promoter sequences.

“…The ocs element in the cauliflower mosaic virus (CaMV) 35s promoter is also called as-7 (Lam et al, 1989). Genes containing ocs element sequences are activated by auxin and salicylic acid (SA) in a number of plants (Kim et al, 1994;Liu and Lam, 1994;Qin et al, 1994;Ulmasovet al, 1994;Zhang and Singh, 1994). In Arabidopsis, the activity of ocs element sequences in response to auxin is highest in the root tip region .…”

Induction of Nopaline Synthase Promoter Activity by H2O2 Has No Direct Correlation with Salicylic Acid

“…Previous studies have shown that the nos promoter is induced by wounding, auxin, SA, and MJ Kim et al, 1993Kim et al, ,1994). The present study shows that H 2 O 2 also induces nos promoter activity.…”

“…These studies revealed that the nos upstream region is essential for the responses to these stimuli. Site-specific mutations and fine deletion analysis of the nos promoter upstream region showed that a 20-nucleotide regulatory element located between -131 and -112 is essential for the promoter activity (Kim et al, 1994). The element consists of ' This work was supported in part by National Science Foun-* Corresponding author; e-mail daizy@wsunix.wsu.edu; fax dation grant No.…”