The nitrogen response of a barley C-hordein promoter is controlled by positive and negative regulation of the GCN4 and endosperm box.
The 431 bp C-hordein promoter of lambda-1-17 exhibits a specific response to amino acids and NH4NO3 in developing barley (Hordeum vulgare L.) endosperms. With the aid of particle bombardment it is shown that the GCN4 motif ATGA(C/G)TCAT is the dominating cis-acting element in this response. But synergistic interaction with the neighbouring endosperm motif TGTAAAGT within the bifactorial prolamin element and cooperation with upstream sequences including a second prolamin-like element is an absolute requirement for a strong, positive regulation by an optimal nitrogen regime. Low nitrogen levels convert the GCN4 box into a negative motif. In contrast the endosperm box on its own exerted a silencing activity, independent of nitrogen nutrition. Sequence comparisons revealed that GCN4- and endosperm-like motifs are widely distributed among plant promoters. Their putative role in nitrogen regulation is discussed.
Müller
M
M
Carlsberg Laboratory, Department of Physiology, Gamle Carlsberg Vej 10, Copenhagen Valby, Denmark.
Knudsen
S
S
D001483:Base Sequence; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D017343:Genes, Plant; D005983:Glutens; D001467:Hordeum / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D055315:Prolamins; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion
D010940:Plant Proteins; D055315:Prolamins; D005983:Glutens; D004247:DNA