Auxin-sensitive elements from promoters of tobacco GST genes and a consensus as-1-like element differ only in relative strength.
We have investigated the cis-acting potential of several as elements (20-bp as-1/ocs-like sequences) in both yeast and plant cells. These TGACG[N7]TGACG-resembling elements were surprisingly similar with respect to their ability to confer inducibility by auxins and related compounds to a heterologous TATA box in stably transformed plant cells. Both in plant cells and in yeast it was found that differences between as elements were of a quantitative nature. A strong element based on the consensus sequence for as elements conferred the highest level of gene expression. The rather aberrant as elements present in the promoters of auxin-inducible gst genes Nt103 and Nt114 of tobacco were much weaker cis-acting elements. The ability of an element to drive reporter gene expression was found to correlate with the extent to which proteins present in (nuclear) extracts of yeast and plant cells bound to it. The cloned transcription factor TGA1a was shown to be a very good candidate to be the factor that mediates the in vivo regulation of gene expression via as elements. The physiological significance of gene activation by active and inactive auxins is discussed.
van der Zaal
B J
BJ
Institute of Molecular Plant Sciences, Leiden University, Clusius Laboratory, The Netherlands.
Droog
F N
FN
Pieterse
F J
FJ
Hooykaas
P J
PJ
D015084:2,4-Dichlorophenoxyacetic Acid / Q000031:analogs & derivatives; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins / Q000378:metabolism; D004790:Enzyme Induction; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005982:Glutathione Transferase / Q000235:genetics*; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000378:metabolism; D010947:Plants, Toxic; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*; D015533:Transcriptional Activation; D014170:Transformation, Genetic; D015003:Yeasts / Q000235:genetics
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C065794:TGA1a protein, Nicotiana tabacum; D015084:2,4-Dichlorophenoxyacetic Acid; D005982:Glutathione Transferase