THE PLANT CELL, Vol 2, Issue 1 61-70, Copyright © 1990 by American Society of Plant Biologists
Localization of Elements Important for the Wound-Inducible Expression of a Chimeric Potato Proteinase Inhibitor II-CAT Gene in Transgenic Tobacco Plants
M. Keil, J. Sanchez-Serrano, J. Schell and L. Willmitzer
Institut fur Genbiologische Forschung Berlin GmbH, Ihnestrasse 63, D-1000 Berlin 33, Federal Republic of Germany
The effect of progressive 5[prime] deletions within a potato proteinase
inhibitor II promoter on wound-inducible expression of the chloramphenicol
acetyltransferase (CAT) gene in leaves of transgenic tobacco plants was
analyzed. After deletion of a region ranging from position -1300 to -700
with respect to the transcription start site, promoter activity was
markedly reduced but still wound-inducible. Further deletion of
approximately 200 base pairs resulted in a promoter activity that was below
the detection limit, proving that the activity of the proteinase inhibitor
II promoter is controlled by sequences upstream of position -514. Addition
of the enhancer of the 35S promoter of the cauliflower mosaic virus (CaMV)
either 5[prime] upstream or 3[prime] downstream of chimeric genes
consisting of different proteinase inhibitor II promoter deletions (-700,
-514, -210) fused to the CAT gene led to wound-inducible CAT gene
expression in a fraction of transgenic plants containing either the "-700"
or "-514" promoters, indicating the presence of wound-responsive elements
in the promoter-proximal region. A fragment of the proteinase inhibitor II
promoter comprising sequences between positions -1300 and -195 is able to
confer wound-inducible expression to an inactive CaMV 35S promoter
truncated at position -90 in either orientation, proving that this fragment
displays wound-specific, enhancer-like properties. In addition, data are
presented excluding that the proteinase inhibitor II 3[prime] end is of
importance for wound-inducible gene expression.
