PLANT PHYSIOLOGY , Vol 109, Issue 1 73-85, Copyright © 1995 by American Society of Plant Biologists
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GENE REGULATION AND MOLECULAR GENETICS |
Transgenic Analysis of a Hybrid Poplar Wound-Inducible Promoter Reveals Developmental Patterns of Expression Similar to That of Storage Protein Genes
J. B. Hollick and M. P. Gordon
University of Washington, Department of Biochemistry, Box 357350, Seattle, Washington 98195-7610
The wound-inducible win3 multigene family from hybrid poplars (Populus
trichocarpa x Populus deltoides) encodes proteins with structural
similarities with Kunitz-type protease inhibitors (H.D. Bradshaw Jr., J.B.
Hollick, T.J. Parsons, H.R.G. Clarke, M.P. Gordon [1990] Plant Mol Biol 14:
51-59), and at least one member, win3.12, is transcribed de novo in the
injured and uninjured leaves of wounded trees (J.B. Hollick, M.P. Gordon
[1993] Plant Mol Biol 22: 561-572). A previous study demonstrated that 1352
bp of 5[prime] flanking DNA from the win3.12 gene confers local
wound-regulated expression of the [beta]-glucuronidase gene in transgenic
tobacco (Nicotiana tabacum cv Xanthi n.c.) (J.B. Hollick, M.P. Gordon
[1993] Plant Mol Biol 22: 561-572). We extend this transgenic analysis here
by examining the developmental regulation and systemic wound induction
conferred by the same transgene construct in tobacco. Biochemical and
histochemical surveys of [beta]-glucuronidase activity are described for
four, independent transgenic lines. The observed spatial and temporal
expression patterns coincide with dormant storage tissues and with
previously described expression patterns for both seed and vegetative
storage protein genes. Developmental northern blot analysis of win3 RNA
levels in poplar seeds confirms that proper temporal expression of the
reporter gene is maintained during tobacco seed maturation. These results
demonstrate that a putative Kunitz-type protease inhibitor can be wound
inducible in addition to being expressed in developing seeds.
