THE PLANT CELL, Vol 1, Issue 6 569-578, Copyright © 1989 by American Society of Plant Biologists
Tissue-Specific Expression of a Wheat High Molecular Weight Glutenin Gene in Transgenic Tobacco
L. S. Robert, R. D. Thompson and R. B. Flavell
AFRC Institute of Plant Science Research, Cambridge Laboratory, Maris Lane, Trumpington, Cambridge CB2 2JB, United Kingdom
The expression of a wheat genomic clone containing the entire coding
sequence of the high molecular weight glutenin subunit 12 gene flanked by
2.6 kilobases of 5[prime] and 1.5 kilobases of 3[prime] sequences has been
studied after introduction into tobacco. Seeds of different tobacco plants
containing the full-length wheat genomic clone accumulated different
amounts of intact high molecular weight glutenin subunit mRNA and of a
polypeptide displaying the solubility, molecular weight, and antigenic
properties of the high molecular weight glutenin subunit 12. The wheat
protein accumulated without obvious degradation products and constituted up
to approximately 0.1% of the total tobacco endosperm protein. Restriction
fragments corresponding to 2.6 kilobases, 1.4 kilobases, and 433 base pairs
of high molecular weight glutenin 5[prime] upstream sequence were fused to
the coding sequence of the chloramphenicol acetyltransferase (CAT) gene in
the vector polyCATter and transferred into tobacco. Chloramphenicol
acetyltransferase enzyme activity was detected only in the seed endosperm
tissue of the transformed plants. It was detected in tobacco seeds 8 days
after anthesis and persisted until seed maturity. It is concluded that 433
base pairs of high molecular weight glutenin upstream sequence are
sufficient to confer endosperm-specific expression of this monocot gene in
the dicot tobacco.
