THE PLANT CELL, Vol 5, Issue 8 855-863, Copyright © 1993 by American Society of Plant Biologists
Distinct cis-Acting Elements Direct Pistil-Specific and Pollen-Specific Activity of the Brassica S Locus Glycoprotein Gene Promoter
V. A. Dzelzkalns, M. K. Thorsness, K. G. Dwyer, J. S. Baxter, M. A. Balent, M. E. Nasrallah and J. B. Nasrallah
Section of Plant Biology, Division of Biological Sciences, Cornell University, Ithaca, New York 14853
The promoter of the S Locus Glycoprotein (SLG) gene of Brassica is a
tightly regulated promoter that is active specifically in reproductive
organs. In transgenic tobacco, this promoter is active exclusively in cells
of the pistil and in pollen. We transformed tobacco with truncated versions
of the SLG13 promoter fused to the [beta]-glucuronidase reporter gene. We
show that the promoter has a modular organization and consists of separable
DNA elements that independently specify pistil- and pollen-specific
expression. A 196-bp region (-339 to -143) is sufficient to confer stigma
and style specificity to the marker gene. Two distinct, but functionally
redundant, domains (-415 to -291 and -117 to -8) allow specific expression
of the gene in pollen. The functional domains identified within the SLG13
promoter contain sequence elements that are highly conserved in different
alleles of the SLG gene and in the S Locus Related SLR1 gene.
