THE PLANT CELL, Vol 1, Issue 5 533-540, Copyright © 1989 by American Society of Plant Biologists
Expression of a Patatin-like Protein in the Anthers of Potato and Sweet Pepper Flowers
G. Vancanneyt, U. Sonnewald, R. Hofgen and L. Willmitzer
Institut fur Genbiologische Forschung GmbH, Ihnestrasse 63, D-1000 Berlin 33, Federal Republic of Germany
Patatin, the major glycoprotein in potato tubers, is encoded by a multigene
family. RNA and protein analyses reveal that a homologous mRNA and an
immunologically cross-reacting protein can be found in potato flowers,
which is similar to patatin in that it displays a lipid acyl hydrolase
activity. The patatin-like protein found in flowers has a higher molecular
weight than the authentic tuber patatin. Deglycosylation experiments show
that this is not due to differences in the glycosylation pattern.
Immunocytochemical analysis shows the patatin-like protein to be present
only in the epidermal cell layer of the anther, the exothecium, and in
petals of potato flowers. Furthermore, the fact that a patatin-like protein
can be detected in a similar tissue in sweet pepper, another solanaceous
plant, could give a clue concerning the evolutionary origin of patatin.
