THE PLANT CELL, Vol 4, Issue 12 1549-1559, Copyright © 1992 by American Society of Plant Biologists
Spatial and Temporal Gene Expression Patterns Occur during Corm Development
LAB. de Castro, M. Carneiro, D. de C.M. Neshich and G. R. de Paiva
Centro Nacional de Recursos Geneticos e Biotecnologia, C.P. 102372, Brasilia DF, 70770, Brazil
We investigated gene expression patterns that occur during taro corm
development. Two-dimensional gel electrophoresis identified several
different prevalent proteins that accumulate during corm development.
Microsequencing studies indicated that some of these proteins are related
to taste-modifying proteins, such as curculin and miraculin, and proteins
found in other storage organs, such as sporamin and the Kunitz trypsin
inhibitor. A curculin-encoding cDNA clone, designated as TC1, was
identified that corresponds to a highly prevalent 1-kb corm mRNA. The TC1
mRNA accumulates during corm development, is more prevalent in corm apical
than basal regions, and is either absent, or present at low concentrations,
in other vegetative organs such as the leaf and root. In situ hybridization
experiments showed that the TC1 mRNA is highly concentrated in corm storage
parenchyma cells and is absent, or present in reduced concentrations, in
other corm cells and tissues. Our results show that corm development is
associated with the differentiation of specialized cells and tissues, and
that these differentiation events are coupled with the temporal and spatial
expression of corm-specific genes.
