Abstract
The analysis of cell specificity of gene expression is important to understand the state of differentiation for (particular) vascular cells. We selectively killed developing tracheary element (TE) cells in Zinnia TE-inductive suspension culture to obtain mRNA samples from live TE-free cell population. A comprehensive gene expression analysis on such mRNA samples by DNA microarray revealed that there are significant differences in TE specificity among expression patterns of previously annotated "TE-associated" or "TE-specific" genes.
We identified putative Arabidopsis homologs of some of these Zinnia genes to examine their promoter activities in situ. Arabidopsis transformants containing reporter genes fused with promoter regions of these homolog genes showed signal patterns that are compatible with above microarray data. These findings provide important insights into mechanisms of vascular cell differentiation and TE programmed cell death/autolysis.
