Abstract
The establishment of single-celled leaf hairs (trichomes) from pluripotent epidermal (protodermal) cells provides a powerful system to determine the gene regulatory networks involved in plant cell fate determination. Two transcription factors, GL1 and GL3, have been associated with the initiation of trichome formation. In this study, we combined expression analyses performed in a number of different genotypes to identify a minimal set of ~500 genes associated with trichome formation. We also used ChIP-chip to identify a set of ~20 genes that are immediate targets of GL3 and GL1. As predicted for genes involved in the initiation of epidermal cell fate determination, several of the GL3/GL1 direct targets are expressed early during trichome formation. Co-expression analyses permitted to identify sets of target genes likely downstream of the GL3/GL1 regulated transcription factors, providing the first steps towards building the regulatory network associated with trichome formation.
