Identification of genes regulated by the transcriptional corepressor TOPLESS in the moss Physcomitrium patens.

Regulation of gene expression is critical for normal plant development. The plant transcriptional corepressor TOPLESS (TPL) is involved in a myriad of processes throughout development in angiosperms, but little is known about its roles in early land plants or how its function has evolved. To address this, we examined TPL function in the moss Physcomitrium patens. Using a transcriptomics approach we identified genes from a variety of pathways, including hormone responses, cell wall biosynthesis, flavonoid biosynthesis and the cell cycle, that were altered in plants with reduced TPL activity. This is the first global analysis of gene expression regulated by this critical corepressor in any plant.