The plant hormone auxin is a key regulator of proper plant development. Failure to properly respond to auxin leads to the inability to develop a root and vasculature during Arabidopsis embryogenesis. Szemenyei et al. now show that TOPLESS is an integral cofactor required for proper auxin response through the AUX/IAA pathway. These data provide insight into the mechanism by which auxin-mediated transcription directs plant development.
H. Szemenyei, M. Hannon, J. A. Long, TOPLESS mediates auxin-dependent transcriptional repression during Arabidopsis embryogenesis. Science 319, 1384-1386 (2008). [Abstract] [Full Text]