RT Journal Article
SR Electronic
T1 TOPLESS Mediates Auxin-Dependent Transcriptional Repression During <em>Arabidopsis</em> Embryogenesis
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1384
OP 1386
DO 10.1126/science.1151461
VO 319
IS 5868
A1 Szemenyei, Heidi
A1 Hannon, Mike
A1 Long, Jeff A.
YR 2008
UL http://science.sciencemag.org/content/319/5868/1384.abstract
AB The transcriptional response to auxin is critical for root and vascular development during Arabidopsis embryogenesis. Auxin induces the degradation of AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors, freeing their binding partners, the AUXIN RESPONSE FACTOR (ARF) proteins, which can activate transcription of auxin response genes. We show that TOPLESS (TPL) can physically interact with IAA12/BODENLOS (IAA12/BDL) through an ETHYLENE RESPONSE FACTOR (ERF)–associated amphiphilic repression (EAR) motif. TPL can repress transcription in vivo and is required for IAA12/BDL repressive activity. In addition, tpl-1 can suppress the patterning defects of the bdl-1 mutant. Direct interaction between TPL and ARF5/MONOPTEROS, which is regulated by IAA12/BDL, results in a loss-of-function arf5/mp phenotype. These observations show that TPL is a transcriptional co-repressor and further our understanding of how auxin regulates transcription during plant development.