PT  - JOURNAL ARTICLE
AU  - Szemenyei, Heidi
AU  - Hannon, Mike
AU  - Long, Jeff A.
TI  - TOPLESS Mediates Auxin-Dependent Transcriptional Repression During <em>Arabidopsis</em> Embryogenesis
AID  - 10.1126/science.1151461
DP  - 2008 Mar 07
TA  - Science
PG  - 1384--1386
VI  - 319
IP  - 5868
4099  - http://science.sciencemag.org/content/319/5868/1384.short
4100  - http://science.sciencemag.org/content/319/5868/1384.full
SO  - Science2008 Mar 07; 319
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.