Format

Send to:

Choose Destination
See comment in PubMed Commons below
Plant Cell. 2003 Jun;15(6):1310-9.

Arabidopsis SGT1b is required for SCF(TIR1)-mediated auxin response.

Author information

  • 1Department of Plant Biology, University of Minnesota--Twin Cities, St. Paul, Minnesota 55108, USA. grayx051@tc.umn.edu

Abstract

The SCF(TIR1) complex is a central regulator of the auxin response pathway in Arabidopsis. This complex functions as a ubiquitin protein ligase that targets members of the auxin/indoleacetic acid (Aux/IAA) family of transcriptional regulators for ubiquitin-mediated degradation in response to auxin. In an attempt to identify additional factors required for SCF(TIR1) activity, we conducted a genetic screen to isolate enhancers of the auxin response defect conferred by the tir1-1 mutation. Here, we report the identification and characterization of the eta3 mutant. The eta3 mutation interacts synergistically with tir1-1 to strongly enhance all aspects of the tir1 mutant phenotype, including auxin inhibition of root growth, lateral root development, hypocotyl elongation at high temperature, and apical dominance. We isolated the ETA3 gene using a map-based cloning strategy and determined that ETA3 encodes SGT1b. SGT1b was identified recently as a factor involved in plant disease resistance signaling, and SGT1 from barley and tobacco extracts was shown to interact with SCF ubiquitin ligases. We conclude that ETA3/SGT1b is required for the SCF(TIR1)-mediated degradation of Aux/IAA proteins.

PMID:
12782725
[PubMed - indexed for MEDLINE]
PMCID:
PMC156368
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk