Format

Send to

Choose Destination

RETRACTED ARTICLE

See: Retraction Notice

Curr Biol. 2011 Mar 22;21(6):520-5. doi: 10.1016/j.cub.2011.02.029.

The AFB4 auxin receptor is a negative regulator of auxin signaling in seedlings.

Author information

1
Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA.

Abstract

The plant hormone auxin is perceived by a family of F box proteins called the TIR1/auxin-signaling F box proteins (AFBs). Phylogenetic studies reveal that these proteins fall into four clades in flowering plants called TIR1, AFB2, AFB4, and AFB6. Genetic studies indicate that members of the TIR1 and AFB2 groups act as positive regulators of auxin signaling. In this report, we demonstrate a unique role for the AFB4 clade. Both AFB4 and AFB5 function as auxin receptors based on in vitro assays. However, unlike other members of the family, loss of AFB4 results in a range of growth defects that are consistent with auxin hypersensitivity, including increased hypocotyl and petiole elongation and increased numbers of lateral roots. Indeed, qRT-PCR experiments show that afb4-2 is hypersensitive to indole-3-acetic acid (IAA) in the hypocotyl, indicating that AFB4 is a negative regulator of auxin response. Furthermore, we show that AFB4 has a particularly important role in the response of seedlings to elevated temperature. Finally, we provide evidence that the AFB4 clade is the major target of the picloram family of auxinic herbicides. These results reveal a previously unknown aspect of auxin receptor function.

PMID:
21396817
PMCID:
PMC4295904
DOI:
10.1016/j.cub.2011.02.029
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center