Related Experiment Video
Updated: Jul 3, 2026

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
Auxin receptors and plant development: a new signaling paradigm
Keithanne Mockaitis1, Mark Estelle
1Department of Biology, Indiana University, Bloomington, Indiana 47405, USA. kmockait@indiana.edu
Abstract:
The plant hormone auxin, in particular indole-3-acetic acid (IAA), is a key regulator of virtually every aspect of plant growth and development. Auxin regulates transcription by rapidly modulating levels of Aux/IAA proteins throughout development. Recent studies demonstrate that auxin perception occurs through a novel mechanism. Auxin binds to TIR1, the F-box subunit of the ubiquitin ligase complex SCF(TIR1), and stabilizes the interaction between TIR1 and Aux/IAA substrates. This interaction results in Aux/IAA ubiquitination and subsequent degradation. Regulation of the Aux/IAA protein family by TIR1 and TIR1-like auxin receptors (AFBs) links auxin action to transcriptional regulation and provides a model by which the vast array of auxin influences on development may be understood. Moreover, auxin receptor function is the first example of small-molecule regulation of an SCF ubiquitin ligase and may have important implications for studies of regulated protein degradation in other species, including animals.
Related Concept Videos
Cell Signaling in Plants
Photoreceptors and Plant Responses to Light
Short-distance Transport of Resources
Plant Hormones
Plant Hormones
Morphogenesis

