Ethylene Regulates Arabidopsis Development via the Modulation of DELLA Protein Growth Repressor Function

• Published in: The Plant cell Vol. 15; no. 12; pp. 2816 - 2825
• Main Authors: Achard, Patrick, Vriezen, Wim H., Van Der Straeten, Dominique, Harberd, Nicholas P.
• Format: Journal Article
• Language: English
• Published: England American Society of Plant Biologists 01.12.2003
• Subjects: Arabidopsis; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Auxins; DELLA protein; Ethylenes - pharmacology; Gene expression regulation; Germination - physiology; Gibberellins; Gibberellins - pharmacology; Green Fluorescent Proteins; Hypocotyls; Indoleacetic Acids - pharmacology; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Multigene Family; phytohormones; Plant cells; Plant growth regulators; Plant Growth Regulators - pharmacology; Plant Proteins; Plant roots; Plant Roots - drug effects; Plant Roots - genetics; Plant Roots - growth & development; Plants; Protein Kinases - genetics; Protein Kinases - metabolism; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Root growth; Seedlings; Seeds - physiology; Signal Transduction - drug effects; Signal Transduction - genetics; Signal Transduction - physiology; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.015685

Phytohormones regulate plant development via a poorly understood signal response network. Here, we show that the phytohormone ethylene regulates plant development at least in part via alteration of the properties of DELLA protein nuclear growth repressors, a family of proteins first identified as gibberellin (GA) signaling components. This conclusion is based on the following experimental observations. First, ethylene inhibited Arabidopsis root growth in a DELLA-dependent manner. Second, ethylene delayed the GA-induced disappearance of the DELLA protein repressor of ga1-3 from root cell nuclei via a constitutive triple response-dependent signaling pathway. Third, the ethylene-promoted "apical hook" structure of etiolated seedling hypocotyls was dependent on the relief of DELLA-mediated growth restraint. Ethylene, auxin, and GA responses now can be attributed to effects on DELLA function, suggesting that DELLA plays a key integrative role in the phytohormone signal response network.