PT - JOURNAL ARTICLE AU - Achard, Patrick AU - Vriezen, Wim H. AU - Van Der Straeten, Dominique AU - Harberd, Nicholas P. TI - Ethylene Regulates Arabidopsis Development via the Modulation of DELLA Protein Growth Repressor Function AID - 10.1105/tpc.015685 DP - 2003 Dec 01 TA - The Plant Cell PG - 2816--2825 VI - 15 IP - 12 4099 - http://www.plantcell.org/content/15/12/2816.short 4100 - http://www.plantcell.org/content/15/12/2816.full SO - Plant Cell2003 Dec 01; 15 AB - 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.