title: Reduced gibberellin response affects ethylene biosynthesis and responsiveness in the Arabidopsis gai eto2-1 double mutant.
abstract: Ethylene and gibberellins (GAs) control similar developmental processes in plants. The role of ethylene is at least in part to regulate the accumulation of DELLA proteins, key regulators of plant growth, which suppress the GA response. To expand our knowledge of ethylene-GA crosstalk and to reveal how the modulation of the ethylene and GA pathways affects global plant growth, the gibberellin-insensitive (gai), ethylene-overproducing 2-1 (eto2-1) double mutant, which has decreased GA signalling (resulting from gai) and increased ethylene biosynthesis (resulting from eto2-1), was characterized. Both single mutations resulted in reduced elongation growth. The double mutant showed synergistic responses in root and shoot growth, in induction of floral transition, and in inflorescence length, showing that crosstalk between the two pathways occurs in different plant organs throughout development. Furthermore, the altered ethylene-GA interactions affected root-shoot communication, as evidenced by an enhanced shoot:root ratio in the double mutant. When compared with both single mutants and the wild type, double mutants had enhanced content of active GA(4) at both the seedling and the rosette stages, and, unlike the gai mutant, they were sensitive to GA treatment. Finally, it was shown that synergistic responses in the double mutant were not caused by elevated ethylene biosynthesis but that, in the light, enhanced sensitivity to ethylene may, at least in part, be responsible for the observed phenotype.
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Liesbeth
authors: L
authors: De Grauwe
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Laury
authors: L
authors: Chaerle
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Jasper
authors: J
authors: Dugardeyn
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Jan
authors: J
authors: Decat
authors: Crop Performance Improvement Division, Rothamsted Research, Harpenden AL5 2JQ, Herts, UK.
authors: Ivo
authors: I
authors: Rieu
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Wim H
authors: WH
authors: Vriezen
authors: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 87 Umeå, Sweden.
authors: Thomas
authors: T
authors: Moritz
authors: Plant Systems Biology, Flemish Institute of Biology (VIB)/Ghent University, Technologiepark 927, B-9052 Gent, Belgium.
authors: Gerrit T S
authors: GTS
authors: Beemster
authors: Crop Performance Improvement Division, Rothamsted Research, Harpenden AL5 2JQ, Herts, UK.
authors: Andy L
authors: AL
authors: Phillips
authors: John Innes Centre, Norwich NR4 7UJ, UK.
authors: Nicholas P
authors: NP
authors: Harberd
authors: Crop Performance Improvement Division, Rothamsted Research, Harpenden AL5 2JQ, Herts, UK.
authors: Peter
authors: P
authors: Hedden
authors: Unit Plant Hormone Signaling and Bio-Imaging, Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors: Dominique
authors: D
authors: Van Der Straeten
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000096:biosynthesis* / Q000494:pharmacology; D035264:Flowers; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D036226:Seedlings; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; C109555:GAI protein, Arabidopsis; D005875:Gibberellins; C036216:ethylene