GIBBERELLIN INSENSITIVE DWARF1 encodes a soluble receptor for gibberellin

• Published in: Nature 2005-09, Vol.437 (7059), p.693-698
• Main Authors: Ueguchi-Tanaka, M, Ashikari, M, Nakajima, M, Itoh, H, Katoh, E, Kobayashi, M, Chow, T.Y, Hsing, Y.C, Kitano, H, Yamaguchi, I
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; binding capacity; binding proteins; Binding, Competitive; Biological and medical sciences; Cloning, Molecular; dissociation; Epistasis, Genetic; exons; Freshwater; Fundamental and applied biological sciences. Psychology; Gene expression; genes; Genes, Plant - genetics; Genotype & phenotype; gibberellins; Gibberellins - metabolism; Gibberellins - pharmacology; Humanities and Social Sciences; introns; Molecular Sequence Data; multidisciplinary; mutants; Mutation; Mutation - genetics; nucleotide sequences; Oryza - drug effects; Oryza - genetics; Oryza - metabolism; Oryza sativa; Phenotype; Plant growth; Plant physiology and development; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plant reproduction; Protein Binding; protein-protein interactions; receptors; rice; Science; Science (multidisciplinary); Senescence and abscission; signal transduction; Solubility; Sterol Esterase - chemistry; Vegetative apparatus, growth and morphogenesis. Senescence; Yeasts
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature04028

Gibberellins (GAs) are phytohormones that are essential for many developmental processes in plants. It has been postulated that plants have both membrane-bound and soluble GA receptors; however, no GA receptors have yet been identified. Here we report the isolation and characterization of a new GA-insensitive dwarf mutant of rice, gid1. The GID1 gene encodes an unknown protein with similarity to the hormone-sensitive lipases, and we observed preferential localization of a GID1-green fluorescent protein (GFP) signal in nuclei. Recombinant glutathione S-transferase (GST)-GID1 had a high affinity only for biologically active GAs, whereas mutated GST-GID1 corresponding to three gid1 alleles had no GA-binding affinity. The dissociation constant for GA₄ was estimated to be around 10⁻⁷ M, enough to account for the GA dependency of shoot elongation. Moreover, GID1 bound to SLR1, a rice DELLA protein, in a GA-dependent manner in yeast cells. GID1 overexpression resulted in a GA-hypersensitive phenotype. Together, our results indicate that GID1 is a soluble receptor mediating GA signalling in rice.