Substituted Phthalimide AC94377 Is a Selective Agonist of the Gibberellin Receptor GID1

• Published in: Plant physiology (Bethesda) Vol. 173; no. 1; pp. 825 - 835
• Main Authors: Jiang, Kai, Otani, Masato, Shimotakahara, Hiroaki, Yoon, Jung-Min, Park, Seung-Hyun, Miyaji, Tomoko, Nakano, Takeshi, Nakamura, Hidemitsu, Nakajima, Masatoshi, Asami, Tadao
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01.01.2017
• Subjects: Arabidopsis - drug effects; Arabidopsis - metabolism; Arabidopsis Proteins - agonists; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Germination - drug effects; Gibberellins - metabolism; Hypocotyl - drug effects; Nicotiana - genetics; Phthalimides - chemistry; Phthalimides - metabolism; Phthalimides - pharmacology; Plants, Genetically Modified; Receptors, Cell Surface - agonists; Receptors, Cell Surface - chemistry; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Signal Transduction - drug effects; SIGNALING AND RESPONSE
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.16.00937

Gibberellin (GA) is a major plant hormone that regulates plant growth and development and is widely used as a plant growth regulator in agricultural production. There is an increasing demand for function-limited GA mimics due to the limitations on the agronomical application of GA to crops, including GA's high cost of producing and its leading to the crops' lodging. AC94377, a substituted phthalimide, is a chemical that mimics the growth-regulating activity of GAs in various plants, despite its structural difference. Although AC94377 is widely studied in many weeds and crops, its mode of action as a GA mimic is largely unknown. In this study, we confirmed that AC94377 displays GA-like activities in Arabidopsis (Arabidopsis thaliana) and demonstrated that AC94377 binds to the Arabidopsis GIBBERELLIN INSENSITIVE DWARF1 (GID1) receptor (AtGID1), forms the AtGID1-AC94377-DELLA complex, and induces the degradation of DELLA protein. Our results also indicated that AC94377 is selective for a specific subtype among three AtGID1s and that the selectivity of AC94377 is attributable to a single residue at the entrance to the hydrophobic pocket of GID1. We conclude that AC94377 is a GID1 agonist with selectivity for a specific subtype of GID1, which could be further developed and used as a function-limited regulator of plant growth in both basic study and agriculture.