Helminthosporic acid functions as an agonist for gibberellin receptor

• Published in: Bioscience, biotechnology, and biochemistry Vol. 81; no. 11; pp. 2152 - 2159
• Main Authors: Miyazaki, Sho, Jiang, Kai, Kobayashi, Masatomo, Asami, Tadao, Nakajima, Masatoshi
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 02.11.2017; Oxford University Press
• Subjects: Arabidopsis - metabolism; Bridged-Ring Compounds - metabolism; Bridged-Ring Compounds - pharmacology; GA-like; gibberellin; Gibberellins - metabolism; helminthosporic acid; helminthosporol; Molecular Docking Simulation; natural product; Oryza - metabolism; Plant Proteins - agonists; Plant Proteins - chemistry; Plant Proteins - metabolism; Protein Conformation; Receptors, Cell Surface - agonists; Receptors, Cell Surface - chemistry; Receptors, Cell Surface - metabolism; helminthosporol; GA-like; helminthosporic acid; gibberellin; natural product
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1080/09168451.2017.1381018

Helminthosporol was isolated from a fungus, Helminthosporium sativum, as a natural plant growth regulator in 1963. It showed gibberellin-like bioactivity that stimulated the growth of the second leaf sheath of rice. After studying the structure-activity relationship between the compound and some synthesized analogs, it was found that helminthosporic acid (H-acid) has higher gibberellin-like activity and chemical stability than helminthosporol. In this study, we showed that (1) H-acid displays gibberellin-like activities not only in rice but also in Arabidopsis, (2) it regulates the expression of gibberellin-related genes, (3) it induces DELLA degradation through binding with a gibberellin receptor (GID1), and (4) it forms the GID1-(H-acid)-DELLA complex to transduce the gibberellin signal in the same manner as gibberellin. This work shows that the H-acid mode of action acts as an agonist for gibberellin receptor. Helminthosporic acid, a synthetic analog of fungus plant growth regulator "helminthosporol", acts as an agonist for gibberellin receptor.