Ligand–receptor interactions in plant hormone signaling. (8th January 2021)

• Record Type: Journal Article
• Authors: Takeuchi, Jun; Fukui, Kosuke; Seto, Yoshiya; Takaoka, Yousuke; Okamoto, Masanori
• Is Part Of: Plant journal. Volume 105:Number 2(2021)
• Page Start: 290
• Page End: 306
• Publication Date: 2021-01-08
• Subjects: plant hormone -- receptor -- protein structure -- signal transduction; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.15115
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Small‐molecule plant hormones principally control plant growth, development, differentiation, and environmental responses. Nine types of plant hormones are ubiquitous in angiosperms, and the molecular mechanisms of their hormone actions have been elucidated during the last two decades by genomic decoding of model plants with genetic mutants. In particular, the discovery of hormone receptors has greatly contributed to the understanding of signal transduction systems. The three‐dimensional structure of the ligand–receptor complex has been determined for eight of the nine hormones by X‐ray crystal structure analysis, and ligand perception mechanisms have been revealed at the atomic level. Collective research has revealed the molecular function of plant hormones that act as either molecular glue or an allosteric regulator for activation of receptors. In this review, we present an overview of the respective hormone signal transduction and describe the structural bases of ligand–receptor interactions. Significance Statement: Small‐molecule hormones are ubiquitous across plant species and play vital roles in various aspects of plant life cycles. Hormone receptors are located mostly upstream of signal transduction and regulate hormone action. Although plants produce many diversified small molecules, including primary, secondary, and hormone metabolites, hormone receptors accurately recognize only active hormone molecules and then transmit hormone signals. Structural studies on ligand–receptor complexes have provided clear answers as to how this is achieved.