Amino Acid Regulation in Rice: Integrated Mechanisms and Agricultural Applications
Hangfei Luo, Bowen Wu, Bakht Amin, Jiaxu Li, Zhongbo Chen, Jian Shi, Weiting Huang, Zhongming Fang
Abstract
This review synthesizes how amino acid (AA) metabolism regulates rice stress tolerance, growth and quality through stress protection and growth-modulating pathways, bridging mechanisms to field applications. Under abiotic stresses, rice accumulates specific AAs-notably proline (Pro), γ-aminobutyric acid (GABA), and branched-chain AAs (BCAAs)-as osmoprotectants and antioxidants, correlating strongly with stress tolerance. Genetic evidence establishes causality: overexpression of biosynthetic genes (e.g., OsOAT for Pro, OsDIAT for BCAAs), while suppressing catabolism (e.g., OsProDH knockout) or engineering AA transporters (AATs) (e.g., ABA-induced OsANT1 for amino acids redistribution) enhances tolerance. Integrated AA biosynthetic, catabolic, and transport pathways collectively maintain cellular function under stress. These insights enable practical strategies: exogenous AA treatments (e.g., Pro, GABA) mitigate stress damage, while breeding/engineering (e.g., OsAAP3, OsAAP11, and OsProDH knockout) develops high-yield, high-quality, and stress-tolerant rice. Future work should translate molecular insights into field applications, addressing trade-offs between growth, nutrition, and tolerance to enhance climate-resilient rice production.