Amino Acid Regulation in Rice: Integrated Mechanisms and Agricultural Applications

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.